Effect of functional stabilization training on lower limb biomechanics in women

The effect of a suspension training on physical fitness, lower extremity biomechanical factors, and occupational health in Navy personnel: a randomized controlled trial

Optimal physical fitness is essential for military personnel to effectively meet their rigorous physical demands. This study aimed to investigate the effectiveness of a suspension training program on physical fitness, biomechanical risk factors for lower extremity injury, mental health, and work-related factors in Navy personnel. A total of 50 young men participated in a randomized controlled trial. The participants were randomly assigned to two groups (n = 25): the intervention group and the control group. The intervention group performed an eight-week suspension training session three times per week, while the control group maintained their daily duties. The primary outcome was physical performance. The secondary outcomes were determined biomechanical risk factors for lower extremity injuries, mental health, and work-related factors. The data were analyzed using the analysis of covariance (ANCOVA). Compared with the control group, the intervention group showed significant improvements in physical performance, biomechanical risk for lower extremity injuries, and work-related factors from baseline to follow-up (p ≤ 0.05). However, there was no improvement in mental health. Based on these findings, suspension training positively impacted physical fitness, reduced injury risk, and enhanced the work-related factors of Navy personnel. This study provides new insights for various related experts and military coaches because it is an easy-to-use and feasible method with minimal facilities.

Effect of Functional Scapular Stabilization Training on Function and Pain in Frozen Shoulder Syndrome: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to determine the effect of functional scapular stabilization training compared with the standard physical therapy on function and pain in people with frozen shoulder syndrome (FSS).

METHODS

In a single-blind randomized controlled trial, 86 people with FSS were randomly allocated into the intervention group (functional stabilization training [n = 43]) and control group (standard physical therapy [n = 43]) using block randomization for 12 weeks. The primary outcome measures were the Shoulder Pain and Disability Index and the numeric pain rating scale. The secondary outcome measures were range of motion (ROM), range of passive abduction, and coracoid pain test. All the outcome measures were carried out by an independent blind outcome assessor at baseline and at the end of 12 weeks.

RESULTS

A significant group × time interaction effect was observed for the Shoulder Pain and Disability Index (95% CI, 2.95-16.74; P < .01) and the numeric pain rating scale (95% CI, 0.67-2.07; P < .01) at the end of 12 weeks. The external rotation ROM showed a statistical significance with a mean change of 7.8° and P value of <.01.

CONCLUSION

The present findings show that scapular functional stabilization training resulted in improvement of function, reduction in pain, and greater improvement in external rotation ROM in patients with FSS. Also, our study findings suggest the involvement of rotator interval and inferior soft-tissue structures as indicated by the coracoid pain test and range of passive abduction.

The effectiveness of the comprehensive corrective exercise program on kinematics and strength of lower extremities in males with dynamic knee valgus: a parallel-group randomized wait-list controlled trial

Background

Dynamic knee valgus (DKV) is a prevalent movement impairment widely regarded as a risk factor for lower extremity disorders such as patellofemoral pain syndrome. The present study aimed to investigate the effectiveness of the comprehensive corrective exercise program (CCEP) on kinematics and strength of lower extremities in males with DKV.

Methods

Thirty asymptomatic young men with DKV between the ages of 18 and 28 years participated in this study. They were randomly assigned to the intervention (n = 15) and control groups (n = 15). The intervention group performed the CCEP for three sessions per week for eight weeks, while the control group only did activities of daily living. Hip external rotator and abductor muscle strength and three-dimensional lower extremity kinematics consisting of knee varus/valgus, femur adduction/abduction, femur medial/lateral rotation, and tibial medial/lateral rotation were measured at the baseline and post-test. The data were analyzed using the analysis of covariance (ANCOVA).

Results

There were significant improvements in all kinematics variables in the intervention group after the 8-week CCEP. Moreover, the strength of abductor and external rotator muscle improved in the intervention group (P < 0.05).

Conclusions

The CCEP led to substantial improvements in the selected variables of lower extremity kinematics and muscle strength in participants with DKV during a single-leg squat. These results imply that practitioners should adopt a comprehensive approach to pay simultaneous attention to both proximal and distal segments for improving DKV.

Trial registration

The protocol has been approved in the Registry of Clinical Trials (Registration N: IRCT20180821040843N1) on 2018-12-30.

Impaired muscle capacity of the hip and knee in individuals with isolated patellofemoral osteoarthritis: a cross-sectional study

AIMS

The aims of this study were to compare the capacity of the knee and hip muscles between individuals with and without isolated patellofemoral osteoarthritis (PFOA) and to evaluate the impact of PFOA on pain, stiffness, and physical function.

METHODS

This cross-sectional study evaluated muscle capacity of the hip and knee using an isokinetic dynamometer. The isokinetic variables used in the statistical analysis were peak torque, total work, and average power. Pain, stiffness, and physical function were assessed using questionnaires.

RESULTS

A total of 26 individuals participated in the study (13 with PFOA and 13 controls). The PFOA group exhibited lower peak torque, total work, and average power for knee extension and flexion in the concentric mode (p ⩽ 0.01) as well as lower peak torque and total work for knee extension (p ⩽ 0.005) and lower total work for knee flexion (p = 0.05) in the eccentric mode. The PFOA group exhibited lower peak torque of the extensor, abductor, adductor, and internal rotator muscles of the hip (p ⩽ 0.05), less total work of the abductor and adductor muscles (p ⩽ 0.04), and lower average power of eccentric adduction of the hip (p = 0.01) compared with the healthy controls. Compared with the control group, the PFOA group had a higher level of pain, stiffness, and compromised physical functioning self-reported (p ⩽ 0.005).

CONCLUSION

Participants with PFOA exhibited impairments regarding muscle capacity of the hip and knee, higher level of pain and stiffness as well as compromised physical functioning in comparison with healthy controls.

BIOMECHANICAL MEASURES DURING TWO SPORT-SPECIFIC TASKS DIFFERENTIATE BETWEEN SOCCER PLAYERS WHO GO ON TO ANTERIOR CRUCIATE LIGAMENT INJURY AND THOSE WHO DO NOT: A PROSPECTIVE COHORT ANALYSIS

Background

Decelerating and cutting are two common movements during which non-contact anterior cruciate ligament (ACL) injuries occur in soccer players. Retrospective video analysis of ACL injuries has demonstrated that players are often in knee valgus at the time of injury.

Purpose

To determine whether prospectively measured components of valgus collapse during a deceleration and 90 ° cut can differentiate between collegiate women's soccer players who go on to non-contact ACL injury.

Design

Secondary analysis of prospectively collected data.

Methods

51 NCAA women's soccer players completed motion analysis of a deceleration and 90 ° before the competitive season. Players were classified as Injured (noncontact ACL injury during the season) or Uninjured at the end of the season. Differences between groups for peak hip adduction, internal rotation, and knee abduction angles, and knee valgus collapse were analyzed with a MANOVA.

Results

Four non-contact ACL injuries were reported at the end of the season. There was a significant difference between groups for hip adduction angle during the 90 ° cut (p = 0.02) and deceleration (p = 0.03). Players who went on to ACL injury were in more hip adduction.

Conclusions

Hip adduction angle is larger in players who go on to ACL injury than those who do not during two sport-specific tasks. The components of knee injury prevention programs that address proximal control and strength are likely crucial for preventing ACL injuries.

Level of Evidence

2b.

Effect of two Dynamic Tape™ applications on the electromyographic activity of the gluteus medius and functional performance in women: A randomized, controlled, clinical trial

INTRODUCTION

Dynamic Tape™ (DT) is a biomechanical tape that is used to directly manage load, modify movement patterns, and assist functioning. However, no studies have evaluated its effectiveness in increasing gluteus medius (GM) muscle activation and improving functional performance.

OBJECTIVE

To investigate the effect of two forms of DT applications on the electromyographic (EMG) activity of the GM muscle and lower limb functional performance.

METHODS

Thirty-three, healthy, recreationally active women were randomly assigned into two groups: 1) submitted to the DT application on GM muscle that adhered to the stretching method for Kinesio Tape® application (KG, n = 17) and 2) submitted to the DT application on GM muscle that adhered to the stretching method suggested for DT (DG, n = 16). The EMG evaluation of GM was performed at rest, in maximum voluntary isometric contraction, and in the single-leg squat, drop landing, and jump landing + maximum vertical jump tests. Functional performance was evaluated using the triple hop test and the 6-m timed hop test.

RESULTS

No significant changes in GM activation or functional performance were found, regardless of the stretching method used. No significant intergroup differences were observed (α = 5%).

CONCLUSION

DT did not increase GM activation in functional activities, and it did not improve functional performance in the lower limbs in healthy women, regardless of the form of application used.

Do exercises for patellofemoral pain reflect common injury mechanisms? A systematic review

OBJECTIVES

Current best evidence has reported that therapeutic exercise programs that are designed to treat patellofemoral pain (PFP) should include both hip and knee specific exercises. The purpose of this review was to (1) examine the quality/comprehensiveness of exercise reporting in this field; (2) quantify the extent to which individual exercises comprised task-specific elements (single limb stance; eccentric control of the hip; rotational z-axis control) most likely to address key pathomechanics associated with PFP.

DESIGN

Systematic review: a systematic survey of RCTs.

METHODS

PubMed, CINAHL, Medline, Physiotherapy Evidence Database (PEDro) and SPORT Discus databases were searched for randomized controlled trials that addressed PFP utilizing a proximal control hip focused rehabilitation paradigm. The therapeutic exercise programs were evaluated, and each individual exercise was extracted for analysis. Quality assessments included the PEDro Scale and the Consensus on Exercise Reporting Template (CERT) was utilized to score the reporting of the interventions.

RESULTS

19 studies were included in the final analysis. 178 total exercises were extracted from the proximal hip and knee rehabilitation programs. The exercises were analyzed for the inclusion of elements that align with reported underlying biomechanical mechanisms.

CONCLUSIONS

The vast majority of the exercises were sagittal plane, concentric, non-weight bearing exercises, whereas multiplanar exercises, single limb weightbearing, and exercises where loading was directed around the longitudinal z-axis, were considerably under-represented. Current exercises for PFP utilize simplistic frameworks that lack progression into more task specific exercise, and are not reflective of the complex injury etiology.

A comparison of the effects of plyometric and virtual training on physical and functional performance: a randomized, controlled, clinical trial

BACKGROUND

This study compared the effects of plyometric training (PT) and virtual training (VT) on physical and functional performance.

METHODS

Fifty-five moderately-trained women participated in this randomized, controlled, prospective study. The subjects were randomly assigned to VT (N.=20), PT (N.=18), and control (CG, N.=17) groups. The VT was performed using the Your Body Shape Fitness Evolved 2012^™ exergame in an Xbox360/Kinetic^™ environment. The PT was based on the methods used in previous studies. Both interventions were performed 3 times per week for 8 weeks. Participants in the CG were not submitted to any type of intervention. Physical performance (fitness and athleticism levels) was assessed using the Nike+ Kinetic Training^™ exergame in an Xbox360/Kinetic^™ environment. Functional performance was assessed using the shuttle run (SR), triple hop test (THT), and six-meter timed hop test (STHT).

RESULTS

Postintervention fitness and athleticism levels were significantly greater in VT (P<0.001 and P=0.009) and in PT (P<0.001 and P=0.003) than baselines values. Only VT postintervention fitness level was significantly greater compared to CG (P=0.03). Postintervention SR values were significantly lower than baselines values in all groups (P<0.001). VT (P=0.08) and PT (P=0.006) postintervention values were significantly lower compared to CG. Postintervention THT values were significantly greater than baselines values in VT and PT (P<0.001). VT (P=0.04 - dominant limb) and PT (P=0.003 - dominant limb; and P=0.03 - non-dominant limb) postintervention values were significantly greater compared to CG. Postintervention STHT values were significantly lower than baselines values in VT (P<0.001), PT (P<0.001) and CG (P=0.01-0.02). PT postintervention dominant (P=0.01) and non-dominant (P=0.03) limb values were significantly lower compared to CG.

CONCLUSIONS

Both VT and PT are beneficial for improving physical and functional performance. Therefore, VT might be a new tool that can be used for physical exercise practice and conditioning training in moderately-trained women.

Bottom-Up Kinetic Chain in Drop Landing among University Athletes with Normal Dynamic Knee Valgus

The study investigated the influence of ankle strength and its range of motion (ROM) on knee kinematics during drop landing. Fifteen male and fifteen female university athletes with a normal range of dynamic knee valgus (DKV) (knee frontal plane projection angle: men = 3° to 8°, females = 7° to 13°) were recruited. They performed drop landing at height 30 cm and 45 cm with three-dimensional motion capture and analysis. Knee angles were compared at specific landing phases. Isokinetic ankle strength was tested at 60°/s angular velocity while the weight-bearing lunge test was conducted to evaluate ankle ROM. For males, strength for both plantarflexors and dorsiflexors were associated with knee kinematics at both heights (30 cm: r = −0.50, p = 0.03; 45 cm: r = −0.45, p = 0.05) during maximum vertical ground reaction force (MVGRF) phase. For females, ankle invertor strength and knee kinematics were associated at both 30cm (r = 0.53; p = 0.02,) and 45 cm landing heights (r = 0.49, p = 0.03), while plantarflexor strength and knee kinematics showed a significant association during initial contact (r = 0.70, p < 0.01) and MVGRF (r = 0.55, p = 0.02) phases at height 30 cm only. Male and female athletes with normal range of DKV showed a significant relationship between ankle strength and knee kinematics at specific landing phases. These relationships varied with increased landing height.

Landing Kinematics, Sports Performance, and Isokinetic Strength in Adolescent Male Volleyball Athletes: Influence of Core Training

CONTEXT

Core control and strength are important for reducing the risk of lower-extremity injury. Current evidence on the effect of core training in male adolescent athletes is limited, and other investigations into the effects of core training often emphasized core strength only.

OBJECTIVE

To examine whether core training emphasizing both control and strength of the trunk and hip would improve joint kinematics during landing, sports performance, and lower-extremity muscle strength in adolescent male volleyball athletes.

DESIGN

Single group pretest and posttest design.

SETTING

University laboratory.

PARTICIPANTS

Sixteen male participants (age: 13.4 [1] y, height: 167.8 [8.6] cm, mass: 58.6 [13.9] kg, and volleyball experience: 3.8 [1.5] y) from a Division I volleyball team at a junior high school.

MAIN OUTCOME MEASUREMENTS

Kinematics of the trunk and lower-extremity during box landing and spike jump landing tasks, volleyball-related sports performance, and isokinetic strength of hip and knee muscles were assessed before and after a 6-week core training program.

RESULTS

After training, the participants demonstrated decreased trunk flexion angle (P = .01, Cohen's d = 0.78) during the box landing task and reduced the maximum knee internal rotation angle (P = .04, Cohen's d = 0.56) during the spike jump landing task. The average isokinetic strength of hip flexors and external rotators, and knee flexors and extensors also significantly increased (P = .001, Cohen's d = 0.98; P = .04, Cohen's d = 0.57; P = .02, Cohen's d = 0.66; P = .003, Cohen's d = 0.87, respectively); however, sports performance did not show significant changes.

CONCLUSIONS

A more erect landing posture following training suggests that the core training program may be beneficial for improving core stability. The long-term effect of core training for knee injury prevention needs further investigation.

Lower Trunk Muscle Thickness Is Associated With Pain in Women With Patellofemoral Pain

OBJECTIVES

To compare trunk muscle thickness of women with and without patellofemoral pain (PFP) and to assess the association of trunk muscle thickness with self-reported pain of women with PFP.

METHODS

Forty-four women were recruited and divided into 2 groups: a PFP group (n = 22) and a pain-free group (n = 22). The thickness of the following trunk muscles was obtained by B-mode ultrasound imaging: transversus abdominis, obliquus internus (OI), obliquus externus (OE), rectus abdominis, and multifidus. Self-reported pain was measured on a visual analog scale.

RESULTS

The 44 participants were 18 to 35 years old. Women with PFP had lower thickness of the OI and OE than pain-free women, with moderate or large effect sizes ranging from -0.78 to -0.98, which was negatively related to self-reported pain correlations (r = -0.53 to -0.40). The contraction ratios of the OI and OE were also lower in women with PFP than in pain-free women (P < .05). No differences between groups were found for the transversus abdominis, multifidus, and rectus abdominis, with also no correlation with self-reported pain.

CONCLUSIONS

Lower thickness of the OI and OE is present in women with PFP, which is related to self-reported pain. These findings might help in understanding the alterations in trunk biomechanics of individuals with PFP and the mechanisms by which interventions targeting trunk muscle strength are beneficial to individuals with PFP.

Pelvic Drop Changes due to Proximal Muscle Strengthening Depend on Foot-Ankle Varus Alignment

Background

Strengthening of hip and trunk muscles can modify pelvis and hip movements. However, the varus alignment of the foot-ankle complex (FAC) may influence the effects of muscle strengthening, due to the relationship of FAC alignment with pelvic and hip kinematics. This study evaluated the effects of hip and trunk muscle strengthening on pelvis and hip kinematics during walking, in subgroups with larger and smaller values of FAC varus alignment. In addition, this study evaluated the effects of hip and trunk muscle strengthening on hip passive and active properties, in the same subgroups.

Methods

Fifty-three women, who were divided into intervention and control groups, participated in this nonrandomized controlled trial. Each group was split into two subgroups with larger and smaller values of FAC varus alignment. Hip and trunk muscle strengthening was performed three times a week for two months, with a load of 70% to 80% of one repetition maximum. Before and after strengthening, we evaluated (1) pelvis and hip excursions in the frontal and transverse planes during walking, (2) isokinetic hip passive external rotator torque, and (3) isokinetic concentric and eccentric peak torques of the hip external rotator muscles. Mixed analyses of variance (ANOVAs) were carried out for each dependent variable related to walking kinematics and isokinetic measurements (α = 0.05).

Results

The subgroup with smaller varus alignment, of the intervention group, presented a reduction in pelvic drop after strengthening (P = 0.03). The subgroup with larger varus alignment increased pelvic drop after strengthening, with a marginal significance (P = 0.06). The other kinematic excursions did not change (pelvic anterior rotation P = 0.30, hip internal rotation P = 0.54, and hip adduction P = 0.43). The intervention group showed increases in passive torque (P = 0.002), peak concentric torque (P < 0.001), and peak eccentric torque (P < 0.001), independently of FAC alignment. These results suggest that FAC varus alignment influences the effects of strengthening and should be considered when hip and trunk muscle strengthening is used to reduce pelvic drop during walking.

The Effect of Valgus Control Instruction Exercises on Pain, Strength, and Functionality in Active Females With Patellofemoral Pain Syndrome

BACKGROUND

Patellofemoral pain syndrome (PFPS) is sometimes related to excessive hip adduction and internal rotation, as well as knee valgus during weightbearing activities in females. Research on injury prevention and rehabilitation strategies has shown the positive effects of valgus control instruction (VCI) exercise programs in training.

HYPOTHESIS

A VCI program would result in a positive change in pain, eccentric hip muscle torque, and performance in females with PFPS.

STUDY DESIGN

Controlled laboratory study.

LEVEL OF EVIDENCE

Level 1.

METHODS

Sixty-four amateur female volleyball players from our university (age, 18-25 years) with PFPS and equal years of exercise experience were randomly divided into VCI (n = 32; age, 22.1 ± 5.88 years) and control (n = 32; age, 23.1 ± 6.49 years) groups. Function (single, triple, and crossover hops), strength (hip abductor and external rotators), pain (visual analog scale), and knee valgus angle (single-leg squat) were assessed at baseline and after intervention.

RESULTS

There was a significant difference before and after implementation of the VCI program with regard to pain (49.18% ↓, P = 0.000), single-leg hop test (24.62% ↑, P = 0.000), triple-hop test (23.75% ↑, P = 0.000), crossover hop test (12.88% ↑, P = 0.000), single-leg 6-m timed hop test (7.43% ↓, P = 0.000), knee dynamic valgus angle (59.48% ↓, P = 0.000), peak abductor to adductor eccentric torque ratio (14.60% ↑, P = 0.000), peak external (59.73% ↑, P = 0.023) and internal rotator (15.45% ↑, P = 0.028) eccentric torques, and the ratio of peak external to internal rotator eccentric torque (40.90% ↑, P = 0.000) ( P < 0.05).

CONCLUSION

PFPS rehabilitation and prevention programs should consider VCI exercises to decrease pain, improve strength, and increase athletes' functional performance.

CLINICAL RELEVANCE

This study investigated the effect of VCI exercises on knee valgus angle, pain, and functionality of individuals with PFPS. The VCI program improves performance, knee dynamic valgus angle, and strength in participants with PFPS. A controlled and optimal knee valgus angle during a functional task is the most important factor for injury prevention specialists. VCI training can be used as a supplemental method to prevent and treat lower extremity injury in patients with PFPS.

The Effect of Abdominal Muscle Activation Techniques on Trunk and Lower Limb Mechanics During the Single-Leg Squat Task in Females

CONTEXT

Females suffer 4 to 6 times more noncontact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established.

OBJECTIVE

To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females.

DESIGN

Interventional study setting: movement and posture laboratory.

PARTICIPANTS

A total of 13 healthy females (21.3 [0.88] y, 1.68 [0.07] m, and 58.27 [5.46] kg).

INTERVENTION

Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, and control), confirmed using surface electromyography.

MAIN OUTCOME MEASURES

Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles.

RESULTS

No differences were observed for peak lateral trunk displacement, peak hip adduction angle, or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in 4 of 6 muscles recorded.

CONCLUSION

The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

Running with injury: A study of UK novice and recreational runners and factors associated with running related injury

OBJECTIVES

To investigate the incidence and type of running related injuries in novice and recreational UK runners, and identify factors associated with injury.

DESIGN

Retrospective cross-sectional study.

METHODS

Novice and recreational runners were recruited through UK parkrun to complete a web-based survey. 1145 respondents reported information on demographics, personal characteristics, and running training characteristics (training goal, novice runners' training plans, frequency of running, running experience, running terrain). Current and previous injuries were self-reported and questions from the Oslo Sports Trauma Centre Questionnaire for overuse injury were completed. Chi-squared tests and binomial logistic regression were performed.

RESULTS

570 runners had a current injury and 86% were continuing to run despite their injury causing pain, directly affecting their performance and causing a reduction of running volume. In the first year of running, runners using a self-devised training programme were more likely to be injured compared with using a structured programme such as Couch to 5K. Running experience of over 2 years was protective (OR 0.578-0.65). Males were 1.45 times more likely to be injured. Other factors associated with current injury were wearing orthotics (OR 1.88), and lack of previous injuries in the past 12 months (OR 1.44).

CONCLUSIONS

More experienced runners have a lower rate of injury. A novice runner should use a recognised structured training programme. These results suggest that graduated loading is important for novice runners, and that load modification may be important whilst recovering from an injury, however full recovery from previous injury may prevent future injury.

National Athletic Trainers' Association Position Statement: Prevention of Anterior Cruciate Ligament Injury

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.

Effects of hip and trunk muscle strengthening on hip function and lower limb kinematics during step-down task

BACKGROUND

Strengthening of the hip and trunk muscles has the potential to change lower limb kinematic patterns, such as excessive hip medial rotation and adduction during weight-bearing tasks. This study aimed to investigate the effect of hip and trunk muscles strengthening on hip muscle performance, hip passive properties, and lower limb kinematics during step-down task in women.

METHODS

Thirty-four young women who demonstrated dynamic knee valgus during step-down were divided into two groups. The experimental group underwent three weekly sessions of strengthening exercises for eight weeks, and the control group continued their usual activities. The following evaluations were carried out: (a) isokinetic maximum concentric and eccentric work of hip lateral rotators, (b) isokinetic hip passive torque of lateral rotation and resting transverse plane position, and (c) three-dimensional kinematics of the lower limb during step-down.

FINDINGS

The strengthening program increased concentric (P<0.001) and eccentric (P<0.001) work of hip lateral rotators, and changed hip resting position toward lateral rotation (P<0.001). The intervention did not significantly change hip passive torque (P=0.089, main effect). The program reduced hip (P=0.002), thigh (P=0.024) and shank (P=0.005) adduction during step-down task. Hip, thigh and knee kinematics in transverse plane and foot kinematics in frontal plane did not significantly modify after intervention (P≥0.069, main effect).

INTERPRETATION

Hip and trunk strengthening reduced lower limb adduction during step-down. The changes in hip maximum work and resting position may have contributed to the observed kinematic effects.

Critical components of neuromuscular training to reduce ACL injury risk in female athletes: meta-regression analysis

OBJECTIVE

The aim of this study was to determine key components in neuromuscular training that optimise ACL injury reduction in female athletes using meta-regression analyses.

DESIGN

Systematic review and meta-regression.

DATA SOURCES

The literature search was performed in PubMed and EBSCO.

ELIGIBILITY CRITERIA

Inclusion criteria for the current analysis were: (1) documented the number of ACL injuries, (2) employed a neuromuscular training intervention that aimed to reduce ACL injuries, (3) had a comparison group, (4) used a prospective control study design and (5) recruited female athletes as participants. Two independent reviewers extracted studies which met the inclusion criteria. Methodological quality of included study and strength of recommendation were evaluated. Number of ACL injuries and participants in control and intervention groups, age of participants, dosage of neuromuscular training, exercise variations within neuromuscular training and status of verbal feedback were extracted.

RESULTS

The meta-regression analyses identified age of participants, dosage of neuromuscular training, exercise variations within neuromuscular training and utilisation of verbal feedback as significant predictors of ACL injury reduction (p=0.01 in fixed-effects model, p=0.03 in random-effects model). Inclusion of 1 of the 4 components in neuromuscular training could reduce ACL injury risk by 17.2-17.7% in female athletes. No significant heterogeneity and publication bias effects were detected. Strength of recommendation was rated as A (recommendation based on consistent and good-quality patient-oriented study evidence).

CONCLUSIONS

Age of participants, dosage of neuromuscular training, exercise variations within neuromuscular training and utilisation of verbal feedback are predictors that influence the optimisation of prophylactic effects of neuromuscular training and the resultant ACL injury reduction in female athletes.

EFEITO DO TREINO NEUROMUSCULAR NA ROTAÇÃO DO JOELHO DURANTE A ATERRISSAGEM EM MULHERES

Introdução: O grande índice de lesões do ligamento cruzado anterior sem envolver contato em mulheres é motivo de curiosidade entre os cientistas, pois avaliações de aterrissagem podem sugerir a predisposição ao risco dessa lesão. Neste sentido, vários protocolos de treinamento foram utilizados como intervenção e obtiveram resultados diversificados na alteração desse fator de risco. Objetivo: O objetivo deste projeto foi avaliar as possíveis alterações de rotação do joelho na aterrissagem unipodal após a intervenção de um programa de treinamento neuromuscular. Métodos: Participaram do estudo 18 mulheres com idade entre 18 e 51 anos, que foram distribuídas em dois grupos: grupo de treinamento neuromuscular de oito semanas (GTN) (n = 11) e grupo controle (GC) (n = 7). Além disso, não apresentavam lesão musculoesquelética ou dores nos membros inferiores. Cada participante realizou cinco aterrissagens unipodais válidas de uma plataforma de 40 cm de altura. O processo de captura de movimento foi realizado com 12 câmeras infravermelho do sistema OptiTrack(tm) para obter as coordenadas tridimensionais de marcadores fixados nos pontos anatômicos de interesse. Os sistemas de coordenadas locais da coxa e da perna foram definidos por meio dos respectivos marcadores fixados nos pontos anatômicos. Dessa forma, foram calculados os ângulos de rotação do joelho nos planos sagital, frontal e transverso através das sequências dos ângulos de Euler e as velocidades angulares através das formulações dos quatérnions. Resultados: Os resultados mostraram que houve um aumento na velocidade de rotação do joelho após o treinamento neuromuscular. Conclusão: Conclui-se que o treinamento neuromuscular resultou em maior velocidade de rotação no joelho nos 40 milissegundos que sucedem a aterrissagem unipodal.

Prediction of Cardiorespiratory Fitness by the Six-Minute Step Test and Its Association with Muscle Strength and Power in Sedentary Obese and Lean Young Women: A Cross-Sectional Study

Impaired cardiorespiratory fitness (CRF) is a hallmark characteristic in obese and lean sedentary young women. Peak oxygen consumption (VO_2peak) prediction from the six-minute step test (6MST) has not been established for sedentary females. It is recognized that lower-limb muscle strength and power play a key role during functional activities. The aim of this study was to investigate cardiorespiratory responses during the 6MST and CPX and to develop a predictive equation to estimate VO_2peak in both lean and obese subjects. Additionally we aim to investigate how muscle function impacts functional performance. Lean (LN = 13) and obese (OB = 18) women, aged 20–45, underwent a CPX, two 6MSTs, and isokinetic and isometric knee extensor strength and power evaluations. Regression analysis assessed the ability to predict VO_2peak from the 6MST, age and body mass index (BMI). CPX and 6MST main outcomes were compared between LN and OB and correlated with strength and power variables. CRF, functional capacity, and muscle strength and power were lower in the OB compared to LN (<0.05). During the 6MST, LN and OB reached ~90% of predicted maximal heart rate and ~80% of the VO_2peak obtained during CPX. BMI, age and number of step cycles (NSC) explained 83% of the total variance in VO_2peak. Moderate to strong correlations between VO_2peak at CPX and VO_2peak at 6MST (r = 0.86), VO_2peak at CPX and NSC (r = 0.80), as well as between VO_2peak, NSC and muscle strength and power variables were found (p<0.05). These findings indicate the 6MST, BMI and age accurately predict VO_2peak in both lean and obese young sedentary women. Muscle strength and power were related to measures of aerobic and functional performance.

Rehabilitation of Patellar Tendinopathy Using Hip Extensor Strengthening and Landing-Strategy Modification: Case Report With 6-Month Follow-up

Study Design Case report. Background Although eccentric exercises have been a cornerstone of the rehabilitation of athletes with patellar tendinopathy, the effectiveness of this intervention is sometimes less than ideal. Athletes with patellar tendinopathy have been shown to have different jump-landing patterns and lower hip extensor strength compared to asymptomatic athletes. To our knowledge, the effectiveness of an intervention addressing these impairments has not yet been investigated. Case Description The patient was a 21-year-old male volleyball athlete with a 9-month history of patellar tendon pain. Pain was measured with a visual analog scale. Disability was measured with the Victorian Institute of Sport Assessment-patella questionnaire. These assessments were conducted before and after an 8-week intervention, as well as at 6 months after the intervention. Hip and knee kinematics and kinetics during drop vertical jump and isometric strength were also measured before and after the 8-week intervention. The intervention consisted of hip extensor muscle strengthening and jump landing strategy modification training. The patient did not interrupt volleyball practice/competition during rehabilitation. Outcomes After the 8-week intervention and at 6 months postintervention, the athlete was completely asymptomatic during sports participation. This favorable clinical outcome was accompanied by a 50% increase in hip extensor moment, a 21% decrease in knee extensor moment, and a 26% decrease in patellar tendon force during jump landing measured at 8 weeks. Discussion This case report provides an example of how an 8-week intervention of hip muscle strengthening and jump-landing modification decreased pain and disability and improved jump-landing biomechanics in an athlete with patellar tendinopathy. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2015;45(11):899-909. Epub 21 Sep 2015. doi:10.2519/jospt.2015.6242.

Evaluating eccentric hip torque and trunk endurance as mediators of changes in lower limb and trunk kinematics in response to functional stabilization training in women with patellofemoral pain

BACKGROUND

Altered movement patterns of the trunk and lower limbs have been associated with patellofemoral pain (PFP). It has been assumed that increasing the strength of the hip and trunk muscles would improve lower limb and trunk kinematics in these patients. However, evidence in support of that assumption is limited.

PURPOSE

To determine whether increases in the strength of hip muscles and endurance of trunk muscles in response to functional stabilization training will mediate changes in frontal plane lower limb kinematics in patients with PFP.

STUDY DESIGN

Controlled laboratory study.

METHODS

Thirty-one female athletes were randomized to either a functional stabilization training group that emphasized strengthening of the trunk and hip muscles or a standard training group that emphasized stretching and quadriceps strengthening. Patients attended a baseline assessment session, followed by 8 weeks of intervention, and were then reassessed at the end of the intervention period. The potential mediators that were evaluated included eccentric torque of hip muscles and endurance of the trunk muscles. The outcome variables were the lower limb and trunk kinematics in the frontal plane assessed during a single-legged squat task.

RESULTS

The eccentric strength of the gluteus muscles showed a mediation effect ranging from 18% to 32% on changes to frontal plane kinematics (decreased ipsilateral trunk inclination, pelvis contralateral depression, and hip adduction excursions) observed in the functional stabilization training group after intervention.

CONCLUSION

Although the mediation effects were small, the results suggest that improvements in the strength of the gluteus muscles can influence the frontal plane movement patterns of the lower limb and trunk in women with PFP.

CLINICAL RELEVANCE

Patients with PFP might benefit from strengthening of the hip muscles to improve frontal plane lower limb and trunk kinematics during functional tasks.

ABCs of Evidence-based Anterior Cruciate Ligament Injury Prevention Strategies in Female Athletes

Anterior cruciate ligament (ACL) injury is a major concern in physically active females. Although ACL reconstruction techniques have seen significant advances in recent years, risk associated with re-injury and future osteoarthritis remains a major concern. Thus, prevention of ACL injury is a logical step to protect and preserve healthy knee joints in young athletes. The current report aims to summarize a list of evidence-based prevention strategies to reduce ACL injury in female athletes. A list of six critical principles, which come from documented, large scale clinical trial studies and further analyses, were presented with ABC format including age, biomechanics, compliance, dosage, exercise, and feedback. Also, a grade for evidence and implications of future research is noted. Finally, in the conclusion section, importance of collaborative efforts from healthcare practitioners, researchers, and personnel associated with athletics is addressed.

Effects of compliance on trunk and hip integrative neuromuscular training on hip abductor strength in female athletes

Recent studies demonstrate the link between reduced hip abductor strength and increased risk for knee injury such as patellofemoral pain syndrome in women athletes. Meta-analytic reports indicate that the efficacy of integrative neuromuscular training (INT) is associated with compliance to the prescribed programming. Thus, the purpose was to investigate the compliance effects of a trunk and hip-focused INT exercises on hip abductor strength in young women athletes. In a controlled laboratory study design, 21 high school women volleyball players (mean age = 15.6 ± 1.4 years, weight = 64.0 ± 7.4 kg, height = 171.5 ± 7.0 cm) completed isokinetic hip abductor strength testing in pre- and postintervention, which consisted of 5 phases of supervised progressive trunk and hip-focused INT exercises twice a week for 10 weeks. The compliance effects were analyzed based on the changed hip abductor strength values between pre- and postintervention and 3 different compliance groups using 1-way analysis of variance and Pearson's correlation coefficients. The participants in the high-compliance group demonstrated significant hip abductor peak torque increases compared with noncompliance group (p = 0.02), but not between moderate-compliance and noncompliance groups (p = 0.27). The moderate correlation coefficient value (r = 0.56) was recorded between the isokinetic hip abductor peak torque changes and the 3 compliance groups. Because of the observed significant effects and moderate linear association, the effectiveness of a trunk and hip-focused INT protocol to improve hip abduction strength seems dependent on compliance. Compliance of trunk and hip-focused INT is an important aspect of increasing hip abductor strength increase in young women athletes.

The effects of isolated ankle strengthening and functional balance training on strength, running mechanics, postural control and injury prevention in novice runners: design of a randomized controlled trial

BACKGROUND

Risk factors have been proposed for running injuries including (a) reduced muscular strength, (b) excessive joint movements and (c) excessive joint moments in the frontal and transverse planes. To date, many running injury prevention programs have focused on a "top down" approach to strengthen the hip musculature in the attempt to reduce movements and moments at the hip, knee, and/or ankle joints. However, running mechanics did not change when hip muscle strength increased. It could be speculated that emphasis should be placed on increasing the strength of the ankle joint for a "ground up" approach. Strengthening of the large and small muscles crossing the ankle joint is assumed to change the force distribution for these muscles and to increase the use of smaller muscles. This would be associated with a reduction of joint and insertion forces, which could have a beneficial effect on injury prevention. However, training of the ankle joint as an injury prevention strategy has not been studied. Ankle strengthening techniques include isolated strengthening or movement-related strengthening such as functional balance training. There is little knowledge about the efficacy of such training programs on strength alteration, gait or injury reduction.

METHODS/DESIGN

Novice runners will be randomly assigned to one of three groups: an isolated ankle strengthening group (strength, n = 40), a functional balance training group (balance, n = 40) or an activity-matched control group (control, n = 40). Isokinetic strength will be measured using a Biodex System 3 dynamometer. Running kinematics and kinetics will be assessed using 3D motion analysis and a force platform. Postural control will be assessed by quantifying the magnitude and temporal structure of the center of pressure trace during single leg stance on a force platform. The change pre- and post-training in isokinetic strength, running mechanics, and postural control variables will be compared following the interventions. Injuries rates will be compared between groups over 6 months.

DISCUSSION

Avoiding injury will allow individuals to enjoy the benefits of participating in aerobic activities and reduce the healthcare costs associated with running injuries.

TRIAL REGISTRATION

Current Controlled Trial NCT01900262.

Dosage effects of neuromuscular training intervention to reduce anterior cruciate ligament injuries in female athletes: meta- and sub-group analyses

BACKGROUND

Although a series of meta-analyses demonstrated neuromuscular training (NMT) is an effective intervention to reduce anterior cruciate ligament (ACL) injury in female athletes, the potential existence of a dosage effect remains unknown.

OBJECTIVE

Our objective was to systematically review previously published clinical trials and evaluate potential dosage effects of NMT for ACL injury reduction in female athletes.

DESIGN

This study took the form of a meta- and sub-group analysis.

SETTING

The keywords 'knee', 'anterior cruciate ligament', 'ACL', 'prospective', 'neuromuscular', 'training', 'female', and 'prevention' were utilized in PubMed and EBSCO host for studies published between 1995 and May 2012.

PARTICIPANTS

Inclusion criteria set for studies in the current analysis were (i) recruited female athletes as subjects, (ii) documented the number of ACL injuries, (iii) employed an NMT intervention aimed to reduce ACL injuries, (iv) had a control group, (v) used a prospective control trial design, and (vi) provided NMT session duration and frequency information.

MAIN OUTCOME MEASURES

The number of ACL injuries and female athletes in each group (control and intervention) were compared based on duration, frequency, and volume of NMT via odds ratios (ORs).

RESULTS

A total of 14 studies were reviewed. Analyses that compared the number of ACL injuries with short versus long NMT duration showed greater ACL injury reduction in female athletes who were in the long NMT duration group (OR 0.35, 95% CI 0.23-0.53, p = 0.001) than in those in the short NMT duration group (OR 0.61, 95% CI 0.41-0.90, p = 0.013). Analyses that compared single versus multi NMT frequency indicated greater ACL injury reduction in multi NMT frequency (OR 0.35, 95 % CI 0.23-0.53, p = 0.001) compared with single NMT frequency (OR 0.62, 95% CI 0.41-0.94, p = 0.024). Combining the duration and frequency of NMT programs, an inverse dose-response association emerged among low (OR 0.66, 95% CI 0.43-0.99, p = 0.045), moderate (OR 0.46, 95% CI 0.21-1.03, p = 0.059), and high (OR 0.32, 95% CI 0.19-0.52, p = 0.001) NMT volume categories.

CONCLUSIONS

The inverse dose-response association observed in the subgroup analysis suggests that the higher the NMT volume, the greater the prophylactic effectiveness of the NMT program and increased benefit in ACL injury reduction among female athletes.

Sex differences in trunk, pelvis, hip and knee kinematics and eccentric hip torque in adolescents

BACKGROUND

Adolescents have a high incidence of knee joint dysfunctions, with up to 28% of adolescents reporting knee pain. Although adolescent females have a greater incidence of knee injuries in comparison to males, few studies conducted biomechanical evaluations in this population aiming to identify sex differences. If trunk and/or lower limb biomechanical impairments are identified in female adolescents, the implementation of early interventions for injury prevention will be better justified. The purpose of this study was to compare the trunk, pelvis, hip and knee kinematics during a single-leg squat task, as well as the isokinetic eccentric hip torque, between male and female healthy adolescents.

METHODS

Forty-four healthy adolescents were divided into two groups, group of males (n=22) and group of females (n=22). Kinematics during single-leg squat were assessed using a electromagnetic tracking system. For the evaluation of eccentric hip torque in the three planes an isokinetic dynamometer was used. Group differences were assessed using a one-way multivariate analysis of variance.

FINDINGS

Results showed that adolescent females presented greater hip adduction, hip external rotation and knee abduction, as well as smaller trunk flexion during single-leg squat in comparison to males. Additionally, adolescent females showed smaller isokinetic eccentric hip torque normalized by body mass in all planes in comparison to males.

INTERPRETATION

These sex differences in terms of trunk/lower limb kinematics and eccentric hip torque generation might play an important role in the greater incidence of overuse knee injuries observed in adolescent females.

Comparison of isokinetic hip abduction and adduction peak torques and ratio between sexes

OBJECTIVE

To evaluate hip abductor and adductor peak torque outputs and compare their ratios between sexes.

DESIGN

A cross-sectional laboratory-controlled study.

SETTING

Participants visited a laboratory and performed an isokinetic hip abductor and adductor test. All participants performed 2 sets of 5 repetitions of concentric hip abduction and adduction in a standing position at 60 degrees per second. Gravity was determined as a function of joint angle relative to the horizontal plane and was corrected by normalizing the weight of the limb on an individual basis.

PARTICIPANTS

A total of 36 collegiate athletes.

INDEPENDENT VARIABLES

Sex (20 females and 16 males).

MAIN OUTCOME MEASURES

Bilateral peak hip abductor and adductor torques were measured. The 3 highest peak torque values were averaged for each subject.

RESULTS

Independent t tests were used to compare sex differences in hip abductor and adductor peak torques and the abductor:adductor peak torque ratios. Males demonstrated significantly greater hip abductor peak torque compared with females (males 1.29 ± 0.24 Nm/kg, females 1.13 ± 0.20 Nm/kg; P = 0.03). Neither hip adductor peak torque nor their ratios differed between sexes.

CONCLUSIONS

Sex differences in hip abductor strength were observed. The role of weaker hip abductors in females deserves further attention and may be a factor for higher risk of knee pathologies.

Effects of functional stabilization training on pain, function, and lower extremity biomechanics in women with patellofemoral pain: a randomized clinical trial

STUDY DESIGN

Randomized clinical trial.

OBJECTIVES

To compare the effects of functional stabilization training (FST) versus standard training on knee pain and function, lower-limb and trunk kinematics, trunk muscle endurance, and eccentric hip and knee muscle strength in women with patellofemoral pain.

BACKGROUND

A combination of hip- and knee-strengthening exercise may be more beneficial than quadriceps strengthening alone to improve pain and function in individuals with patellofemoral pain. However, there is limited evidence of the effectiveness of these exercise programs on the biomechanics of the lower extremity.

METHODS

Thirty-one women were randomized to either the FST group or standard-training group. Patients attended a baseline assessment session, followed by an 8-week intervention, and were reassessed at the end of the intervention and at 3 months after the intervention. Assessment measures were a 10-cm visual analog scale for pain, the Lower Extremity Functional Scale, and the single-leg triple-hop test. A global rating of change scale was used to measure perceived improvement. Kinematics were assessed during the single-leg squat. Outcome measures also included trunk endurance and eccentric hip and knee muscle strength assessment.

RESULTS

The patients in the FST group had less pain at the 3-month follow-up and greater global improvement and physical function at the end of the intervention compared to those in the standard-training group. Lesser ipsilateral trunk inclination, pelvis contralateral depression, hip adduction, and knee abduction, along with greater pelvis anteversion and hip flexion movement excursions during the single-leg squat, were only observed in the FST group after the intervention. Only those in the FST group had greater eccentric hip abductor and knee flexor strength, as well as greater endurance of the anterior, posterior, and lateral trunk muscles, after training.

CONCLUSION

An intervention program consisting of hip muscle strengthening and lower-limb and trunk movement control exercises was more beneficial in improving pain, physical function, kinematics, and muscle strength compared to a program of quadriceps-strengthening exercises alone.

Effect of plyometric training on lower limb biomechanics in females

OBJECTIVE

To verify the effects of plyometric training on lower limb kinematics, eccentric hip and knee torques, and functional performance.

DESIGN

Cohort study.

SETTING

Research laboratory.

PARTICIPANTS

Thirty-six females were divided into a training group (TG; n = 18) that carried out the plyometric training for 8 weeks, and a control group (CG; n = 18) that carried out no physical training.

INTERVENTIONS

Twenty-four plyometric training sessions during approximately 8 weeks with 3 sessions per week on alternate days.

MAIN OUTCOMES MEASURES

Lower limb kinematics (maximum excursion of hip adduction, hip medial rotation, and knee abduction during the single leg squat), eccentric hip (abductor, adductor, medial, and lateral rotator) isokinetic peak torques and knee (flexor and extensor) isokinetic peak torques, and functional performance (triple hop test and the 6-m timed hop test).

RESULTS

After 8 weeks, only the TG significantly reduced the values for the maximum excursion of knee abduction (P = 0.01) and hip adduction (P < 0.001). Similarly, only the TG significantly increased the eccentric hip abductor (P < 0.001) and adductor (P = 0.01) torques. Finally, only the TG significantly increased the values in the triple hop test (P < 0.001) and significantly decreased the values in the 6-m timed hop test (P < 0.001) after intervention.

CONCLUSION

Plyometric training alters lower limb kinematics and increases eccentric hip torque and functional performance, suggesting the incorporation of these exercises in preventive programs for ACL injuries.

Gender Differences in Lower Limb Kinematics During Stair Descent

The purpose of this study was to compare lower limb kinematics between genders during stair descent. Fifteen females and fifteen males who were healthy and active were included in this study. The lower limb kinematics (pelvis, femur and knee) in the coronal and transversal planes were assessed during stair descent at 30°, 40°, 50° and 60° of knee flexion. The study found that females showed greater knee medial rotation for all the knee flexion angles (P= .02−.001), greater femoral adduction (P= .01 for all variables), with exception for 30° (P= .13), and greater femoral lateral rotation at 60° (P= .04). Females also showed a trend to have greater knee valgus at all the knee flexion angles (P= .06−.11) as well as less contralateral pelvis elevation at 50° and 60° (P= .10 and .12, respectively). This study showed that females carry out the stair descent with a lower limb alignment that might predispose them to develop overuse knee injuries, such as the iliotibial band syndrome and patellofemoral pain syndrome. Further prospective investigations should be carried out to verify whether these variables are factors that could predict these knee injuries.

The influence of forefoot varus on eccentric hip torque in adolescents

Hip strength impairments have been established as risk factors for lower limb injuries. Hip muscles strength might be influenced by foot misalignments, however this has not yet been verified. Forefoot varus (FV) has been shown to cause subtalar joint hyperpronation. Subtalar hyperpronation has been associated with excessive lower limb internal rotation in weight-bearing activities. Also, subtalar hyperpronation might result in greater ground reaction force dissipation at the foot. Consequently, there would be less demand for force dissipation at the hip joint, which could reduce the capacity for hip eccentric torque in these subjects. Therefore, the purpose of this study was to determine if FV influences the eccentric hip torque generation of young subjects. Forty-four sedentary, healthy adolescents were divided into 2 groups: subjects with FV (VG, n = 22) and subjects with neutral forefoot alignment (CG, n = 22). An isokinetic dynamometer was used to assess the eccentric torque generated in hip extension and external rotation in these subjects. Group differences were assessed using a one-way multivariate analysis of variance. The VG presented smaller eccentric torque for hip extension (P = 0.014) when compared to the CG, with no difference between groups in external rotation torque (P = 0.433). These results indicate that FV influences hip eccentric torque generation of young subjects. Considering that the muscles involved in hip extension are related to the stabilization of the lumbar spine, hip and knee, these findings bring further enlightenment to the role of foot misalignments as risk factors for injuries in the lower limbs and lumbo-pelvic complex in young subjects.