1
|
Shultz SJ, Morrissey MC, Vauhnik R. Anterior knee laxity is greater in athletic females who attain menarche at a younger age. Knee Surg Sports Traumatol Arthrosc 2024; 32:889-895. [PMID: 38454787 DOI: 10.1002/ksa.12138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/13/2024] [Accepted: 02/20/2024] [Indexed: 03/09/2024]
Abstract
PURPOSE Females with above-average anterior knee laxity values are at increased risk of anterior cruciate ligament (ACL) injury. The purpose of this study was to examine the effects of menarche age (MA) and menarche offset on anterior knee laxity in young, physically active women. METHODS Anterior knee laxity (KT-2000) and menstrual characteristics (per self-report) were recorded in 686 Slovenian sportswomen from team handball, volleyball and basketball club sports (average years sport participation: 7.3 ± 3.6 years). Females were stratified into four groups based on their self-reported age at menarche: 9-11, 12, 13 and 14+ years. Anterior knee laxity was compared across MA groups using a univariate analysis of variance (ANOVA) with Bonferroni correction, with and without controlling for factors that could potentially differ between groups and influence anterior knee laxity. Females were then stratified into four groups based on the number of years they were away from their age at onset of menarche. Groups were compared using a univariate ANOVA with Bonferroni correction, with and without controlling for factors that differed between groups and could influence anterior knee laxity. RESULTS Anterior knee laxity was greater in females who attained menarche at 12 years of age (6.4 ± 1.5 mm) or younger (6.6 ± 1.6 mm) compared to 14 years of age or older (5.8 ± 1.2 mm) (p < 0.001; partial η2 = 0.032). Anterior knee laxity was 0.7-1.4 mm greater in females who were 5 or more years away from menarche compared to those who were within 2 years of menarche (5.8 ± 1.3 mm; p < 0.001). CONCLUSION Anterior knee laxity is greater in females who attained menarche at a younger age and in females who are 5 or more years postmenarche. Age of menarche represents a critical pubertal event that is easy for women to recall and may provide important insights into factors that moderate anterior knee laxity, a risk factor for ACL injury in women. LEVEL OF EVIDENCE Level IV.
Collapse
Affiliation(s)
- Sandra J Shultz
- Department of Kinesiology, University of North Carolina, Greensboro, Greensboro, North Carolina, USA
| | - Matthew C Morrissey
- Biomechanical Laboratory, Department of Physiotherapy, Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - Renata Vauhnik
- Biomechanical Laboratory, Department of Physiotherapy, Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
- Arthron, Institute for Joint and Sports Injuries, Ljubljana, Slovenia
| |
Collapse
|
2
|
Park-Braswell K, Shultz SJ, Ross SE, Sunnassee D, Grooms DR, Schmitz RJ. The Impact of Differential Knee Laxity on Brain Activation During Passive Knee Joint Loading. J Orthop Res 2023; 42:10.1002/jor.25664. [PMID: 37442639 PMCID: PMC10851619 DOI: 10.1002/jor.25664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 07/11/2023] [Indexed: 07/15/2023]
Abstract
Although higher anterior knee laxity is an established risk factor of ACL injury, underlying mechanisms are uncertain. While decreased proprioception and altered movement patterns in individuals with anterior knee laxity have been identified, the potential impact of higher laxity on brain activity is not well understood. Thus, the purpose of this study is to identify the impact of different magnitudes of knee laxity on brain function during anterior knee joint loading. Twenty-seven healthy and active female college students without any previous severe lower leg injuries volunteered for this study. Anterior knee laxity was measured using a knee arthrometer KT-2000 to assign participants to a higher laxity (N=15) or relatively lower laxity group (N=12). Functional magnetic resonance images were obtained during passive anterior knee joint loading in a task-based design using a 3T MRI scanner. Higher knee laxity individuals demonstrated diminished cortical activation in the left superior parietal lobe during passive anterior knee joint loading. Less brain activation in the regions associated with awareness of bodily movements in females with higher knee laxity may indicate a possible connection between brain activity and knee laxity. The results of this study may help researchers and clinicians develop effective rehabilitation programs for individuals with increased knee laxity. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Scott E. Ross
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Devdass Sunnassee
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Dustin R. Grooms
- Ohio Musculoskeletal & Neurological Institute, Ohio University, Athens, Ohio, USA
- Division of Physical Therapy & Division of Athletic Training, College of Health Sciences and Professions, Ohio University, Athens, Ohio, USA
| | - Randy J. Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
- Gateway MRI Center University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| |
Collapse
|
3
|
Kelley EA, Hogg JA, Gao L, Waxman JP, Shultz SJ. Demographic Factors and Instantaneous Lower Extremity Injury Occurrence in a National Collegiate Athletic Association Division I Population. J Athl Train 2023; 58:393-400. [PMID: 35789230 DOI: 10.4085/1062-6050-0673.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Temporal prediction of the lower extremity (LE) injury risk will benefit clinicians by allowing them to better leverage limited resources and target those athletes most at risk. OBJECTIVE To characterize the instantaneous risk of LE injury by demographic factors of sex, sport, body mass index (BMI), and injury history. DESIGN Descriptive epidemiologic study. SETTING National Collegiate Athletic Association Division I athletic program. PATIENTS OR OTHER PARTICIPANTS A total of 278 National Collegiate Athletic Association Division I varsity student-athletes (119 males, 159 females; age = 19.07 ± 1.21 years, height = 175.48 ± 11.06 cm, mass = 72.24 ± 12.87 kg). MAIN OUTCOME MEASURE(S) Injuries to the LE were tracked for 237 ± 235 consecutive days. Sex-stratified univariate Cox regression models were used to investigate the association between time to first LE injury and sport, BMI, and LE injury history. The instantaneous LE injury risk was defined as the injury risk at any given point in time after the baseline measurement. Relative risk ratios and Kaplan-Meier curves were generated. Variables identified in the univariate analysis were included in a multivariate Cox regression model. RESULTS Female athletes displayed similar instantaneous LE injury risk to male athletes (hazard ratio [HR] = 1.29; 95% CI= 0.91, 1.83; P = .16). Overweight athletes (BMI >25 kg/m2) had similar instantaneous LE injury risk compared with athletes with a BMI of <25 kg/m2 (HR = 1.23; 95% CI = 0.84, 1.82; P = .29). Athletes with previous LE injuries were not more likely to sustain subsequent LE injury than athletes with no previous injury (HR = 1.09; 95% CI = 0.76, 1.54; P = .64). Basketball (HR = 3.12; 95% CI = 1.51, 6.44; P = .002) and soccer (HR = 2.78; 95% CI = 1.46, 5.31; P = .002) athletes had a higher risk of LE injury than cross-country athletes. In the multivariate model, instantaneous LE injury risk was greater in female than in male athletes (HR = 1.55; 95% CI = 1.00, 2.39; P = .05), and it was greater in male athletes with a BMI of >25 kg/m2 than that in all other athletes (HR = 0.44; 95% CI = 0.19, 1.00; P = .05), but these findings were not significantly different. CONCLUSIONS In a collegiate athlete population, previous LE injury was not a contributor to the risk of future LE injury, whereas being female or being male with a BMI of >25 kg/m2 resulted in an increased risk of LE injury. Clinicians can use these data to extrapolate the LE injury risk occurrence to specific populations.
Collapse
Affiliation(s)
| | - Jennifer A Hogg
- Department of Health and Human Performance, University of Tennessee at Chattanooga
| | - Lani Gao
- Department of Mathematics, University of Tennessee at Chattanooga
| | | | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro
| |
Collapse
|
4
|
Cerminaro RM, Gardner HM, Shultz SJ, Dollar JM, Wideman L, Duffy DM. The Accuracy of Early Reproductive History and Physical Activity Participation Recall Across Multiple Age Ranges. J Womens Health (Larchmt) 2023. [PMID: 36939903 DOI: 10.1089/jwh.2022.0460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023] Open
Abstract
Background: The ability to accurately recall specific reproductive health events is an integral aspect of medical decision making and evaluating a female's overall health and wellness across their lifespan. The Health and Reproductive Survey (HeRS) was developed to recall reproductive events and environmental influences on reproductive characteristics throughout the lifespan of a female. This study aimed to determine how reliably women recall certain events during menarche and early reproductive years. It was hypothesized that age at menarche, hormonal contraceptive use, and physical activity would be recalled reliably among all age ranges, while the recall reliability for cycle regularity and length would be more inconsistent with advancing age. Materials and Methods: A total of 144 participants (age: 32.73 ± 11.92), completed the HeRS on two occasions spaced 4 months apart to investigate recall reliability. Cohen's kappa coefficient was used to assess the consistency of categorical responses and 95% limits of agreement were used for continuous data. Results: Although physical activity changes had greater variability than anticipated (0.79), the recall reliability among the youngest (1) and oldest (0.89) age groups was high, and females were able to consistently recall the age of menarche (0.83), physical activity level (0.9), cessation of period during early reproductive years (0.91), and birth control use following menarche (0.85) and during the early reproductive years (0.9). Conclusions: The HeRS is a useful tool for reliably recalling reproductive history and physical activity participation across multiple age ranges and can be utilized to gather crucial information throughout the reproductive lifespan.
Collapse
Affiliation(s)
- Rebecca M Cerminaro
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA.,School of Health of Human Sciences, Center for Women's Health and Wellness, UNCG, Greensboro, North Carolina, USA
| | - Hanna M Gardner
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA.,School of Health of Human Sciences, Center for Women's Health and Wellness, UNCG, Greensboro, North Carolina, USA
| | - Jessica M Dollar
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA.,School of Health of Human Sciences, Center for Women's Health and Wellness, UNCG, Greensboro, North Carolina, USA
| | - Laurie Wideman
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Donna M Duffy
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| |
Collapse
|
5
|
Bechke EE, Anderson T, Wideman L, Shultz SJ. Body Fat Percentage Does Not Predict Sex Hormone Variability Within And Between Two Menstrual Cycles. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000882584.57202.0f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
6
|
Shultz SJ, Cruz MR, Casey E, Dompier TP, Ford KR, Pietrosimone B, Schmitz RJ, Taylor JB. Sex-Specific Changes in Physical Risk Factors for Anterior Cruciate Ligament Injury by Chronological Age and Stages of Growth and Maturation From 8 to 18 Years of Age. J Athl Train 2022; 57:830-876. [PMID: 36638346 PMCID: PMC9842121 DOI: 10.4085/1062-6050-0038.22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To critically assess the literature focused on sex-specific trajectories in physical characteristics associated with anterior cruciate ligament (ACL) injury risk by age and maturational stage. DATA SOURCES PubMed, CINAHL, Scopus, and SPORTDiscus databases were searched through December 2021. STUDY SELECTION Longitudinal and cross-sectional studies of healthy 8- to 18-year-olds, stratified by sex and age or maturation on ≥1 measure of body composition, lower extremity strength, ACL size, joint laxity, knee-joint geometry, lower extremity alignment, balance, or lower extremity biomechanics were included. DATA EXTRACTION Extracted data included study design, participant characteristics, maturational metrics, and outcome measures. We used random-effects meta-analyses to examine sex differences in trajectory over time. For each variable, standardized differences in means between sexes were calculated. DATA SYNTHESIS The search yielded 216 primary and 22 secondary articles. Less fat-free mass, leg strength, and power and greater general joint laxity were evident in girls by 8 to 10 years of age and Tanner stage I. Sex differences in body composition, strength, power, general joint laxity, and balance were more evident by 11 to 13 years of age and when transitioning from the prepubertal to pubertal stages. Sex differences in ACL size (smaller in girls), anterior knee laxity and tibiofemoral angle (greater in girls), and higher-risk biomechanics (in girls) were observed at later ages and when transitioning from the pubertal to postpubertal stages. Inconsistent study designs and data reporting limited the number of included studies. CONCLUSIONS Critical gaps remain in our knowledge and highlight the need to improve our understanding of the relative timing and tempo of ACL risk factor development.
Collapse
Affiliation(s)
- Sandra J. Shultz
- Department of Kinesiology, University of North Carolina, Greensboro
| | | | | | | | | | - Brian Pietrosimone
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill
| | - Randy J. Schmitz
- Department of Kinesiology, University of North Carolina, Greensboro
| | | |
Collapse
|
7
|
Shultz SJ, Pietrosimone B. Pediatric Anterior Cruciate Ligament Injuries: We Need to Do Better for Our Most Vulnerable Patients. J Athl Train 2022; 57:828-829. [PMID: 36638342 PMCID: PMC9842118 DOI: 10.4085/1062-6050-1004.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
8
|
Shultz SJ, Montgomery MM, Schmitz RJ, Wideman L. Comparison Of Leg Fat Mass And Lean Mass Indices In Males And Females Stratified By Bmi. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000877112.78533.5c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
9
|
Schmitz RJ, Ford KR, Pietrosimone B, Shultz SJ, Taylor JB. ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina. J Athl Train 2022; 57:990-995. [PMID: 36638340 PMCID: PMC9842120 DOI: 10.4085/1062-6050-0219.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Randy J. Schmitz
- Applied Neuromechanics Research Laboratory, Department of Kinesiology, School of Health and Human Sciences, University of North Carolina, Greensboro
| | - Kevin R. Ford
- Human Biomechanics and Physiology Laboratory, Department of Physical Therapy, High Point University, NC
| | - Brian Pietrosimone
- MOTION Science Institute, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill
| | - Sandra J. Shultz
- Applied Neuromechanics Research Laboratory, Department of Kinesiology, School of Health and Human Sciences, University of North Carolina, Greensboro
| | - Jeffrey B. Taylor
- Human Biomechanics and Physiology Laboratory, Department of Physical Therapy, High Point University, NC
| |
Collapse
|
10
|
Shultz SJ, Schmitz RJ, Kulas AS, Labban JD, Wang HM. Quadriceps muscle volume positively contributes to ACL volume. J Orthop Res 2022; 40:268-276. [PMID: 33506964 DOI: 10.1002/jor.24989] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/12/2020] [Accepted: 01/11/2021] [Indexed: 02/04/2023]
Abstract
Females have smaller anterior cruciate ligaments (ACLs) than males and smaller ACLs have been associated with a greater risk of ACL injury. Overall body dimensions do not adequately explain these sex differences. This study examined the extent to which quadriceps muscle volume (VOLQUAD ) positively predicts ACL volume (VOLACL ) once sex and other body dimensions were accounted for. Physically active males (N = 10) and females (N = 10) were measured for height, weight, and body mass index (BMI). Three-Tesla magnetic resonance images of their dominant and nondominant thigh and knee were then obtained to measure VOLACL , quadriceps, and hamstring muscle volumes, femoral notch width, and femoral notch width index. Separate three-step regressions estimated associations between VOLQUAD and VOLACL (third step), after controlling for sex (first step) and one body dimension (second step). When controlling for sex and sex plus BMI, VOLHAM , notch width, or notch width index, VOLQUAD consistently exhibited a positive association with VOLACL in the dominant leg, nondominant leg, and leg-averaged models (p < 0.05). Findings were inconsistent when controlling for sex and height (p = 0.038-0.102). Once VOLQUAD was included, only notch width and notch width index retained a statistically significant individual association with VOLACL (p < 0.01). Statement of Clinical Significance: The positive association between VOLQUAD and VOLACL suggests ACL size may in part be modifiable. Future studies are needed to determine the extent to which an appropriate training stimulus (focused on optimizing overall lower extremity muscle mass development) can positively impact ACL size and structure in young females.
Collapse
Affiliation(s)
- Sandra J Shultz
- Department of Kinesiology, University of North Carolina Greensboro, Greensboro, North Carolina, USA
| | - Randy J Schmitz
- Department of Kinesiology, University of North Carolina Greensboro, Greensboro, North Carolina, USA
| | - Anthony S Kulas
- Department of Kinesiology, East Carolina University, Greenville, North Carolina, USA
| | - Jeffrey D Labban
- HHS Office of Research, University of North Carolina Greensboro, Greensboro, North Carolina, USA
| | - Hsin-Min Wang
- Department of Sports, National Changhua University of Education, Changhua, Taiwan
| |
Collapse
|
11
|
Nédélec E, Foli E, Shultz SJ, Swinton PA, Dolan E, Enright K, Piasecki J, Matthews JJ, Sale C, Elliott-Sale KJ. Effect of menstrual cycle phase, menstrual irregularities and hormonal contraceptive use on anterior knee laxity and non-contact anterior cruciate ligament injury occurrence in women: a protocol for a systematic review and meta-analysis. BMJ Open Sport Exerc Med 2021; 7:e001170. [PMID: 34745647 PMCID: PMC8559120 DOI: 10.1136/bmjsem-2021-001170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2021] [Indexed: 11/16/2022] Open
Abstract
Exercising women report three to six times more ACL tears than men, which happen, in the majority of cases, with a non-contact mechanism. This sex disparity has, in part, been attributed to the differences in reproductive hormone profiles between men and women. Many studies have shown that anterior knee (AK) laxity and the rate of non-contact ACL injuries vary across the menstrual cycle, but these data are inconsistent. Similarly, several studies have investigated the potential protective effect of hormonal contraceptives on non-contact ACL injuries, but their conclusions are also variable. The purpose of this systematic review and meta-analysis is to, identify, evaluate and summarise the effects of endogenous and exogenous ovarian hormones on AK laxity (primary outcome) and the occurrence of non-contact ACL injuries (secondary outcome) in women. We will perform a systematic search for all observational studies conducted on this topic. Studies will be retrieved by searching electronic databases, clinical trial registers, author's personal files and cross-referencing selected studies. Risk of bias will be assessed using the Newcastle Ottawa Quality Assessment Scale for Cohort and Case-Control Studies. Certainty in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. The meta-analyses will use a Bayesian approach to address specific research questions in a more intuitive and probabilistic manner. This review is registered on the international database of prospectively registered systematic reviews (PROSPERO; CRD42021252365).
Collapse
Affiliation(s)
- Elisa Nédélec
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Elvis Foli
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Paul A Swinton
- School of Health Sciences, Robert Gordon University, Aberdeen, UK
| | - Eimear Dolan
- Applied Physiology and Nutrition Research Group, Escola de Educação Física e Esporte, Faculdade de Medicina FMUSP, Universidade de São Paulo, Sao Paulo, Brazil
| | - Kevin Enright
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Jessica Piasecki
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Joseph J Matthews
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Craig Sale
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Kirsty Jayne Elliott-Sale
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement (SHAPE) Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| |
Collapse
|
12
|
Abstract
BACKGROUND Restricted ankle dorsiflexion range of motion (DFROM) has been linked to lower extremity biomechanics that place an athlete at higher risk for injury. Whether reduced DFROM during dynamic movements is due to restrictions in joint motion or underutilization of available ankle DFROM motion is unclear. HYPOTHESIS We hypothesized that both lesser total ankle DFROM and underutilization of available motion would lead to high-risk biomechanics (ie, greater knee abduction, reduced knee flexion). STUDY DESIGN Cross-sectional study. LEVEL OF EVIDENCE Level 3. METHODS Nineteen active female athletes (age, 20.0 ± 1.3 years; height, 1.61 ± 0.06 m; mass, 67.0 ± 10.7 kg) participated. Maximal ankle DFROM (clinical measure of ankle DFROM [DF-CLIN]) was measured in a weightbearing position with the knee flexed. Lower extremity biomechanics were measured during a drop vertical jump with 3-dimensional motion and force plate analysis. The percent of available DFROM used during landing (DF-%USED) was calculated as the peak DFROM observed during landing divided by DF-CLIN. Univariate linear regressions were performed to identify whether DF-CLIN or DF-%USED predicted knee and hip biomechanics commonly associated with injury risk. RESULTS For every 1.0° less of DF-CLIN, there was a 1.0° decrease in hip flexion excursion (r2 = 0.21, P = 0.05), 1.2° decrease in peak knee flexion angles (r2 = 0.37, P = 0.01), 0.9° decrease in knee flexion excursion (r2 = 0.40, P = 0.004), 0.002 N·m·N-1·cm-1 decrease in hip extensor work (r2 = 0.28, P = 0.02), and 0.001 N·m·N-1·cm-1 decrease in knee extensor work (r2 = 0.21, P = 0.05). For every 10% less of DF-%USED, there was a 3.2° increase in peak knee abduction angles (r2 = 0.26, P = 0.03) and 0.01 N·m·N-1·cm-1 lesser knee extensor work (r2 = 0.25, P = 0.03). CONCLUSION Lower levels of both ankle DFROM and DF-%USED are associated with biomechanics that are considered to be associated with a higher risk of sustaining injury. CLINICAL RELEVANCE While total ankle DFROM can predict some aberrant movement patterns, underutilization of available ankle DFROM can also lead to higher risk movement strategies. In addition to joint specific mobility training, clinicians should incorporate biomechanical interventions and technique feedback to promote the utilization of available motion.
Collapse
Affiliation(s)
- Jeffrey B Taylor
- Department of Physical Therapy, High Point University, High Point, North Carolina
| | - Elena S Wright
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina.,Department of Implementation Science, Division of Public Health Science, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Center for Healthcare Innovation, Wake Forest Baptist Health, Winston Salem, North Carolina
| | - Justin P Waxman
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Randy J Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - James D Groves
- Department of Physical Therapy, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina
| |
Collapse
|
13
|
Wang HM, Shultz SJ, Ross SE, Henson RA, Perrin DH, Schmitz RJ. Relationship of Anterior Cruciate Ligament Volume and T2* Relaxation Time to Anterior Knee Laxity. Orthop J Sports Med 2021; 9:2325967120979986. [PMID: 33718498 PMCID: PMC7925955 DOI: 10.1177/2325967120979986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 08/04/2020] [Indexed: 12/15/2022] Open
Abstract
Background: High anterior knee laxity (AKL) has been prospectively identified as a risk factor for anterior cruciate ligament (ACL) injuries. Given that ACL morphometry and structural composition have the potential to influence ligamentous strength, understanding how these factors are associated with greater AKL is warranted. Hypothesis: Smaller ACL volumes combined with longer T2* relaxation times would collectively predict greater AKL. Study Design: Cross-sectional study; Level of evidence, 3. Methods: College-aged active male (n = 20) and female (n = 30) participants underwent magnetic resonance imaging (MRI) and AKL testing. T2-weighted MRI scans were used to assess ACL volumes, and T2* relaxation times were used to assess ACL structural composition. AKL was measured via a commercial knee arthrometer. Forward stepwise linear regression with sex and weight (first step; suppressor variables) as well as ACL volume and T2* relaxation time (second step; independent variables) was used to predict AKL (dependent variable). Results: After initially adjusting for sex and weight (R2 = 0.19; P = .006), smaller ACL volumes combined with longer T2* relaxation times collectively predicted greater AKL (R2 = 0.52; P < .001; R2Δ = 0.32; PΔ < .001). A smaller ACL volume was the primary predictor of greater AKL (R2Δ = 0.28; P < .001), with a longer T2* relaxation time trending toward a significant contribution to greater AKL (R2Δ = 0.04; P = .062). After adjusting for ACL volume and T2* relaxation time, sex (partial r = 0.05; P = .735) and weight (partial r = 0.05; P = .725) were no longer significant predictors. Conclusion: AKL was largely predicted by ACL volume and to a lesser extent by T2* relaxation time (and not a person’s sex and weight). These findings enhance our understanding of how AKL may be associated with a structurally weaker ACL. The current study presents initial evidence that AKL is a cost-effective and clinically accessible measure that shows us something about the structural composition of the ACL. As AKL has been consistently shown to be a risk factor for ACL injuries, work should be done to continue to investigate what AKL may tell a clinician about the structure and composition of the ACL.
Collapse
Affiliation(s)
- Hsin-Min Wang
- Department of Sports, National Changhua University of Education, Changhua City, Taiwan
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Scott E Ross
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Robert A Henson
- Department of Educational Research Methodology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - David H Perrin
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah, USA
| | - Randy J Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| |
Collapse
|
14
|
Shultz SJ, Valovich McLeod TC. The Growing Influence of Female Athletic Training Scholars. J Athl Train 2021; 56:219. [PMID: 33618360 DOI: 10.4085/1062-6050-1003-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
15
|
Mulrey CR, Shultz SJ, Ford KR, Nguyen AD, Taylor JB. Methods of Identifying Limb Dominance in Adolescent Female Basketball Players: Implications for Clinical and Biomechanical Research. Clin J Sport Med 2020; 30:279-281. [PMID: 32341293 DOI: 10.1097/jsm.0000000000000589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To identify relationships between self-reported limb preferences and performance measures for determining limb dominance in adolescent female basketball players. DESIGN Cross-sectional cohort study. PARTICIPANTS Forty adolescent female basketball players. INDEPENDENT VARIABLES AND MAIN OUTCOME MEASURES Participants provided self-reported preferred kicking and jumping limbs, then completed 3 trials of a single-limb countermovement hop (HOPVER) and unilateral triple hop for distance (HOPHOR) on each limb. Each test was used to independently define limb dominance by the limb that produced the largest maximum vertical height and horizontal distance, respectively. RESULTS Chi-square tests for independence identified a significant relationship between self-reported preferred kicking and jumping legs (χ = 7.41, P = 0.006). However, no significant relationships were found when comparing self-reported preference to measures of performance during the HOPHOR (χ = 0.33, P = 0.57) or HOPVER (χ = 0.06, P = 0.80). In addition, the 2 performance measures did not consistently produce the same definition of limb dominance among individuals (χ = 1.52, P = 0.22). CONCLUSIONS Self-selection of the dominant limb is unrelated to performance. Furthermore, limb dominance, as defined by vertical jump height, is unrelated to limb dominance defined by horizontal jump distance. The results of this study call into question the validity of consistently defining limb dominance by self-reported measures in adolescent female basketball players.
Collapse
Affiliation(s)
- Colleen R Mulrey
- Department of Exercise Science, Congdon School of Health Sciences, High Point University, High Point, North Carolina
| | - Sandra J Shultz
- Department of Kinesiology, School of Health and Human Sciences, University of North Carolina at Greensboro, Greensboro, North Carolina; and
| | | | - Anh-Dung Nguyen
- Athletic Training, Congdon School of Health Sciences, High Point University, High Point, North Carolina
| | | |
Collapse
|
16
|
Taylor JB, Nguyen AD, Shultz SJ, Ford KR. Hip biomechanics differ in responders and non-responders to an ACL injury prevention program. Knee Surg Sports Traumatol Arthrosc 2020; 28:1236-1245. [PMID: 30259145 DOI: 10.1007/s00167-018-5158-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 09/17/2018] [Indexed: 01/14/2023]
Abstract
PURPOSE To investigate the differences in demographic, anthropometric, biomechanical, and/or performance variables between those that do (responders) and do not (non-responders) exhibit reductions in knee abduction moments after an anterior cruciate ligament injury prevention program (ACL-IPP). METHODS Forty-three adolescent female athletes completed biomechanical (3D motion analysis of a drop vertical jump) and performance testing before and after randomization into a 6-week ACL-IPP. Participants were classified into responders and non-responders based on their level of reduction of knee abduction moment from pre- to post-test. RESULTS Compared to non-responders, responders exhibited increased hip adduction excursion at baseline (p = 0.02) and trended towards attending more training sessions (p = 0.07) and participating in soccer and not basketball (p = 0.07). Responders also showed greater improvements in hip flexion angles (p = 0.02) and moments (p < 0.001), and knee abduction angles (p < 0.001) and excursions (p = 0.001). There were no significant differences in age or experience with prior injury prevention programs (n.s.). CONCLUSIONS After an ACL-IPP, athletes that exhibit the greatest reduction in knee abduction moments exhibit greater hip adduction excursion at baseline and show corresponding improvements in hip flexion and knee abduction kinematics and hip flexion moments. These results can help clinicians prospectively identify individuals that may not respond to an ACL-IPP and target individualized training for those at risk of injury. LEVEL OF EVIDENCE I. CLINICAL TRIAL REGISTRATION NUMBER Clinicaltrials.gov NCT02530333.
Collapse
Affiliation(s)
- Jeffrey B Taylor
- Department of Physical Therapy, Congdon School of Health Sciences, High Point University, One University Parkway, High Point, NC, 27268, USA. .,Department of Kinesiology, School of Health and Human Sciences, University of North Carolina at Greensboro, Greensboro, NC, USA.
| | - Anh-Dung Nguyen
- Department of Athletic Training, Congdon School of Health Sciences, High Point University, High Point, NC, USA
| | - Sandra J Shultz
- Department of Kinesiology, School of Health and Human Sciences, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Kevin R Ford
- Department of Physical Therapy, Congdon School of Health Sciences, High Point University, One University Parkway, High Point, NC, 27268, USA
| |
Collapse
|
17
|
Wang HM, Shultz SJ, Ross SE, Henson RA, Perrin DH, Schmitz RJ. ACL Size and Notch Width Between ACLR and Healthy Individuals: A Pilot Study. Sports Health 2019; 12:61-65. [PMID: 31526322 DOI: 10.1177/1941738119873631] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Given the relatively high risk of contralateral anterior cruciate ligament (ACL) injury in patients with ACL reconstruction (ACLR), there is a need to understand intrinsic risk factors that may contribute to contralateral injury. HYPOTHESIS The ACLR group would have smaller ACL volume and a narrower femoral notch width than healthy individuals after accounting for relevant anthropometrics. STUDY DESIGN Cross-sectional study. LEVEL OF EVIDENCE Level 3. METHODS Magnetic resonance imaging data of the left knee were obtained from uninjured (N = 11) and unilateral ACL-reconstructed (N = 10) active, female, collegiate-level recreational athletes. ACL volume was obtained from T2-weighted images. Femoral notch width and notch width index were measured from T1-weighted images. Independent-samples t tests examined differences in all measures between healthy and ACLR participants. RESULTS The ACLR group had a smaller notch width index (0.22 ± 0.02 vs 0.25 ± 0.01; P = 0.004; effect size, 1.41) and ACL volume (25.6 ± 4.0 vs 32.6 ± 8.2 mm3/(kg·m)-1; P = 0.025; effect size, 1.08) after normalizing by body size. CONCLUSION Only after normalizing for relevant anthropometrics, the contralateral ACLR limb had smaller ACL size and narrower relative femoral notch size than healthy individuals. These findings suggest that risk factor studies of ACL size and femoral notch size should account for relevant body size when determining their association with contralateral ACL injury. CLINICAL RELEVANCE The present study shows that the method of the identified intrinsic risk factors for contralateral ACL injury could be used in future clinical screening settings.
Collapse
Affiliation(s)
- Hsin-Min Wang
- Department of Sports, National Changhua University of Education, Changhua City, Taiwan
| | - Sandra J Shultz
- Department of Kinesiology & Gateway MRI Center, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Scott E Ross
- Department of Kinesiology & Gateway MRI Center, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Robert A Henson
- Department of Educational Research Methodology, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - David H Perrin
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah
| | - Randy J Schmitz
- Department of Kinesiology & Gateway MRI Center, University of North Carolina at Greensboro, Greensboro, North Carolina
| |
Collapse
|
18
|
Shultz SJ, Schmitz RJ, Cameron KL, Ford KR, Grooms DR, Lepley LK, Myer GD, Pietrosimone B. Anterior Cruciate Ligament Research Retreat VIII Summary Statement: An Update on Injury Risk Identification and Prevention Across the Anterior Cruciate Ligament Injury Continuum, March 14-16, 2019, Greensboro, NC. J Athl Train 2019; 54:970-984. [PMID: 31461312 PMCID: PMC6795093 DOI: 10.4085/1062-6050-54.084] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Sandra J. Shultz
- Applied Neuromechanics Research Laboratory, University of North Carolina at Greensboro
| | - Randy J. Schmitz
- Applied Neuromechanics Research Laboratory, University of North Carolina at Greensboro
| | - Kenneth L. Cameron
- John A. Feagin Jr Sports Medicine Fellowship, Keller Army Hospital, United States Military Academy, West Point, NY
| | - Kevin R. Ford
- Human Biomechanics and Physiology Laboratory, Department of Physical Therapy, High Point University, NC
| | - Dustin R. Grooms
- Ohio Musculoskeletal & Neurological Institute and Division of Athletic Training, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Athens
| | | | - Gregory D. Myer
- The SPORT Center, Division of Sports Medicine, and Departments of Pediatrics and Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, College of Medicine, University of Cincinnati, OH
| | - Brian Pietrosimone
- MOTION Science Institute, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill
| |
Collapse
|
19
|
Anderson T, Wasserman EB, Shultz SJ. Anterior Cruciate Ligament Injury Risk by Season Period and Competition Segment: An Analysis of National Collegiate Athletic Association Injury Surveillance Data. J Athl Train 2019; 54:787-795. [PMID: 31322904 DOI: 10.4085/1062-6050-501-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Although fatigue has been implicated in anterior cruciate ligament (ACL) injury, few researchers have examined the timing of injury across a competitive sport season or within a competitive session to gain insight into the potential effects of fatigue on the incidence of ACL injury. OBJECTIVE To identify the time segments across a competitive season or within an individual competition associated with the greatest ACL injury incidence. DESIGN Descriptive epidemiology study. METHODS Data from the National Collegiate Athletic Association Injury Surveillance Program for 2004-2005 through 2015-2016 for basketball, lacrosse, and soccer were analyzed. Incidence rate ratios (IRRs) compared ACL injury rates by sport, sex, season segment, and competition period. Poisson regression was used to examine the associations between each of these categories and the incidence of ACL injury as well as interaction effects. RESULTS During the early regular season, the incidence rate was elevated relative to the preseason (IRR = 1.86; 95% confidence interval [CI] = 1.27, 2.74), middle regular season (IRR = 1.48; 95% CI = 1.01, 2.15), late regular season (IRR = 1.56; 95% CI = 1.08, 2.27), and postseason (IRR = 2.20; 95% CI = 1.06, 4.56). A sport-by-season interaction indicated this effect was largely attributable to a higher incidence in the early season among lacrosse athletes. An interaction between season segment and competition period (P = .02) revealed a greater injury incidence before halftime in the early regular season (IRR = 0.38, 95% CI = 0.19, 0.76), but a greater incidence after halftime in the late regular season (IRR = 2.40, 95% CI = 1.15, 5.02). Fewer noncontact injuries occurred in soccer than in basketball or lacrosse. CONCLUSIONS The ACL injury incidence was higher in the early part of the regular season, particularly among lacrosse athletes. Although the injury incidences before and after halftime were similar, further analyses of player time and time of injury within each half are necessary. Coaches and practitioners should be cognizant of the elevated injury incidence during the early season among lacrosse athletes. Future authors should consider more specific analyses to further elucidate the potential role of fatigue development in exacerbating the incidence of ACL injury in collegiate athletes both within games and across the season.
Collapse
Affiliation(s)
- Travis Anderson
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Erin B Wasserman
- Datalys Center for Sports Injury Research and Prevention, Inc, Indianapolis, IN
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro
| |
Collapse
|
20
|
Abstract
CONTEXT Females have consistently higher anterior cruciate ligament (ACL) injury rates than males. The reasons for this disparity are not fully understood. Whereas ACL morphometric characteristics are associated with injury risk and females have a smaller absolute ACL size, comprehensive sex comparisons that adequately account for sex differences in body mass index (BMI) have been limited. OBJECTIVE To investigate sex differences among in vivo ACL morphometric measures before and after controlling for femoral notch width and BMI. DESIGN Cross-sectional study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty recreationally active men (age = 23.2 ± 2.9 years, height = 180.4 ± 6.7 cm, mass = 84.0 ± 10.9 kg) and 20 recreationally active women (age = 21.3 ± 2.3 years, height = 166.9 ± 7.7 cm, mass = 61.9 ± 7.2 kg) participated. MAIN OUTCOME MEASURE(S) Structural magnetic resonance imaging sequences were performed on the left knee. Anterior cruciate ligament volume, width, and cross-sectional area measures were obtained from T2-weighted images and normalized to femoral notch width and BMI. Femoral notch width was measured from T1-weighted images. We used independent-samples t tests to examine sex differences in absolute and normalized measures. RESULTS Men had greater absolute ACL volume (1712.2 ± 356.3 versus 1200.1 ± 337.8 mm3; t38 = -4.67, P < .001) and ACL width (8.5 ± 2.3 versus 7.0 ± 1.2 mm; t38 = -2.53, P = .02) than women. The ACL volume remained greater in men than in women after controlling for femoral notch width (89.31 ± 15.63 versus 72.42 ± 16.82 mm3/mm; t38 = -3.29, P = .002) and BMI (67.13 ± 15.40 versus 54.69 ± 16.39 mm3/kg/m2; t38 = -2.47, P = .02). CONCLUSIONS Whereas men had greater ACL volume and width than women, only ACL volume remained different when we accounted for femoral notch width and BMI. This suggests that ACL volume may be an appropriate measure of ACL anatomy in investigations of ACL morphometry and ACL injury risk that include sex comparisons.
Collapse
Affiliation(s)
- Hsin-Min Wang
- Department of Sports, National Changhua University of Education, Taiwan
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Scott E Ross
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Robert A Henson
- Department of Educational Research Methodology, University of North Carolina at Greensboro
| | - David H Perrin
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City
| | - Robert A Kraft
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Randy J Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro
| |
Collapse
|
21
|
Taylor JB, Ford KR, Schmitz RJ, Ross SE, Ackerman TA, Shultz SJ. A 6-week warm-up injury prevention programme results in minimal biomechanical changes during jump landings: a randomized controlled trial. Knee Surg Sports Traumatol Arthrosc 2018; 26:2942-2951. [PMID: 29340745 DOI: 10.1007/s00167-018-4835-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 01/08/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE To examine the extent to which an ACL injury prevention programme modifies lower extremity biomechanics during single- and double-leg landing tasks in both the sagittal and frontal plane. It was hypothesized that the training programme would elicit improvements in lower extremity biomechanics, but that these improvements would be greater during a double-leg sagittal plane landing task than tasks performed on a single leg or in the frontal plane. METHODS Ninety-seven competitive multi-directional sport athletes that competed at the middle- or high-school level were cluster randomized into intervention (n = 48, age = 15.4 ± 1.0 years, height = 1.7 ± 0.07 m, mass = 59.9 ± 11.0 kg) and control (n = 49, age = 15.7 ± 1.6 years, height = 1.7 ± 0.06 m, mass = 60.4 ± 7.7 kg) groups. The intervention group participated in an established 6-week warm-up-based ACL injury prevention programme. Three-dimensional biomechanical analyses of a double- (SAG-DL) and single-leg (SAG-SL) sagittal, and double- (FRONT-DL) and single-leg (FRONT-SL) frontal plane jump landing tasks were tested before and after the intervention. Peak angles, excursions, and external joint moments were analysed for group differences using 2 (group) × 4 (task) repeated measures MANOVA models of delta scores (post-pre-test value) (α < 0.05). RESULTS Relative to the control group, no significant biomechanical changes were identified in the intervention group for any of the tasks (n.s.). However, a group by task interaction was identified for knee abduction (λ = 0.80, p = 0.02), such that participants in the intervention group showed relative decreases in knee abduction moments during the SAG-DL compared to the SAG-SL (p = 0.005; d = 0.45, CI = 0.04-0.85) task. CONCLUSION A 6-week warm-up-based ACL injury prevention programme resulted in no significant biomechanical changes during a variety of multi-directional jump landings. Clinically, future prevention programmes should provide a greater training stimulus (intensity, volume), more specificity to tasks associated with the mechanism of ACL injury (single-leg, non-sagittal plane jump landings), and longer programme duration (> 6 weeks) to elicit meaningful biomechanical changes. LEVEL OF EVIDENCE I.
Collapse
Affiliation(s)
- Jeffrey B Taylor
- Department of Physical Therapy, High Point University, One University Parkway, High Point, NC, 27268, USA. .,Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA.
| | - Kevin R Ford
- Department of Physical Therapy, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Randy J Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Scott E Ross
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | | | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA
| |
Collapse
|
22
|
Abstract
CONTEXT Greater passive hip range of motion (ROM) has been associated with greater dynamic knee valgus and thus the potential for increased risk of anterior cruciate ligament injuries. Normative data for passive hip ROM by sex are lacking. OBJECTIVE To establish and compare passive hip ROM values by sex and sport and to quantify side-to-side differences in internal-rotation ROM (ROMIR), external-rotation ROM (ROMER), and total ROM (ROMTOT). DESIGN Cross-sectional study. SETTING Station-based, preparticipation screening. PATIENTS OR OTHER PARTICIPANTS A total of 339 National Collegiate Athletic Association Division I athletes, consisting of 168 women (age = 19.2 ± 1.2 years, height = 169.0 ± 7.2 cm, mass = 65.3 ± 10.2 kg) and 171 men (age = 19.4 ± 1.3 years, height = 200.0 ± 8.6 cm, mass = 78.4 ± 12.0 kg) in 6 sports screened over 3 years: soccer (58 women, 67 men), tennis (20 women, 22 men), basketball (28 women, 22 men), softball or baseball (38 women, 31 men), cross-country (18 women, 19 men), and golf (6 women, 10 men). MAIN OUTCOME MEASURE(S) Passive hip ROM was measured with the athlete lying prone with the hip abducted to 20° to 30° and knee flexed to 90°. The leg was passively internally and externally rotated until the point of sacral movement. Three measures were averaged for each direction and leg and used for analysis. We compared ROMIR, ROMER, ROMTOT (ROMTOT = ROMIR + ROMER), and relative ROM (ROMREL = ROMIR - ROMER) between sexes and among sports using separate 2 × 6 repeated-measures analyses of variance. RESULTS Women had greater ROMIR (38.1° ± 8.2° versus 28.6° ± 8.4°; F1,327 = 91.74, P < .001), ROMTOT (72.1° ± 10.6° versus 64.4° ± 10.1°; F1,327 = 33.47, P < .001), and ROMREL (1.5° ± 16.0° versus -7.6° ± 16.5°; F1,327 = 37.05, P < .001) than men but similar ROMER (34.0° ± 12.2° versus 35.8° ± 11.5°; F1,327 = 1.65, P = .20) to men. Cross-country athletes exhibited greater ROMIR (37.0° ± 9.3° versus 30.9° ± 9.4° to 33.3° ± 9.5°; P = .001) and ROMREL (5.9° ± 18.3° versus -9.6° ± 16.9° to -2.7° ± 17.3°; P = .001) and less ROMER (25.7° ± 7.5° versus 35.0° ± 13.0° to 40.2° ± 12.0°; P < .001) than basketball, soccer, softball or baseball, and tennis athletes. They also displayed less ROMTOT (62.7° ± 8.1° versus 70.0° ± 9.1° to 72.9° ± 11.9°; P < .001) than basketball, softball or baseball, and tennis athletes. CONCLUSIONS Women had greater ROMIR than men, resulting in greater ROMTOT and ROMREL. Researchers should examine the extent to which this greater bias toward ROMIR may explain women's greater tendency for dynamic knee valgus. With the exception of cross-country, ROM values were similar across sports. The clinical implications of these aberrant cross-country values require further study.
Collapse
|
23
|
Taylor JB, Ford KR, Schmitz RJ, Ross SE, Ackerman TA, Shultz SJ. Sport-specific biomechanical responses to an ACL injury prevention programme: A randomised controlled trial. J Sports Sci 2018; 36:2492-2501. [PMID: 29671383 DOI: 10.1080/02640414.2018.1465723] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Anterior cruciate ligament (ACL) injury prevention programmes have not been as successful at reducing injury rates in women's basketball as in soccer. This randomised controlled trial (ClinicalTrials.gov #NCT02530333) compared biomechanical adaptations in basketball and soccer players during jump-landing activities after an ACL injury prevention programme. Eighty-seven athletes were cluster randomised into intervention (6-week programme) and control groups. Three-dimensional biomechanical analyses of drop vertical jump (DVJ), double- (SAG-DL) and single-leg (SAG-SL) sagittal, and double- (FRONT-DL) and single-leg (FRONT-SL) frontal plane jump landing tasks were tested before and after the intervention. Peak angles, excursions, and joint moments were analysed using two-way MANCOVAs of post-test scores while controlling for pre-test scores. During SAG-SL the basketball intervention group exhibited increased peak knee abduction angles (p = .004) and excursions (p = .003) compared to the basketball control group (p = .01) and soccer intervention group (p = .01). During FRONT-SL, the basketball intervention group exhibited greater knee flexion excursion after training than the control group (p = .01), but not the soccer intervention group (p = .11). Although women's soccer players exhibit greater improvements in knee abduction kinematics than basketball players, these athletes largely exhibit similar biomechanical adaptations to ACL injury prevention programmes.
Collapse
Affiliation(s)
- Jeffrey B Taylor
- a Department of Physical Therapy , High Point University , High Point , NC , USA.,b Department of Kinesiology , University of North Carolina at Greensboro , Greensboro , NC , USA
| | - Kevin R Ford
- a Department of Physical Therapy , High Point University , High Point , NC , USA
| | - Randy J Schmitz
- b Department of Kinesiology , University of North Carolina at Greensboro , Greensboro , NC , USA
| | - Scott E Ross
- b Department of Kinesiology , University of North Carolina at Greensboro , Greensboro , NC , USA
| | | | - Sandra J Shultz
- b Department of Kinesiology , University of North Carolina at Greensboro , Greensboro , NC , USA
| |
Collapse
|
24
|
Taylor JB, Ford KR, Schmitz RJ, Ross SE, Ackerman TA, Shultz SJ. Biomechanical Differences of Multidirectional Jump Landings Among Female Basketball and Soccer Players. J Strength Cond Res 2018; 31:3034-3045. [PMID: 29065078 DOI: 10.1519/jsc.0000000000001785] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Taylor, JB, Ford, KR, Schmitz, RJ, Ross, SE, Ackerman, TA, and Shultz, SJ. Biomechanical differences of multidirectional jump landings among female basketball and soccer players. J Strength Cond Res 31(11): 3034-3045, 2017-Anterior cruciate ligament (ACL) injury prevention programs are less successful in basketball than soccer and may be due to distinct movement strategies that these athletes develop from sport-specific training. The purpose of this study was to identify biomechanical differences between female basketball and soccer players during multidirectional jump landings. Lower extremity biomechanics of 89 female athletes who played competitive basketball (n = 40) or soccer (n = 49) at the middle- or high-school level were analyzed with 3-dimensional motion analysis during a drop vertical jump, double- (SAG-DL) and single-leg forward jump (SAG-SL), and double- (FRONT-DL) and single-leg (FRONT-SL) lateral jump. Basketball players landed with either less hip or knee, or both hip and knee excursion during all tasks (p ≤ 0.05) except for the SAGSL task, basketball players landed with greater peak hip flexion angles (p = 0.04). The FRONT-SL task elicited the most distinct sport-specific differences, including decreased hip adduction (p < 0.001) angles, increased hip internal rotation (p = 0.003), and increased relative knee external rotation (p = 0.001) excursions in basketball players. In addition, the FRONT-SL task elicited greater forces in knee abduction (p = 0.003) and lesser forces in hip adduction (p = 0.001) and knee external rotation (p < 0.001) in basketball players. Joint energetics were different during the FRONT-DL task, as basketball players exhibited less sagittal plane energy absorption at the hip (p < 0.001) and greater hip (p < 0.001) and knee (p = 0.001) joint stiffness. Sport-specific movement strategies were identified during all jump landing tasks, such that soccer players exhibited a more protective landing strategy than basketball players, justifying future efforts toward sport-specific ACL injury prevention programs.
Collapse
Affiliation(s)
- Jeffrey B Taylor
- 1Department of Physical Therapy, High Point University, High Point, North Carolina; 2Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina; and 3Department of Educational Research Methodology, University of North Carolina at Greensboro, Greensboro, North Carolina
| | | | | | | | | | | |
Collapse
|
25
|
Kulas AS, Schmitz RJ, Shultz SJ, Waxman JP, Wang HM, Kraft RA, Partington HS. Bilateral quadriceps and hamstrings muscle volume asymmetries in healthy individuals. J Orthop Res 2018; 36:963-970. [PMID: 28755488 DOI: 10.1002/jor.23664] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 07/21/2017] [Indexed: 02/04/2023]
Abstract
Determining the magnitude of quadriceps and hamstring muscle volume asymmetries in healthy individuals is a critical first step toward interpreting asymmetries as compensatory or abnormal in pathological populations. The purpose of this study was to determine the magnitude of whole and individual muscle volume asymmetries, quantified as right-left volume differences, for the quadriceps and hamstring muscles in a young and healthy population. Twenty-one healthy individuals participated: Eleven females age = 22.6 ± 2.9 years and 10 males age = 23.2 ± 3.4 years. Whole muscle group and individual muscle volume asymmetries were quantified within the context of absolute measurement error using a 95% Limits of Agreement approach. Mean muscle asymmetries ranged from -3.0 to 6.0% for all individual and whole muscle groups. Whole muscle group 95% limits of agreements represented ±11.4% and ±8.8% volume asymmetries for the hamstrings and quadriceps, respectively. Individual muscle asymmetry 95% limits of agreements ranged from ∼ ± 11-13% for the vastii muscles while the biceps femoris short-head (±33.5%), long-head (±20.9%), and the rectus femoris (±21.4%) displayed the highest relative individual asymmetries. Individual muscle asymmetries exceeded absolute measurement error in 70% of all cases, with 26% of all cases exceeding 10% asymmetry. Although whole muscle group asymmetries appear to be near the 10% assumed clinical threshold of normality, the greater magnitude of individual muscle asymmetries highlights the subject- and muscle-specific variability in volume asymmetry. Future research is warranted to determine if volume asymmetry thresholds exist that discriminate between healthy and pathological populations. Statement of Clinical Significance: Muscle volume asymmetries displayed in healthy individuals provide a reference for interpreting asymmetries in pathological populations. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:963-970, 2018.
Collapse
Affiliation(s)
| | - Randy J Schmitz
- The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Sandra J Shultz
- The University of North Carolina at Greensboro, Greensboro, North Carolina
| | | | | | | | - Heath S Partington
- The University of North Carolina at Greensboro, Greensboro, North Carolina
| |
Collapse
|
26
|
Abstract
CONTEXT Understanding the factors associated with thicker cartilage in a healthy population is important when developing strategies aimed at minimizing the cartilage thinning associated with knee osteoarthritis progression. Thicker articular cartilage is commonly thought to be healthier cartilage, but whether the sagittal-plane biomechanics important to gait are related to cartilage thickness is unknown. OBJECTIVE To determine the relationship of a weight-bearing region of the medial femoral condyle's cartilage thickness to sagittal gait biomechanics in healthy individuals. DESIGN Descriptive laboratory study. SETTING Laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty-eight healthy participants (15 women: age = 21.1 ± 2.1 years, height = 1.63 ± 0.07 m, weight = 64.6 ± 9.9 kg; 13 men: age = 22.1 ± 2.9 years, height = 1.79 ± 0.05 m, weight = 75.2 ± 9.6 kg). MAIN OUTCOME MEASURE(S) Tibiofemoral angle (°) was obtained via goniometric assessment, thickness of the medial femoral condyle cartilage (mm) was obtained via ultrasound imaging, and peak internal knee-extensor moment (% body weight · height) was measured during 10 trials of over-ground walking at a self-selected pace. We used linear regression to examine the extent to which peak internal knee-extensor moment predicted cartilage thickness after accounting for tibiofemoral angle and sex. RESULTS Sex and tibiofemoral angle (12.3° ± 3.2°) were entered in the initial step as control factors (R2 = 0.01, P = .872). In the final step, internal knee-extensor moment (1.5% ± 1.3% body weight · height) was entered, which resulted in greater knee-extensor moment being related to greater cartilage thickness (2.0 ± 0.3 mm; R2Δ = 0.31, PΔ = .003). CONCLUSION Individuals who walked with a greater peak internal knee-extensor moment during gait had a cartilage structure that is generally considered beneficial in a healthy population. Our study offers promising findings that a potentially modifiable biomechanical factor is associated with cartilage status in a healthy population. Establishing these baseline relationships in uninjured populations may help us to better understand potential factors related to maladaptive gait patterns that predispose a person to adverse changes in the cartilage environment.
Collapse
Affiliation(s)
- Randy J Schmitz
- Department of Kinesiology, University of North Carolina-Greensboro
| | - David Harrison
- Department of Kinesiology, University of North Carolina-Greensboro
| | - Hsin-Min Wang
- Department of Sports Medicine, China Medical University, Taiwan
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina-Greensboro
| |
Collapse
|
27
|
Padua DA, DiStefano LJ, Hewett TE, Garrett WE, Marshall SW, Golden GM, Shultz SJ, Sigward SM. National Athletic Trainers' Association Position Statement: Prevention of Anterior Cruciate Ligament Injury. J Athl Train 2018; 53:5-19. [PMID: 29314903 DOI: 10.4085/1062-6050-99-16] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To provide certified athletic trainers, physicians, and other health care and fitness professionals with recommendations based on current evidence regarding the prevention of noncontact and indirect-contact anterior cruciate ligament (ACL) injuries in athletes and physically active individuals. BACKGROUND Preventing ACL injuries during sport and physical activity may dramatically decrease medical costs and long-term disability. Implementing ACL injury-prevention training programs may improve an individual's neuromuscular control and lower extremity biomechanics and thereby reduce the risk of injury. Recent evidence indicates that ACL injuries may be prevented through the use of multicomponent neuromuscular-training programs. RECOMMENDATIONS Multicomponent injury-prevention training programs are recommended for reducing noncontact and indirect-contact ACL injuries and strongly recommended for reducing noncontact and indirect-contact knee injuries during physical activity. These programs are advocated for improving balance, lower extremity biomechanics, muscle activation, functional performance, strength, and power, as well as decreasing landing impact forces. A multicomponent injury-prevention training program should, at minimum, provide feedback on movement technique in at least 3 of the following exercise categories: strength, plyometrics, agility, balance, and flexibility. Further guidance on training dosage, intensity, and implementation recommendations is offered in this statement.
Collapse
|
28
|
Montgomery MM, Tritsch AJ, Cone JR, Schmitz RJ, Henson RA, Shultz SJ. The Influence of Lower Extremity Lean Mass on Landing Biomechanics During Prolonged Exercise. J Athl Train 2017; 52:738-746. [PMID: 28722467 PMCID: PMC5561774 DOI: 10.4085/1062-6050-52.5.03] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT The extent to which lower extremity lean mass (LELM) relative to total body mass influences one's ability to maintain safe landing biomechanics during prolonged exercise when injury incidence increases is unknown. OBJECTIVES To examine the influence of LELM on (1) pre-exercise lower extremity biomechanics and (2) changes in biomechanics during an intermittent exercise protocol (IEP) and (3) determine whether these relationships differ by sex. We hypothesized that less LELM would predict higher-risk baseline biomechanics and greater changes toward higher-risk biomechanics during the IEP. DESIGN Cohort study. SETTING Controlled laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 59 athletes (30 men: age = 20.3 ± 2.0 years, height = 1.79 ± 0.05 m, mass = 75.2 ± 7.2 kg; 29 women: age = 20.6 ± 2.3 years, height = 1.67 ± 0.08 m, mass = 61.8 ± 9.0 kg) participated. INTERVENTION(S) Before completing an individualized 90-minute IEP designed to mimic a soccer match, participants underwent dual-energy x-ray absorptiometry testing for LELM. MAIN OUTCOME MEASURE(S) Three-dimensional lower extremity biomechanics were measured during drop-jump landings before the IEP and every 15 minutes thereafter. A previously reported principal components analysis reduced 40 biomechanical variables to 11 factors. Hierarchical linear modeling analysis then determined the extent to which sex and LELM predicted the baseline score and the change in each factor over time. RESULTS Lower extremity lean mass did not influence baseline biomechanics or the changes over time. Sex influenced the biomechanical factor representing knee loading at baseline (P = .04) and the changes in the anterior cruciate ligament-loading factor over time (P = .03). The LELM had an additional influence only on women who possessed less LELM (P = .03 and .02, respectively). CONCLUSIONS Lower extremity lean mass influenced knee loading during landing in women but not in men. The effect appeared to be stronger in women with less LELM. Continually decreasing knee loading over time may reflect a strategy chosen to avoid injury. A minimal threshold of LELM may be needed to safely perform landing maneuvers, especially during prolonged exercise when the injury risk increases.
Collapse
Affiliation(s)
- Melissa M Montgomery
- Center for Sport Performance, Department of Kinesiology, California State University, Fullerton
| | | | - John R Cone
- Athletes Research Institute Inc, Chapel Hill, NC
| | - Randy J Schmitz
- Department of §Kinesiology, University of North Carolina at Greensboro
| | - Robert A Henson
- ||Department of Educational Research Methodology, University of North Carolina at Greensboro
| | - Sandra J Shultz
- Department of §Kinesiology, University of North Carolina at Greensboro
| |
Collapse
|
29
|
Anderson T, Kincaid Z, Wideman L, Shultz SJ. Relaxin Influences Knee Laxity Changes Across the Menstrual Cycle. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000518799.14205.44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
30
|
Abstract
CONTEXT Greater anterior knee laxity (AKL) has been identified as an anterior cruciate ligament (ACL) injury risk factor. The structural factors that contribute to greater AKL are not fully understood but may include the ACL and bone geometry. OBJECTIVE To determine the relationship of ACL width and femoral notch angle to AKL. DESIGN Cross-sectional study. SETTING Controlled laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty recreationally active females (age = 21.2 ± 3.1 years, height = 1.66.1 ± 7.3 cm, mass = 66.5 ± 12.0 kg). MAIN OUTCOME MEASURE(S) Anterior cruciate ligament width and femoral notch angle were obtained with magnetic resonance imaging of the knee and AKL was assessed. Anterior cruciate ligament width was measured as the width of a line that transected the ACL and was drawn perpendicular to the Blumensaat line. Femoral notch angle was formed by the intersection of the line parallel to the posterior cortex of the femur and the Blumensaat line. Anterior knee laxity was the anterior displacement of the tibia relative to the femur (mm) at 130 N of an applied force. Ten participants' magnetic resonance imaging data were assessed on 2 occasions to establish intratester reliability and precision. Using stepwise backward linear regression, we examined the extent to which ACL width, femoral notch angle, and weight were associated with AKL. RESULTS Strong measurement consistency and precision (intraclass correlation coefficient [2,1] ± SEM) were established for ACL width (0.98 ± 0.3 mm) and femoral notch angle (0.97° ± 1.1°). The regression demonstrated that ACL width (5.9 ± 1.4 mm) was negatively associated with AKL (7.2 ± 2.0 mm; R(2) = 0.22, P = .04). Femoral notch angle and weight were not retained in the final model. CONCLUSIONS A narrower ACL was associated with greater AKL. This finding may inform the development of ACL injury-prevention programs that include components designed to increase ACL size or strength (or both). Future authors should establish which other factors contribute to greater AKL in order to best inform injury-prevention efforts.
Collapse
Affiliation(s)
- Hsin-Min Wang
- Department of Sports Medicine, China Medical University, Taiwan
| | - Sandra J Shultz
- Department of Kinesiology, Applied Neuromechanics Research Laboratory, The University of North Carolina at Greensboro
| | - Randy J Schmitz
- Department of Kinesiology, Applied Neuromechanics Research Laboratory, The University of North Carolina at Greensboro
| |
Collapse
|
31
|
Abstract
BACKGROUND Double-leg forward or drop-jump landing activities are typically used to screen for high-risk movement strategies and to determine the success of neuromuscular injury prevention programs. However, research suggests that these tasks that occur primarily in the sagittal plane may not adequately represent the lower extremity biomechanics that occur during unilateral foot contact or non-sagittal plane movements that are characteristic of many multidirectional sports. PURPOSE To examine the extent to which lower extremity biomechanics measured during a jump landing on a double leg (DL) after a sagittal plane (SAG) movement is representative of biomechanics measured during single-leg (SL) or frontal plane (FRONT) jump landing tasks. STUDY DESIGN Controlled laboratory study. METHODS Lower extremity biomechanics were measured in 15 recreationally active females (mean age [±SD], 19.4 ± 2.1 years; mean height, 163.3 ± 5.9 cm; mean weight, 61.1 ± 7.1 kg) while performing SAGDL, SAGSL, FRONTDL, and FRONTSL jump landing tasks. Repeated-measures analyses of variance examined differences in lower extremity biomechanics between the 4 tasks, and linear regressions examined the extent to which an individual's biomechanics during SAGDL were representative of their biomechanics during SAGSL, FRONTDL, and FRONTSL. RESULTS Lower extremity kinematics and kinetics differed by condition, with the SAGDL task generally eliciting greater hip and knee flexion angles and lower hip and knee forces than the other tasks (P < .05). Although biomechanics during the SAGDL task were strongly associated with those during the FRONTDL task (R (2), 0.41-0.82), weaker associations were observed between SAGDL and single-leg tasks for hip kinematics (R (2), 0.03-0.25) and kinetics (R (2), 0.05-0.20) and knee abduction moments (R (2), 0.06-0.18) (P < .05). CONCLUSION Standard double-leg sagittal plane jump landing tasks used to screen for ACL injury risk and the effectiveness of ACL injury prevention programs may not adequately represent the lower extremity biomechanics that occur during single-leg activities. CLINICAL RELEVANCE These results support further investigation of single-leg multidirectional landings to identify high-risk movement strategies in female athletes playing multidirectional sports.
Collapse
Affiliation(s)
- Jeffrey B Taylor
- Department of Physical Therapy, High Point University, High Point, North Carolina, USA.; Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Kevin R Ford
- Department of Physical Therapy, High Point University, High Point, North Carolina, USA
| | - Anh-Dung Nguyen
- Department of Athletic Training, High Point University, High Point, North Carolina, USA
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| |
Collapse
|
32
|
Vacek PM, Slauterbeck JR, Tourville TW, Sturnick DR, Holterman LA, Smith HC, Shultz SJ, Johnson RJ, Tourville KJ, Beynnon BD. Multivariate Analysis of the Risk Factors for First-Time Noncontact ACL Injury in High School and College Athletes: A Prospective Cohort Study With a Nested, Matched Case-Control Analysis. Am J Sports Med 2016; 44:1492-501. [PMID: 27217522 PMCID: PMC6533630 DOI: 10.1177/0363546516634682] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Multivariate analysis that identifies the combination of risk factors associated with anterior cruciate ligament (ACL) trauma is important because it provides insight into whether a variable has a direct causal effect on risk or an indirect effect that is mediated by other variables. It can also reveal risk factors that might not be evident in univariate analyses; if a variable's effect is moderated by other variables, its association with risk may be apparent only after adjustment for the other variables. Most important, multivariate analyses can identify combinations of risk factors that are more predictive of risk than individual risk factors. HYPOTHESIS A diverse combination of risk factors predispose athletes to first-time noncontact ACL injury, and these relationships are different for male and female athletes. STUDY DESIGN Case-control study; Level of evidence, 3. METHODS Athletes competing in organized sports at the high school and college levels participated in this study. Data from injured subjects (109 suffering an ACL injury) and matched controls (227 subjects) from the same athletic team were analyzed with multivariate conditional logistic regression to examine the effects of combinations of variables (demographic characteristics, joint laxity, lower extremity alignment, strength, and personality traits) on the risk of suffering their first ACL injury and to construct risk models. RESULTS For male athletes, increases in anterior-posterior displacement of the tibia relative to the femur (knee laxity), posterior knee stiffness, navicular drop, and a decrease in standing quadriceps angle were jointly predictive of suffering an ACL injury. For female athletes the combined effects of having a parent who had suffered an ACL injury and increases in anterior-posterior knee laxity and body mass index were predictive of ACL injury. CONCLUSION Multivariate models provided more information about ACL injury risk than individual risk factors. Both male and female risk models included increased anterior-posterior knee laxity as a predictor of ACL injury but were otherwise dissimilar.
Collapse
Affiliation(s)
- Pamela M Vacek
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA
| | - James R Slauterbeck
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Timothy W Tourville
- Department of Rehabilitation and Movement Science, University of Vermont, Burlington, Vermont, USA
| | - Daniel R Sturnick
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Leigh-Ann Holterman
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA
| | - Helen C Smith
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Robert J Johnson
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Kelly J Tourville
- Department of Rehabilitation and Movement Science, University of Vermont, Burlington, Vermont, USA
| | - Bruce D Beynnon
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| |
Collapse
|
33
|
Tripp SG, Ford KR, Shultz SJ, Nguyen AD, Taylor JB. Single-Sport Athletes Exhibit More Lower Extremity Valgus than Multi-Sport Athletes. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000485861.72512.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
34
|
Mulrey C, Ford KR, Shultz SJ, Nguyen AD, Taylor JB. Identifying Limb Dominance in Adolescent Female Basketball Players. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000487223.05252.0e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
35
|
Tourville TW, Shultz SJ, Vacek PM, Knudsen EJ, Bernstein IM, Tourville KJ, Hardy DM, Johnson RJ, Slauterbeck JR, Beynnon BD. Evaluation of an Algorithm to Predict Menstrual-Cycle Phase at the Time of Injury. J Athl Train 2016; 51:47-56. [PMID: 26807868 DOI: 10.4085/1062-6050-51.3.01] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Women are 2 to 8 times more likely to sustain an anterior cruciate ligament (ACL) injury than men, and previous studies indicated an increased risk for injury during the preovulatory phase of the menstrual cycle (MC). However, investigations of risk rely on retrospective classification of MC phase, and no tools for this have been validated. OBJECTIVE To evaluate the accuracy of an algorithm for retrospectively classifying MC phase at the time of a mock injury based on MC history and salivary progesterone (P4) concentration. DESIGN Descriptive laboratory study. SETTING Research laboratory. PARTICIPANTS Thirty-one healthy female collegiate athletes (age range, 18-24 years) provided serum or saliva (or both) samples at 8 visits over 1 complete MC. MAIN OUTCOME MEASURE(S) Self-reported MC information was obtained on a randomized date (1-45 days) after mock injury, which is the typical timeframe in which researchers have access to ACL-injured study participants. The MC phase was classified using the algorithm as applied in a stand-alone computational fashion and also by 4 clinical experts using the algorithm and additional subjective hormonal history information to help inform their decision. To assess algorithm accuracy, phase classifications were compared with the actual MC phase at the time of mock injury (ascertained using urinary luteinizing hormone tests and serial serum P4 samples). Clinical expert and computed classifications were compared using κ statistics. RESULTS Fourteen participants (45%) experienced anovulatory cycles. The algorithm correctly classified MC phase for 23 participants (74%): 22 (76%) of 29 who were preovulatory/anovulatory and 1 (50%) of 2 who were postovulatory. Agreement between expert and algorithm classifications ranged from 80.6% (κ = 0.50) to 93% (κ = 0.83). Classifications based on same-day saliva sample and optimal P4 threshold were the same as those based on MC history alone (87.1% correct). Algorithm accuracy varied during the MC but at no time were both sensitivity and specificity levels acceptable. CONCLUSIONS These findings raise concerns about the accuracy of previous retrospective MC-phase classification systems, particularly in a population with a high occurrence of anovulatory cycles.
Collapse
Affiliation(s)
- Timothy W Tourville
- Department of Rehabilitation and Movement Science, University of Vermont, Burlington
| | - Sandra J Shultz
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Pamela M Vacek
- Medical Biostatistics Unit, University of Vermont, Burlington
| | | | - Ira M Bernstein
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont, Burlington
| | - Kelly J Tourville
- Department of Rehabilitation and Movement Science, University of Vermont, Burlington
| | - Daniel M Hardy
- Department of Cell Biology and Biochemistry, Texas Tech University, Lubbock
| | - Robert J Johnson
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont, Burlington
| | - James R Slauterbeck
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Vermont, Burlington
| | - Bruce D Beynnon
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington
| |
Collapse
|
36
|
Abstract
CONTEXT Greater knee-joint laxity may lead to a higher risk of knee injury, yet it is unknown whether results of self-reported outcome measures are associated with distinct knee-laxity profiles. OBJECTIVE To identify the extent to which multiplanar knee laxity is associated with patient-reported outcomes of knee function in healthy individuals during activities of daily living and sport. DESIGN Descriptive laboratory study. SETTING University research laboratory. PATIENTS OR OTHER PARTICIPANTS Forty healthy individuals (20 men, 20 women; age = 18-31 years). MAIN OUTCOME MEASURE(S) All participants were given the Knee Outcome Survey Activities of Daily Living Scale (KOS-ADL) and Sports Activities Scale (KOS-SAS) and subsequently measured for knee laxity in the sagittal, frontal, and transverse planes. Separate backward stepwise regression analyses were performed to determine the extent to which multiplanar knee-laxity values predicted KOS-ADL and KOS-SAS scores within each sex. RESULTS Women had higher magnitudes of anterior, posterior (POST(LAX)), varus (VAR(LAX)), valgus (VAL(LAX)), and internal-rotation laxity than men and trended toward greater external rotation (ER(LAX)) laxity. Greater POST(LAX), less VAL(LAX), and greater VAR(LAX) was associated with lower KOS-ADL scores (KOS-ADL = -4.8 [POST(LAX)], + 3.3 [VAL(LAX)] - 2.2 [VAR(LAX)] + 100.4, R2 = 0.74, P < .001) and greater POST(LAX) and less VAL(LAX) was associated with lower KOS-SAS scores (KOS-SAS = -8.2 [POST(LAX)], + 3.6 [VAL(LAX)] + 96.4, R2 = 0.67, P < .001) in women. In men, greater POST(LAX) and less ER(LAX) was associated with lower KOS-SAS scores (KOS-ADL = -4.7 [POST(LAX)], + 0.9 [ER(LAX)] + 96.4, R2 = 0.49, P < .001). CONCLUSIONS The combination of POST(LAX) with less relative VAL(LAX) (women) or less relative ER(LAX) (men) was a strong predictor of KOS scores, suggesting that a self-reported outcome measure may be beneficial as part of a preparticipation screening battery to identify those with perceived functional deficits associated with their knee laxity.
Collapse
Affiliation(s)
| | - Hsin-Min Wang
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Randy J. Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro
| | | | - Scott E. Ross
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro
| |
Collapse
|
37
|
Shultz SJ, Schmitz RJ, Benjaminse A, Collins M, Ford K, Kulas AS. ACL Research Retreat VII: An Update on Anterior Cruciate Ligament Injury Risk Factor Identification, Screening, and Prevention. J Athl Train 2015; 50:1076-93. [PMID: 26340613 PMCID: PMC4641546 DOI: 10.4085/1062-6050-50.10.06] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Randy J. Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro
| | - Anne Benjaminse
- The Department of Human Movement Sciences, University of Groningen, and The School of Sports Studies, Hanze University, Groningen, The Netherlands
| | - Malcolm Collins
- Department of Human Biology, University of Cape Town, South Africa
| | - Kevin Ford
- Human Biomechanics and Physiology Laboratory, Department of Physical Therapy, High Point University, NC
| | - Anthony S. Kulas
- Department of Health Education and Promotion, Eastern Carolina University, Greenville, NC
| |
Collapse
|
38
|
Beynnon BD, Sturnick DR, Argentieri EC, Slauterbeck JR, Tourville TW, Shultz SJ, Vacek PM. A Sex-Stratified Multivariate Risk Factor Model for Anterior Cruciate Ligament Injury. J Athl Train 2015; 50:1094-6. [PMID: 26340614 PMCID: PMC4641547 DOI: 10.4085/1062-6050-50.10.05] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Bruce D. Beynnon
- McClure Musculoskeletal Research Center, Department of Orthopedics and Rehabilitation, University of Vermont College of Medicine, Burlington
| | | | - Erin C. Argentieri
- McClure Musculoskeletal Research Center, Department of Orthopedics and Rehabilitation, University of Vermont College of Medicine, Burlington
| | - James R. Slauterbeck
- McClure Musculoskeletal Research Center, Department of Orthopedics and Rehabilitation, University of Vermont College of Medicine, Burlington
| | - Timothy W. Tourville
- McClure Musculoskeletal Research Center, Department of Orthopedics and Rehabilitation, University of Vermont College of Medicine, Burlington
| | - Sandra J. Shultz
- Biostatistics Unit, University of Vermont College of Medicine, Burlington
| | - Pamela M. Vacek
- Department of Kinesiology, University of North Carolina at Greensboro
| |
Collapse
|
39
|
Shea KG, Carey JL, Richmond J, Sandmeier R, Pitts RT, Polousky JD, Chu C, Shultz SJ, Ellen M, Smith A, LaBella CR, Anderson AF, Musahl V, Myer GD, Jevsevar D, Bozic KJ, Shaffer W, Cummins D, Murray JN, Patel N, Shores P, Woznica A, Martinez Y, Gross L, Sevarino K. The American Academy of Orthopaedic Surgeons evidence-based guideline on management of anterior cruciate ligament injuries. J Bone Joint Surg Am 2015; 97:672-4. [PMID: 25878313 DOI: 10.2106/jbjs.n.01257] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
40
|
Sturnick DR, Vacek PM, DeSarno MJ, Gardner-Morse MG, Tourville TW, Slauterbeck JR, Johnson RJ, Shultz SJ, Beynnon BD. Combined anatomic factors predicting risk of anterior cruciate ligament injury for males and females. Am J Sports Med 2015; 43:839-47. [PMID: 25583759 PMCID: PMC6607022 DOI: 10.1177/0363546514563277] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Knee joint geometry has been associated with risk of suffering an anterior cruciate ligament (ACL) injury; however, few studies have utilized multivariate analysis to investigate how different aspects of knee joint geometry combine to influence ACL injury risk. HYPOTHESES Combinations of knee geometry measurements are more highly associated with the risk of suffering a noncontact ACL injury than individual measurements, and the most predictive combinations of measurements are different for males and females. STUDY DESIGN Case-control study; Level of evidence, 3. METHODS A total of 88 first-time, noncontact, grade III ACL-injured subjects and 88 uninjured matched-control subjects were recruited, and magnetic resonance imaging data were acquired. The geometry of the tibial plateau subchondral bone, articular cartilage, and meniscus; geometry of the tibial spines; and size of the femoral intercondylar notch and ACL were measured. Multivariate conditional logistic regression was used to develop risk models for ACL injury in females and males separately. RESULTS For females, the best fitting model included width of the femoral notch at its anterior outlet and the posterior-inferior-directed slope of the lateral compartment articular cartilage surface, where a millimeter decrease in notch width and a degree increase in slope were independently associated with a 50% and 32% increase in risk of ACL injury, respectively. For males, a model that included ACL volume and the lateral compartment posterior meniscus to subchondral bone wedge angle was most highly associated with risk of ACL injury, where a 0.1 cm3 decrease in ACL volume (approximately 8% of the mean value) and a degree decrease in meniscus wedge angle were independently associated with a 43% and 23% increase in risk, correspondingly. CONCLUSION Combinations of knee joint geometry measurements provided more information about the risk of noncontact ACL injury than individual measures, and the aspects of geometry that best explained the relationship between knee geometry and the risk of injury were different between males and females. Consequently, a female with both a decreased femoral notch width and an increased posterior-inferior-directed lateral compartment tibial articular cartilage slope combined or a male with a decreased ACL volume and decreased lateral compartment posterior meniscus angle were most at risk for sustaining an ACL injury.
Collapse
Affiliation(s)
- Daniel R. Sturnick
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Pamela M. Vacek
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA
| | - Michael J. DeSarno
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA
| | - Mack G. Gardner-Morse
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Timothy W. Tourville
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - James R. Slauterbeck
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Robert J. Johnson
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Bruce D. Beynnon
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont, USA., Address correspondence to Bruce D. Beynnon, PhD, McClure Musculoskeletal Research Center, Department of Orthopedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT 05405, USA
| | | |
Collapse
|
41
|
Shultz SJ, Schmitz RJ, Cone JR, Henson RA, Montgomery MM, Pye ML, Tritsch AJ. Changes in fatigue, multiplanar knee laxity, and landing biomechanics during intermittent exercise. J Athl Train 2015; 50:486-97. [PMID: 25674926 DOI: 10.4085/1062-6050-49.5.08] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Knee laxity increases during exercise. However, no one, to our knowledge, has examined whether these increases contribute to higher-risk landing biomechanics during prolonged, fatiguing exercise. OBJECTIVES To examine associations between changes in fatigue (measured as sprint time [SPTIME]), multiplanar knee laxity (anterior-posterior [APLAX], varus-valgus [VVLAX] knee laxity, and internal-external rotation [IERLAX]) knee laxity and landing biomechanics during prolonged, intermittent exercise. DESIGN Descriptive laboratory study. SETTING Laboratory and gymnasium. PATIENTS OR OTHER PARTICIPANTS A total of 30 male (age = 20.3 ± 2.0 years, height = 1.79 ± 0.05 m, mass = 75.2 ± 7.2 kg) and 29 female (age = 20.5 ± 2.3 years, height = 1.67 ± 0.08 m, mass = 61.8 ± 9.0 kg) competitive athletes. INTERVENTION(S) A 90-minute intermittent exercise protocol (IEP) designed to simulate the physiologic and biomechanical demands of a soccer match. MAIN OUTCOME MEASURE(S) We measured SPTIME, APLAX, and landing biomechanics before and after warm-up, every 15 minutes during the IEP, and every 15 minutes for 1 hour after the IEP. We measured VVLAX and IERLAX before and after the warm-up, at 45 and 90 minutes during the IEP, and at 30 minutes after the IEP. We used hierarchical linear modeling to examine associations between exercise-related changes in SPTIME and knee laxity with exercise-related changes in landing biomechanics while controlling for initial (before warm-up) knee laxity. RESULTS We found that SPTIME had a more global effect on landing biomechanics in women than in men, resulting in a more upright landing and a reduction in landing forces and out-of-plane motions about the knee. As APLAX increased with exercise, women increased their knee internal-rotation motion (P = .02), and men increased their hip-flexion motion and energy-absorption (P = .006) and knee-extensor loads (P = .04). As VVLAX and IERLAX increased, women went through greater knee-valgus motion and dorsiflexion and absorbed more energy at the knee (P ≤ .05), whereas men were positioned in greater hip external and knee internal rotation and knee valgus throughout the landing (P = .03). The observed fatigue- and laxity-related changes in landing biomechanics during exercise often depended on initial knee laxity. CONCLUSIONS Both exercise-related changes in fatigue and knee laxity were associated with higher-risk landing biomechanics during prolonged exercise. These relationships were more pronounced in participants with greater initial knee laxity.
Collapse
Affiliation(s)
- Sandra J Shultz
- Applied Neuromechanics Research Laboratory, Department of Kinesiology, University of North Carolina at Greensboro
| | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
CONTEXT Whereas static lower extremity alignment (LEA) has been identified as a risk factor for anterior cruciate ligament injury, little is known about its influence on joint motion and moments commonly associated with anterior cruciate ligament injury. OBJECTIVE To cluster participants according to combinations of LEA variables and compare these clusters in hip- and knee-joint kinematics and kinetics during the landing phase of a drop-jump task. DESIGN Descriptive laboratory study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 141 participants (50 men: age = 22.2 ± 2.8 years, height = 177.9 ± 9.3 cm, weight = 80.9 ± 13.3 kg; 91 women: age = 21.2 ± 2.6 years, height = 163.9 ± 6.6 cm, weight = 61.1 ± 8.7 kg). MAIN OUTCOME MEASURE(S) Static LEA included pelvic angle, femoral anteversion, quadriceps angle, tibiofemoral angle, genu recurvatum, tibial torsion, and navicular drop. Cluster analysis grouped participants according to their static LEA profiles, and these groups were compared on their hip- and knee-joint kinematics and external moments during the landing phase of a double-legged drop jump. RESULTS Three distinct clusters (C1-C3) were identified based on their static LEAs. Participants in clusters characterized with static internally rotated hip and valgus knee posture (C1) and externally rotated knee and valgus knee posture (C3) alignments demonstrated greater knee-valgus motion and smaller hip-flexion moments than the cluster with more neutral static alignment (C2). Participants in C1 also experienced greater hip internal-rotation and knee external-rotation moments than those in C2 and C3. CONCLUSIONS Static LEA clusters that are positioned anatomically with a more rotated and valgus knee posture experienced greater dynamic valgus along with hip and knee moments during landing. Whereas static LEA contributes to differences in hip and knee rotational moments, sex may influence the differences in frontal-plane knee kinematics and sagittal-plane hip moments.
Collapse
|
43
|
Schmitz RJ, Kim H, Shultz SJ. Neuromuscular fatigue and tibiofemoral joint biomechanics when transitioning from non-weight bearing to weight bearing. J Athl Train 2014; 50:23-9. [PMID: 25375932 DOI: 10.4085/1062-6050-49.3.79] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
CONTEXT Fatigue is suggested to be a risk factor for anterior cruciate ligament injury. Fatiguing exercise can affect neuromuscular control and laxity of the knee joint, which may render the knee less able to resist externally applied loads. Few authors have examined the effects of fatiguing exercise on knee biomechanics during the in vivo transition of the knee from non-weight bearing to weight bearing, the time when anterior cruciate ligament injury likely occurs. OBJECTIVE To investigate the effect of fatiguing exercise on tibiofemoral joint biomechanics during the transition from non-weight bearing to early weight bearing. DESIGN Cross-sectional study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Ten participants (5 men and 5 women; age = 25.3 ± 4.0 years) with no previous history of knee-ligament injury to the dominant leg. INTERVENTION(S) Participants were tested before (preexercise) and after (postexercise) a protocol consisting of repeated leg presses (15 repetitions from 10°-40° of knee flexion, 10 seconds' rest) against a 60% body-weight load until they were unable to complete a full bout of repetitions. MAIN OUTCOME MEASURE(S) Electromagnetic sensors measured anterior tibial translation and knee-flexion excursion during the application of a 40% body-weight axial compressive load to the bottom of the foot, simulating weight acceptance. A force transducer recorded axial compressive force. RESULTS The axial compressive force (351.8 ± 44.3 N versus 374.0 ± 47.9 N; P = .018), knee-flexion excursion (8.0° ± 4.0° versus 10.2° ± 3.7°; P = .046), and anterior tibial translation (6.7 ± 1.7 mm versus 8.2 ± 1.9 mm; P < .001) increased from preexercise to postexercise. No significant correlations were noted. CONCLUSIONS Neuromuscular fatigue may impair initial knee-joint stabilization during weight acceptance, leading to greater accessory motion at the knee and the potential for greater anterior cruciate ligament loading.
Collapse
Affiliation(s)
- Randy J Schmitz
- Department of Kinesiology, University of North Carolina at Greensboro
| | | | | |
Collapse
|
44
|
Sturnick DR, Van Gorder R, Vacek PM, DeSarno MJ, Gardner-Morse MG, Tourville TW, Slauterbeck JR, Johnson RJ, Shultz SJ, Beynnon BD. Tibial articular cartilage and meniscus geometries combine to influence female risk of anterior cruciate ligament injury. J Orthop Res 2014; 32:1487-94. [PMID: 25099246 PMCID: PMC6886124 DOI: 10.1002/jor.22702] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 07/01/2014] [Indexed: 02/04/2023]
Abstract
Tibial plateau subchondral bone geometry has been associated with the risk of sustaining a non-contact ACL injury; however, little is known regarding the influence of the meniscus and articular cartilage interface geometry on risk. We hypothesized that geometries of the tibial plateau articular cartilage surface and meniscus were individually associated with the risk of non-contact ACL injury. In addition, we hypothesized that the associations were independent of the underlying subchondral bone geometry. MRI scans were acquired on 88 subjects that suffered non-contact ACL injuries (27 males, 61 females) and 88 matched control subjects that were selected from the injured subject's teammates and were thus matched on sex, sport, level of play, and exposure to risk of injury. Multivariate analysis of the female data revealed that increased posterior-inferior directed slope of the middle articular cartilage region and decreased height of the posterior horn of the meniscus in the lateral compartment were associated with increased risk of sustaining a first time, non-contact ACL injury, independent of each other and of the slope of the tibial plateau subchondral bone. No measures were independently related to risk of non-contact ACL injury among males.
Collapse
Affiliation(s)
- Daniel R. Sturnick
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Robert Van Gorder
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Pamela M. Vacek
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont
| | - Michael J. DeSarno
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont
| | - Mack G. Gardner-Morse
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Timothy W. Tourville
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - James R. Slauterbeck
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Robert J. Johnson
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina Greensboro, Greensboro, North Carolina
| | - Bruce D. Beynnon
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| |
Collapse
|
45
|
Sturnick DR, Argentieri EC, Vacek PM, DeSarno MJ, Gardner-Morse MG, Tourville TW, Slauterbeck JR, Johnson RJ, Shultz SJ, Beynnon BD. A decreased volume of the medial tibial spine is associated with an increased risk of suffering an anterior cruciate ligament injury for males but not females. J Orthop Res 2014; 32:1451-7. [PMID: 24962098 PMCID: PMC6604057 DOI: 10.1002/jor.22670] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/18/2014] [Indexed: 02/04/2023]
Abstract
Measurements of tibial plateau subchondral bone and articular cartilage slope have been associated with the risk of suffering anterior cruciate ligament (ACL) injury. Such single-plane measures of the tibial plateau may not sufficiently characterize its complex, three-dimensional geometry and how it relates to knee injury. Further, the tibial spines have not been studied in association with the risk of suffering a non-contact ACL injury. We questioned whether the geometries of the tibial spines are associated with non-contact ACL injury risk, and if this relationship is different for males and females. Bilateral MRI scans were acquired on 88 ACL-injured subjects and 88 control subjects matched for sex, age and sports team. Medial and lateral tibial spine geometries were characterized with measurements of length, width, height, volume and anteroposterior location. Analyses of females revealed no associations between tibial spine geometry and risk of ACL injury. Analyses of males revealed that an increased medial tibial spine volume was associated with a decreased risk of ACL injury (OR = 0.667 per 100 mm(3) increase). Smaller medial spines could provide less resistance to internal rotation and medial translation of the tibia relative to the femur, subsequently increasing ACL strains and risk of ACL injury.
Collapse
Affiliation(s)
- Daniel R. Sturnick
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Erin C. Argentieri
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Pamela M. Vacek
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont
| | - Michael J. DeSarno
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont
| | - Mack G. Gardner-Morse
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Timothy W. Tourville
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - James R. Slauterbeck
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Robert J. Johnson
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Bruce D. Beynnon
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| |
Collapse
|
46
|
Fan L, Copple TJ, Tritsch AJ, Shultz SJ. Clinical and instrumented measurements of hip laxity and their associations with knee laxity and general joint laxity. J Athl Train 2014; 49:590-8. [PMID: 25098747 DOI: 10.4085/1062-6050-49.3.86] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Hip-joint laxity may be a relevant anterior cruciate ligament injury risk factor. With no devices currently available to measure hip laxity, it is important to determine if clinical measurements sufficiently capture passive displacement of the hip. OBJECTIVE To examine agreement between hip internal-external-rotation range of motion measured clinically (HIER(ROM)) versus internal-external-rotation laxity measured at a fixed load (HIER(LAX)) and to determine their relationships with knee laxity (anterior-posterior [KAP(LAX)], varus-valgus [KVV(LAX)], and internal-external rotation [KIER(LAX)]) and general joint laxity (GJL). Design : Cross-sectional study. SETTING Controlled research laboratory. PATIENTS OR OTHER PARTICIPANTS Thirty-two healthy adults (16 women, 16 men; age = 25.56 ± 4.08 years, height = 170.94 ± 10.62 cm, weight = 68.86 ± 14.89 kg). MAIN OUTCOME MEASURE(S) Participants were measured for HIER(ROM), HIER(LAX) at 0° and 30° hip flexion (-10 Nm, 7 Nm), KAP(LAX) (-90 N to 133 N), KVV(LAX) (±10 Nm), KIER(LAX) (±5 Nm), and GJL. We calculated Pearson correlations and 95% limits of agreement between HIER(ROM) and HIER(LAX)_0° and HIER(LAX)_30°. Correlation analyses examined the strength of associations between hip laxity, knee laxity, and GJL. RESULTS The HIER(ROM) and HIER(LAX) had similar measurement precision and were strongly correlated (r > 0.78). However, HIER(ROM) was systematically smaller in magnitude than HIER(LAX) at 0° (95% limits of agreement = 29.0° ± 22.3°) and 30° (21.4° ± 19.3°). The HIER(ROM) (r = 0.51-0.66), HIER(LAX)_0° (r = 0.52-0.69) and HIER(LAX)_30° (r = 0.53-0.76) were similarly correlated with knee laxity measures and GJL. The combinations of KVV(LAX) and either HIER(ROM), HIER(LAX)_0°, or HIER(LAX)_30° (R2 range, 0.42-0.44) were the strongest predictors of GJL. CONCLUSIONS Although HIER(ROM) and HIER(LAX) differed in magnitude, they were measured with similar consistency and precision and were similarly correlated with knee laxity and GJL measures. Individuals with greater GJL also had greater hip laxity. These findings are relevant to clinicians and investigators conducting prospective risk factor studies, given the need for accessible, efficient, and low-cost alternatives for characterizing an individual's laxity profile.
Collapse
Affiliation(s)
- Lixia Fan
- Shandong Normal University, Jinan, China
| | | | | | | |
Collapse
|
47
|
Montgomery MM, Shultz SJ, Schmitz RJ. The effect of equalizing landing task demands on sex differences in lower extremity energy absorption. Clin Biomech (Bristol, Avon) 2014; 29:760-6. [PMID: 24998904 DOI: 10.1016/j.clinbiomech.2014.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 05/29/2014] [Accepted: 06/02/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND Less lean mass and strength may result in greater relative task demands on females compared to males when landing from a standardized height and could explain sex differences in energy absorption strategies. We compared the magnitude of sex differences in energy absorption when task demands were equalized relative to the amount of lower extremity lean mass available to dissipate kinetic energy upon landing. METHODS Male-female pairs (n=35) were assessed for lower extremity lean mass with dual-energy X-ray absorptiometry. Relative task demands were calculated when landing from a standardized height. Based on the difference in lower extremity lean mass within each pair, task demands were equalized by increasing the drop height for males. Joint energetics were measured while landing from the two heights. Multivariate repeated measures ANOVAs compared the magnitude of sex differences in joint energetics between conditions. FINDINGS The multivariate test for absolute energy absorption was significant (P<0.01). The magnitude of sex difference in energy absorption was greater at the hip and knee (both P<0.01), but not the ankle (P=0.43) during the equalized condition compared to the standardized and exaggerated conditions (all P<0.01). There was no difference in the magnitude of sex differences between equalized, standardized and exaggerated conditions for relative energy absorption (P=0.18). INTERPRETATION Equalizing task demands increased the difference in absolute hip and knee energy absorption between sexes, but had no effect on relative joint contributions to total energy absorption. Sex differences in energy absorption are likely influenced by factors other than differences in relative task demands.
Collapse
Affiliation(s)
- Melissa M Montgomery
- Department of Kinesiology, California State University, Northridge, Northridge, CA, USA
| | - Sandra J Shultz
- Applied Neuromechanics Research Laboratory, Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Randy J Schmitz
- Applied Neuromechanics Research Laboratory, Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA
| |
Collapse
|
48
|
Whitney DC, Sturnick DR, Vacek PM, DeSarno MJ, Gardner-Morse M, Tourville TW, Smith HC, Slauterbeck JR, Johnson RJ, Shultz SJ, Hashemi J, Beynnon BD. Relationship Between the Risk of Suffering a First-Time Noncontact ACL Injury and Geometry of the Femoral Notch and ACL: A Prospective Cohort Study With a Nested Case-Control Analysis. Am J Sports Med 2014; 42:1796-805. [PMID: 24866891 PMCID: PMC6604056 DOI: 10.1177/0363546514534182] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The morphometric characteristics of the anterior cruciate ligament (ACL) and the femoral intercondylar notch within which it resides have been implicated as risk factors for injuries to this important stabilizer of the knee. Prior research has produced equivocal results with differing methodologies, and consequently, it is unclear how these characteristics affect the injury risk in male and female patients. HYPOTHESIS The morphometric characteristics of the ACL and femoral intercondylar notch are individually and independently associated with the risk of suffering a noncontact ACL injury, and these relationships are different in male and female patients. STUDY DESIGN Case-control study; Level of evidence, 3. METHODS Magnetic resonance imaging scans of the bilateral knees were obtained on 88 case-control pairs (27 male, 61 female) matched for age, sex, and participation on the same sports team. Patients had suffered a grade III, first-time, noncontact ACL tear. The femoral notch width at 4 locations, the thickness of the bony ridge at the anteromedial outlet of the femoral notch, the femoral notch volume, ACL volume, and ACL cross-sectional area were measured. RESULTS Multivariate analysis of combined data from male and female patients revealed that decreased ACL volume (odds ratio [OR], 0.829), decreased femoral notch width (OR, 0.700), and increased bony ridge thickness at the anteromedial outlet of the femoral notch (OR, 1.614) were significant independent predictors of an ACL injury. Separate analyses of male and female patients indicated that the femoral notch ridge may be more strongly associated with a risk in female patients, while ACL volume is more strongly associated with a risk in male patients. However, statistical analysis performed with an adjustment for body weight strengthened the association between ACL volume and the risk of injuries in female patients. CONCLUSION Morphometric features of both the ACL and femoral notch combine to influence the risk of suffering a noncontact ACL injury. When included together in a multivariate model that adjusts for body weight, the effects of the morphometric measurements are similar in male and female patients. If body weight is not taken into consideration, ACL volume is not associated with a risk in female patients.
Collapse
Affiliation(s)
- Darryl C. Whitney
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Daniel R. Sturnick
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Pamela M. Vacek
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA
| | - Mike J. DeSarno
- Department of Medical Biostatistics, University of Vermont, Burlington, Vermont, USA
| | - Mack Gardner-Morse
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Timothy W. Tourville
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Helen C. Smith
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - James R. Slauterbeck
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Robert J. Johnson
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina, USA
| | - Javad Hashemi
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, Florida, USA
| | - Bruce D. Beynnon
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, Vermont, USA.,Address correspondence to Bruce D. Beynnon, PhD, McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, 438A Robert T. Stafford Hall, 95 Carrigan Drive, Burlington, VT 05405, USA ( )
| |
Collapse
|
49
|
Beynnon BD, Vacek PM, Newell MK, Tourville TW, Smith HC, Shultz SJ, Slauterbeck JR, Johnson RJ. The Effects of Level of Competition, Sport, and Sex on the Incidence of First-Time Noncontact Anterior Cruciate Ligament Injury. Am J Sports Med 2014; 42:1806-12. [PMID: 25016012 PMCID: PMC6604059 DOI: 10.1177/0363546514540862] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Anterior cruciate ligament (ACL) injuries are disabling and are associated with the early onset of posttraumatic osteoarthritis. Little is known regarding the incidence rate of first-time noncontact ACL injuries sustained during athletic events and how they are independently influenced by level of competition, type of sport, and the participant's sex. HYPOTHESIS Level of competition (college or high school), type of sport (soccer, basketball, lacrosse, field hockey, football, rugby, volleyball), and the athlete's sex independently influence the incidence rate of first-time noncontact ACL injuries. STUDY DESIGN Cohort study; Level of evidence, 2. METHODS Between fall 2008 and spring 2012, first-time noncontact ACL injury data were collected from 8 colleges and 18 high schools across 7 sports. Athlete exposure was computed retrospectively using team rosters and numbers of scheduled practices and games. Injury incidence rates (IRs) were computed per 1000 athlete exposures. The independent effects of level of competition, sport, and sex on ACL injury risk were estimated by Poisson regression. RESULTS Colleges reported 48 ACL injuries with 320,719 athlete exposures across all sports studied (IR = 0.150 per 1000 person-days), while high schools reported 53 injuries with 873,057 athlete exposures (IR = 0.061). After adjustment for differences in sport and sex, college athletes had a significantly higher injury risk than did high school athletes (adjusted relative risk [RR], 2.38; 95% CI, 1.55-3.54). The overall IR for female athletes was 0.112 compared with 0.063 for males. After adjustment for sport and level of play, females were more than twice as likely to have a first-time ACL injury compared with males (RR, 2.10; 95% CI, 1.34-3.27). With lacrosse as the reference group, risk of first-time noncontact ACL injury was significantly higher for soccer players (RR, 1.77) and for rugby players (RR, 2.23), independent of level of play and sex. CONCLUSION An athlete's risk of having a first-time noncontact ACL injury is independently influenced by level of competition, the participant's sex, and type of sport, and there are no interactions between their effects. Female college athletes have the highest risk of having a first-time noncontact ACL injury among the groups studied.
Collapse
Affiliation(s)
- Bruce D. Beynnon
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT, USA.,Address correspondence to Bruce D. Beynnon, PhD, McClure Professor, McClure Musculoskeletal Research Center, Department of Orthopedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT 05405-0084, USA ()
| | - Pamela M. Vacek
- Department of Medical Biostatistics, University of Vermont, Burlington, VT, USA
| | - Maira K. Newell
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT, USA
| | - Timothy W. Tourville
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT, USA
| | - Helen C. Smith
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT, USA
| | - Sandra J. Shultz
- Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - James R. Slauterbeck
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT, USA
| | - Robert J. Johnson
- McClure Musculoskeletal Research Center, Department of Orthopaedics and Rehabilitation, University of Vermont College of Medicine, Burlington, VT, USA
| |
Collapse
|
50
|
Norcross MF, Shultz SJ, Weinhold PS, Lewek MD, Padua DA, Blackburn JT. The influences of sex and posture on joint energetics during drop landings. Scand J Med Sci Sports 2014; 25:e166-75. [PMID: 24995548 DOI: 10.1111/sms.12263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2014] [Indexed: 01/14/2023]
Abstract
Previous observations suggest that females utilize a more erect initial landing posture than males with sex differences in landing posture possibly related to sex-specific energy absorption (EA) strategies. However, sex-specific EA strategies have only been observed when accompanied by sex differences in initial landing posture. This study (a) investigated the potential existence of sex-specific EA strategies; and (b) determined the influences of sex and initial landing posture on the biomechanical determinants of EA. The landing biomechanics of 80 subjects were recorded during drop landings in Preferred, Flexed, and Erect conditions. No sex differences in joint EA were identified after controlling for initial landing posture. Males and females exhibited greater ankle EA during Erect vs Flexed landings with this increase driven by 12% greater ankle velocity, but no change in ankle extensor moment. No differences in hip and knee EA were observed between conditions. However, to achieve similar knee EA, subjects used 7% greater mean knee extensor moment but 9% less knee angular velocity during Flexed landings. The results suggest that sex-specific EA strategies do not exist, and that the magnitude of knee joint EA can be maintained by modulating the relative contributions of joint moment and angular velocity to EA.
Collapse
Affiliation(s)
- M F Norcross
- School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA
| | | | | | | | | | | |
Collapse
|