Core-Muscle Training and Neuromuscular Control of the Lower Limb and Trunk

Impact of Core Training on Functional Movement Screen Scores in Athletes: A Critically Appraised Topic

CLINICAL SCENARIO

The Functional Movement Screen (FMS) is used to assess movement patterns and the risk of injury of active individuals. Current studies have found positive relationships with core training and injury prevention as well as lower limb stability, which can help improve FMS scores.

CLINICAL QUESTION

Does the implementation of a core training program have an impact on FMS scores in healthy active adults who participate in sport?

SUMMARY OF KEY FINDINGS

Literature was searched for articles that included core-focused exercises and implementation of the FMS. This resulted in 25 studies being returned, only 23 of which were published in the last 10 years. Only 7 focused on the change in FMS scores after implementation of core training. Three of these studies were included in the analysis due to the specialized athlete population. All 3 studies found that using a core training program led to significantly higher FMS scores postintervention.

CLINICAL BOTTOM LINE

There is clear evidence that core training increases FMS scores in athletes. It is important for health care providers treating athletes to consider core training to improve functional movement patterns or FMS scores in sport-specific populations.

STRENGTH OF RECOMMENDATION

Overall, there are moderate to high levels of evidence that support a grade B recommendation for core training improvements on FMS scores in athletes.

A Kinematic Study on the Use of Overhead Squat Exercise with Elastic Resistance on the Shoulder Kinetic Chain Approach

Background: The overhead squat movement involves various bodily structures, but the interaction with three-dimensional elastic resistance along the kinetic chain approach requires further understanding. Objectives: We aim to describe and compare scapular and trunk kinematics during an overhead squat under different external resistance conditions. Methods: The three-dimensional shoulder and trunk kinematics of 19 male participants were captured at 15-degree intervals, from 30 to 120 degrees, during the overhead squat movement and analyzed by phase. Results: Scapular posterior tilt was significantly affected by resistance during the UNLOAD phase (p = 0.005, η2ₚ = 0.26). Significant resistance-by-arm elevation interactions were found for scapular upward rotation during the LOAD phase (p = 0.003, η2ₚ = 0.19) and UNLOAD phase (p < 0.001, η2ₚ = 0.24); for scapular internal rotation during both the LOAD (p < 0.001, η2ₚ = 0.37) and UNLOAD phases (p = 0.006, η2 = 0.19); and for scapular posterior tilt during both the LOAD (p = 0.003, η2ₚ = 0.26) and the UNLOAD phases (p = 0.006, η2ₚ = 0.21). Trunk flexion/extension showed a significant effect on resistance during the LOAD phase (p = 0.008, η2ₚ = 0.24). Conclusions: Increasing resistance through elastic resistance significantly improves scapular kinematics via the trunk during arm elevation. This underscores the potential of the overhead squat movement as a valuable tool for assessing and treating scapular and trunk dysfunction.

Adding vibration and non-vibration foam rolling to routine soccer training alters muscle strength, flexibility, and dynamic balance in young male semi-professional soccer players: a randomized, controlled comparative study

This study aimed to examine the effects of 6-week vibration (VFR) and non-vibration foam rolling (FR) on muscle strength, hamstrings-to-quadriceps (H:Q) ratio, flexibility, and dynamic balance in soccer players. Thirty-six players were included in the study. The players were randomly assigned to either VFR (n=12), FR (n=12), or control group (CG) (n=12). The players in VFR and FR groups performed VFR or FR thrice per week for 6 weeks. The CG did not receive any intervention. Pre- and post-test assessment included muscle strength, H:Q ratio, flexibility, and dynamic balance. Dominant extremity knee flexor and non-dominant extremity knee flexor and extensor muscle strength improved in VFR and FR groups (p<0.05). Flexibility and dynamic balance improved in VFR group (p<0.05). Both 6-week VFR and FR increased muscle strength without affecting H:Q ratio. VFR was more effective than FR for improving flexibility and dynamic balance. The results can be stunning for performance enhancement.

Exercise Modalities for Improving Frontal Plane Knee and Foot Posture in Healthy Adults: A Systematic Review

Lower extremity misalignments increase the risk of chronic overload and acute injuries during sports and daily activities. Medial positioning of the knee and foot in the frontal plane is one of the key biomechanical risk factors associated with lower extremity injuries and pain. Different exercise interventions have been implemented to counteract misalignments. However, most studies have been conducted on clinical populations. Therefore, in this review, we aimed to assess the preventive effects of exercise interventions on frontal plane knee and foot posture in healthy individuals. Electronic databases (PubMed, Web of Science, PEDro) were systematically searched for original articles published between 2008 and 2024. This review included clinical trials on healthy adults (18-45 years) with or without lower extremity biomechanical misalignments, examining the effects of exercise interventions alone on knee and foot frontal plane biomechanics. Eligible studies reported at least one relevant frontal plane foot and knee biomechanical measure, such as knee valgus/abduction, medial knee displacement, foot pronation/eversion, or navicular drop. Studies involving non-exercise interventions, single-session protocols, and participants with neurological or spinal disorders, pain, or injury were excluded. A total of 35 articles with 1095 participants were included in this review. A total of 20 studies included individuals without a biomechanical misalignment, and 15 studies focused on individuals with a biomechanical misalignment. Mean values, standard deviations, and p-values were extracted from the included studies. Effect sizes and confidence intervals were then calculated to provide a quantitative presentation of the data. In conclusion, in healthy individuals without biomechanical misalignment, technique training and core muscles strengthening were most effective for improving knee valgus. Hip, core, and foot muscle strengthening reduced foot pronation in those with pronated feet, while short foot exercises improved foot positioning in individuals with flat feet. Combining lower extremity strengthening with knee position control training may reduce knee valgus in individuals with increased knee valgus.

A biokinetic approach in primary knee osteoarthritis prevention and management-exploring movement profiles and kinetic chain interactions: Current concepts

Knee osteoarthritis (OA) is a chronic disease characterized by increasing prevalence and significant physical, psychological, and economic burdens. Despite extensive research, the definition, risk factors, and effective cost-efficient treatments for knee OA remain unclear. This article aims to revisit primary knee OA, understanding its etiology, and focusing on prevention and individualized nonoperative treatment modalities. This study reviews various aspects of knee OA, including its global prevalence, economic impact, and current treatment strategies. It explores the role of mechanical loading pathways in the disease's onset, highlighting the importance of considering not only the knee but the entire kinetic chain in diagnosis and treatment. Also, it discusses knee anatomy and biomechanics during functional activities, emphasizing the role of neuromuscular control and the influence of proximal and distal joints on knee health. Current treatments focus mainly on symptom management, with limited success in disease prevention and curative interventions. This review underlines the importance of understanding the biomechanical risk factors contributing to knee OA and the necessity of individualized interventions based on biokinetic profile analysis. Knee OA management and prevention necessitate a paradigm shift from viewing it as a localized knee disease to recognizing related mechanical overloads of the human complex motion system. Identifying individual inductive elements is paramount for effective knee OA prevention, management, and rehabilitation. Future research should endeavor to identify movement profile subgroups to establish an early-stage prognosis and the impact of interventions for each group. LEVEL OF EVIDENCE V: Expert opinion based on nonsystematic review.

Effects of Exercise-Based ACL Injury Prevention Interventions on Knee Motion in Athletes: A Systematic Review and Bayesian Network Meta-Analysis

OBJECTIVE: To compare the effectiveness of injury prevention programs (IPPs) for improving high-risk knee motion patterns in the context of reducing the risk of noncontact anterior cruciate ligament injury. DESIGN: Systematic review with Bayesian network meta-analysis. DATA SOURCES: PubMed, Embase, Web of Science, Cochrane Library, and the Cumulative Index to Nursing and Allied Health Literature were searched until September 10, 2023. ELIGIBILITY CRITERIA: We included randomized controlled trials involving athletes without prior anterior cruciate ligament injury. The trials had to provide data on peak knee flexion and valgus angles, obtained from 2-leg drop vertical jump, single-leg drop vertical jump, or side-step cutting test. RESULTS: The network meta-analysis synthesized data from 22 randomized controlled trials involving 878 participants, evaluating 12 different IPPs. Results of meta-analyses indicated that, in jumping tests, the external focus instructions (mean difference [MD] = 26; credible interval [CrI] = 7.5, 44; surface under the cumulative ranking curve [SUCRA] = 0.94) and internal focus of attention (MD = 19; CrI = 0.19, 37; SUCRA = 0.81) was effective for increasing peak knee flexion, and core stability training ranked first for reducing knee valgus (MD = -4.40; CrI = -7.7, -1.1; SUCRA = 0.96). None of the IPPs revealed statistically significant effects for the cutting test. CONCLUSION: The external focus instructions and internal focus of attention increased knee flexion, while core stability exercise reduced knee valgus in jumping tests. Intervention effects were inconsistent for cutting tests. J Orthop Sports Phys Ther 2025;55(2):1-14. Epub 20 December 2024. doi:10.2519/jospt.2024.12720.

Therapeutic exercise protocol for the prevention of anterior cruciate ligament injuries in female soccer players with dynamic knee valgus (RCT)

BACKGROUND

Women's football has experienced exponential growth over the last 10 years. Its popularity is associated with an increase in ACL injuries. They constitute a major current problem as they account for 43% of the injury burden during the sports season. Despite the existing training programs, no uniform criteria have been established to design a precise intervention protocol, with specific tasks linked to women's football, nor has it been proposed to optimize the current programs.

METHODS

Randomized, double-blind, single-center clinical trial protocol scheduled for the 2025-2026 women's football season. There will be 2 groups: a group that will follow a specific ACL injury prevention protocol and a control group. The intervention period will last 12 weeks. Measurements will be taken at 3 time points. The biomechanics of the lower limbs, the jump-landing dynamics, and the pre- and post-training satisfaction of the players will be evaluated. Image capture and processing systems will be used as well as tests such as the DVJ and the LESS scoring system, among others.

DISCUSSION

This protocol aims to be one of the first to implement an ACL injury prevention program for women footballers with DKV. Despite the scarcity of research in this area, studies support beneficial effects at a preventive level.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06083818. Registered on 03 October 2023.

The Effects of a 12-Week Training Multicomponent Exercise Program on Landing Mechanics in Recreational Athletes

BACKGROUND/OBJECTIVES

This study investigated the impacts of a 12-week training program on kinetic parameters during landings in non-professional recreational athletes.

METHODS

Fifty-seven non-elite recreational athletes performed three unilateral-landing trials from a 30 cm high structure on a force platform. The following outcome measures were analyzed: the ground reaction forces at initial ground contact (PF1) and the highest value (PF2), impulse (change in the moment of force during landing), stabilization time, and ankle and knee accelerations. The ground reaction forces, momentum, and accelerations were evaluated in the vertical, medio-lateral, and anteroposterior axes. Participants were randomly assigned to two groups. The experimental group (EG) underwent a 12-week intervention, three times per week, consisting of various exercises, such as strength, eccentric, proprioceptive, whole-body vibration (WBV), and neuromuscular exercises. After 12 weeks, the same outcome measures were analyzed.

RESULTS

The effects of the training program on vertical ground reaction forces were not clear (0.3% and 0.9%, respectively). Medio-lateral (64.8%, d = 0.51) and anteroposterior (43.9%, d = 1.34) forces were probably reduced due to the training program. The stabilization time was also reduced in the experimental group (44.2%). The training program most likely decreased the vertical impulse (47.3%, d = -1.56), whereas the total ankle acceleration increased (18.4%, d = 0.79).

CONCLUSIONS

The findings reveal significant improvements in neuromuscular control and stability during landings, specifically demonstrating reduced medio-lateral forces, vertical momentum, and acceleration during monopodal landings. This study focuses on the importance of proper landing techniques in minimizing the risk of knee injuries, emphasizing the falling strategy's role in injury prevention.

Reliability and Validity of the Star Excursion Balance Test for Evaluating Dynamic Balance of Upper Extremities

BACKGROUND

Upper extremity (UE) dynamic balance is a significant physical fitness ability, which includes high-level neuromuscular proprioception, joint mobility, force, and coordination. The evaluation methods of UE dynamic balance are insufficient and lack experimental support. The Star Excursion Balance Test (SEBT) is a reliable assessment of dynamic balance and injury risk of the lower extremity.

HYPOTHESIS

The UE-SEBT is a reliable and reproducible approach for evaluating dynamic balance of UEs.

STUDY DESIGN

Observational study.

LEVEL OF EVIDENCE

Level 4.

METHODS

This cross-sectional study recruited 65 healthy adults. All participants were required to complete UE-SEBT, UE Y-balance test (UE-YBT), maximal voluntary isometric contraction (MVIC) of UE, closed kinetic chain UE stability test (CKCUEST), trunk flexor endurance test (TFET), trunk extensor endurance test (TEET), and lateral trunk endurance test (LTET). Intra- and inter-rater reliability and the correlation of UE-SEBT with other outcomes were measured.

RESULTS

Among the participants, the intra- and interoperator reliability of UE-SEBT in all directions and composite score achieved a moderate-to-excellent (intraclass correlation coefficients [ICC], 0.729-0.946) reliability. For validity, the UE-SEBT had a moderate to very strong correlation with UE-YBT (r = 0.315-0.755, P < 0.01) and a strong correlation with CKCUEST (r = 0.4-0.67, P < 0.01). Furthermore, the UE-SEBT performance showed weak-to-strong correlations with MVIC (r = 0.26-0.43, P < 0.05). UE-SEBT was also correlated with LTET, TEET, and TFET to varying degrees.

CONCLUSION

UE-SEBT has good reliability and validity to assess UE dynamic balance compared with other tests.

CLINICAL RELEVANCE

UE-SEBT can be used as a clinical assessment method to evaluate UE dynamic balance and injury prevention.

Biomechanical Analysis of Injury Risk in Two High-Altitude Landing Positions Using Xsens Inertial Units and EMG Sensors

High-altitude landing maneuvers can pose a significant injury risk, particularly when performed with different landing techniques. This study aims to compare the biomechanical parameters and injury risks associated with two landing positions-staggered foot landing and simultaneous bilateral landing-using Xsens inertial units and electromyography (EMG) sensors. A total of 26 university students (13 males, 13 females) participated in this study. Kinematic data were collected using inertial measurement units (IMUs), muscle activity was recorded with EMG, and ground reaction forces were captured using 3D force plates. The data were processed and analyzed using the AnyBody modeling system to simulate joint forces, moments, and muscle activation. This study found that simultaneous bilateral landing exhibited greater hip flexion-extension, knee flexion-extension, and ankle inversion. Vertical joint forces were also significantly higher in the hip, knee, and ankle during simultaneous bilateral landing. Staggered foot landing showed higher muscle forces in the gluteus maximus, iliopsoas, and quadriceps femoris (p < 0.001). The EMG analysis revealed significant differences in the biceps femoris (p = 0.008) and quadriceps femoris (p < 0.001). These findings suggest that simultaneous bilateral landing increases joint load, while staggered foot landing increases muscle activation, which may lead to different injury risks between the two techniques.

Influence of Physical Activity, Physical Fitness, Age, Biological Maturity and Anthropometric Variables on the Probability of Suffering Lumbar, Neck and Shoulder Pain in Spanish Adolescents from the Region of Murcia

Background: Back pain in adolescents is a common injury, mainly affecting the lumbar, cervical and sometimes shoulder region. This has been related to various factors, such as lifestyle habits or physical capacity, but no previous research has shown conclusive results. The aims of this study was to analyze the risk of suffering lumbar, neck and shoulder pain according to anthropometric and physical fitness variables, physical activity level, age and biological maturity in adolescents, as well as the influence of sex in the study results. Methods: A descriptive cross-sectional study was performed, including a sample of 2015 adolescents (boys: n = 1006, mean age = 14.41 ± 1.35 years-old; girls: n = 1009, mean age = 14.48 ± 1.41 years-old). The participants underwent an anthropometric evaluation and physical fitness tests were carried out, including a 20 m shuttle run, a counter movement jump, a horizontal jump, a 20 m sprint and push-up tests, followed by the completion of lumbar, neck and shoulder pain questionnaires. Results: Higher values in age and peak height velocity (PHV) showed an increase in the risk of suffering lumbar, neck and shoulder pain (OR = 0.79-1.55; p = 0.000-0.025). The anthropometric variables related to adiposity showed an increase in the risk of suffering back pain, with significant incidence in the lumbar region (OR = 1.32-1.60; p = 0.000); while muscle mass showed a protective effect (OR = 0.59; p = 0.000). Regarding the fitness tests, a better physical fitness seemed to protect adolescents from suffering from the analyzed back pains in the general sample and in the boys sample (OR = 0.56-1.60; p = 0.000), while in the girls sample the influence of the physical fitness was less relevant. Conclusions: Both anthropometry and physical fitness may influence the occurrence of back pain in adolescents, with some variations in their importance according to sex.

Relationship Between the Results of the Landing Error Scoring System and Trunk Muscle Thickness

Background

A landing error scoring system (LESS) is widely used to evaluate landing maneuvers. Poor landing maneuvers, such as lateral bending of the trunk, are thought to be associated with a risk of lower-extremity injury. However, no studies have examined the association between landing and trunk muscle function, which is associated with a high risk of lower-extremity injury.

Hypothesis/Purpose

This study examined whether an association exists between landing movements and a high risk of lower-extremity injury and trunk muscle function. It was hypothesized that athletes with poor activation of deep trunk muscle (transversus abdominis and internal oblique) would have lower LESS scores.

Study Design

Cross-sectional study.

Methods

The trunk muscle thickness at rest and during the plank was measured using ultrasonography. The percent of change in muscle thickness (during plank/at rest) was calculated. The LESS was measured using the Physimax. Based on the LESS scores, patients were divided into high- (LESS > 6) and low-risk (5 > LESS) groups for lower extremity injury. The relationship between the high-risk group and trunk muscle thickness was examined using a stepwise regression analysis.

Results

The high-risk group had significantly lower muscle thicknesses of the transversus abdominis (p=0.02) and transversus abdominis plus internal oblique abdominis (p=0.03) muscles during the plank. Additionally, the high-risk group showed significantly lower percent of change in muscle thickness of the internal oblique (p=0.02) and transversus abdominis plus internal oblique (p=0.01) muscles. Only the percentage of change in the thickness of the internal oblique and transverse abdominal muscles was extracted from the regression as a factor.

Conclusion

The findings indicated that athletes with landing movements and a high risk of injury, as determined based on the LESS results, had low trunk muscle function, and a relationship was observed between the change in thickness of transversus abdominis and internal oblique abdominis muscles.

Level of Evidence

3B.

[Isokinetic strength testing with different biomechanical demands on core strength: a comparison of military competitive athletes and soldiers with high occupational physical strain]

It is known that anthropometric data (weight, height, BMI, waist circumference and WHtR) and male gender are positively correlated with greater core strength, while age is negatively correlated. For competitive athletes with no significant differences in the anthropometric data stated above, there have hardly been any studies in which isometric core strength in a seated position is quantitatively compared among athletes in different sports. This study aimed to analyse different sports in well-trained athletes using military competitive sports as an example with regard to possible differences in core strength. For this purpose, Parachuting (n=28), Military Pentathlon (n=34) and Ski Platoon (n=38) groups were compared with regard to isokinetic core strength using dynamometry in seated position. In addition to the comparison of anthropometry and isokinetic results with descriptive statistics, ANOVA and Welch-ANOVA were used to compare the means of absolute and weight-adjusted core strength. It was shown that the Ski Platoon group had significantly higher flexion peak torque values than the Military Pentathlon and Parachuting groups. Even when adjusted for weight, the values were significantly higher than those measured in the Military Pentathlon group but not significantly higher than those in the Parachuting group. For extension peak torque, it was found that the Military Pentathlon group had significantly lower values than the Ski Platoon group and, in the weight-adjusted analysis, significantly lower values than the Parachuters. Using the example of competitive military sports, this study was able to show that there are significant differences in isokinetic core strength even among professional competitive athletes.This knowledge should be used to carry out detailed quantitative analyses of core strength, even in well-trained professional athletes, to find applications for prevention or to coordinate compensating exercises.

Adapted Training to Boost Upper Body Sensorimotor Control and Daily Living Functionality in Visually Impaired Baseball Players

Background and Objectives: Vision significantly contributes to postural control, balance, coordination, and body kinematics, thus deeply influencing everyday functionality. Sight-impaired subjects often show upper body anatomofunctional and kinetic chain alterations negatively impacting daily living efficiency and autonomy. The present study aimed to investigate and train, for the first time, upper body sensorimotor control in an Italian blind baseball team to boost global and segmental functionality while contemporarily prevent injuries. Materials and Methods: The whole team underwent a validated test battery using both quantitative traditional tools, such as goniometric active range of motion and muscular/functional tests, and an innovative biofeedback-based device, a Libra proprioceptive board. Consequently, a 6-week adapted training protocol was designed and leaded to improve sensorimotor control and, hence, counteract disability-related deficits and sport-specific overuse syndromes. Results: Statistically significant improvements were observed in all the investigated parameters. Noteworthy, an overall boost of global and segmental stability was detected through an orthostatic dynamic balance enhancement during the Y Balance test (p = 0.01) and trunk multiplanar control improvement on the Libra board (p = 0.01). Concurrently, the comparison of baseline vs. post-intervention outcomes revealed a consistent increase in upper body mobility (p < 0.05 for all the assessed districts), core recruitment (p = 0.01 for all the administered functional tests), and proprioceptive postural control (p = 0.01 for the Libra board validated test). Conclusions: Our findings suggest that a tailored sensorimotor training, conceived and led by an adapted physical activity kinesiologist, may effectively improve upper body functional prerequisites and global proprioceptive control, thus potentially promoting autonomy, quality of life, and physical activity/sport practice adherence in visually impaired individuals.

Reliability and validity of the medial standing overhead arm reach (SOAR) test as a measure of functional hip adduction motion

OBJECTIVE

The Posterior Standing Overhead Arm Reach (SOAR) test has been previously reported as a reliable clinical measure of closed chain hip extension motion. The proposed Medial SOAR test expands on that testing approach to provide a similar measure of functional hip adduction motion. This was a preliminary intrarater and interrater reliability and validity study of the Medial SOAR test as a measure of functional hip adduction.

DESIGN

Cross-sectional.

SETTING

University motion analysis laboratory.

PARTICIPANTS

Fifty hips were assessed in 25 (22 female) asymptomatic participants (mean age = 23.4 years, SD = 0.8).

MAIN MEASURES

Maximum hip adduction during the Medial SOAR test was measured with a standard goniometer independently by two examiners. The test was also performed using three-dimensional motion capture. The intrarater and interrater reliability of the goniometric measure was determined using intraclass correlation coefficients, and the relationship between measures obtained via goniometry and three-dimensional motion capture was assessed with Pearson correlations and Bland-Altman analysis.

RESULTS

Intrarater reliability (ICC2,3) was 0.88 (95% CI = 0.80-0.92) for Examiner 1 and 0.87 (95% CI = 0.79-0.92) for Examiner 2. The standard error of measurement and minimal detectable change were less than 3.0°. Interrater reliability demonstrated an intraclass correlation coefficient = 0.62 (95% CI = 0.28-0.79). Pearson correlations were significant with low-to-moderate associations (r = 0.49, P < 0.001; r = 0.24, P = 0.045).

CONCLUSIONS

Similar to the previously reported Posterior SOAR test, the Medial SOAR test demonstrated acceptable intrarater and interrater reliability, along with low-to-moderate associations with three-dimensional motion capture. The Medial SOAR test has the potential to provide a reliable and accurate assessment of closed chain hip adduction.

Effects of clamshell exercises in terminal extension lag after ACL reconstruction

BACKGROUND

Terminal extension lag (TEL) is common following anterior cruciate ligament reconstruction (ACLR). Clamshell exercises have been suggested as a potential intervention to address TEL, but limited research has been conducted in this area.

OBJECTIVE

This study aimed to determine the effects of Clamshell exercises in terminal extension lag after anterior cruciate ligament reconstruction.

METHODS

This randomized controlled trial included 40 participants with a history of ACLR between 1 and 3 years prior. Participants were randomly assigned to either the experimental group (Group A) or the control group (Group B). Group A received conventional exercises along with isolated hip strengthening rehabilitation, while Group B received conventional exercises without specific hip strengthening. The primary outcomes were pain levels (Numeric Pain Rating Scale), knee function (International Knee Documentation Committee scores, (IKDC)), range of motions (goniometer) and strength (sphygmomanometer).

RESULTS

In between the group comparison shows that all outcome measures (NPRS, IKDC, Goniometer, Sphygmomanometer) show significant results (p < 0.05). Within-group comparisons (paired sample t-test) show that there was a significant difference (p < 0.05) in all outcome measures of both groups.

CONCLUSION

The addition of Clamshell exercises to the rehabilitation program resulted in a significantly greater reduction in TEL compared to the control group. These findings suggest that Clamshell exercises were found to be an effective intervention for addressing TEL after ACLR.

Comparison of the effects of core stability and whole-body electromyostimulation exercises on lumbar lordosis angle and dynamic balance of sedentary people with hyperlordosis: a randomized controlled trial

BACKGROUND

Hyperlordosis is an excessive inward curvature of the lumbar spine that affects spinal function. The aim of this study was to compare the effects of core stability exercises (CSE), Whole-Body Electromyostimulation (WB-EMS), and CSE Plus on the Lumbar lordosis angle and dynamic balance in sedentary people with hyperlordosis.

METHODS

In a parallel randomized controlled trial study, seventy five untrained male adults with hyperlordosis, recruited from clinics of sports medicine and corrective exercise centers in Tehran, were randomly assigned to four groups: CSE (n = 19), WB-EMS (n = 18), CSE Plus (n = 18), and control Group (CG) (n = 20). The CSE group performed Core stability exercises, the WB-EMS group followed a Whole-body electromyostimulation combined training protocol, and the CSE Plus group engaged in a combined program protocol (CSE with the WB-EMS vest), and the control group only participated in activities of daily living. Anthropometric parameters and outcomes, including the lordosis angle and dynamic balance, were assessed before and after a six-week training program. A flexible ruler was used to measure the angle of lordosis, and the Y balance test was employed to evaluate the dynamic balance.

RESULTS

The results indicated that the lordosis angle improved in both the CSE and CSE Plus groups compared to the CG in the post-test (P = 0.017, P = 0.024). However, there were no significant differences observed between the other group pairs. Additionally, a significant difference in dynamic balance was found between the CSE Plus group and the CG in the post-test (P = 0.001), while no significant differences were observed between the other group pairs. Furthermore, within-group test results demonstrated that lumbar lordosis angle and dynamic balance variables significantly improved in the post-test compared to the pre-test stage (P < 0.05).

CONCLUSIONS

The two CSE and CSE Plus training protocols are effective as training methods for correcting certain parameters and physical deformities, including lumbar lordosis. Furthermore, the CSE Plus group demonstrated a positive impact on improving dynamic balance. Consequently, it is highly recommended that individuals with hyperlordosis can benefit from the exercises of the present study, especially CSE Plus exercises along with other rehabilitation exercises.

TRIAL REGISTRATION

The trial was registered at Thai Clinical Trials Registry (TCTR20221004011, registration date: 04/10/2022).

Randomized controlled trial study of intelligent rehabilitation training system for functional ankle instability

To investigate the intervention effect of an intelligent rehabilitation training system on patients with functional ankle instability (FAI) and to advance the research to optimise the effect of FAI rehabilitation training. Thirty-four FAI patients who participated in this trial in Guilin City from April 2023 to June 2023 were recruited as research subjects, and all subjects were randomly divided into the control group (n = 17) and the observation group (n = 17). Both groups received the conventional rehabilitation training intervention for 6 weeks, and the observation group received the additional training using the intelligent rehabilitation training system training invented by our team. Visual analogue scale (VAS), ankle active mobility, ankle muscle strength and Y-balance test (YBT) were assessed before and after treatment. Two-way repeated measures ANOVA shows that the interaction effect between time and group of VAS scores was significant (F = 35.644, P < 0.05). The interaction effect between time and group of plantar flexion mobility was significant (F = 23.948, P < 0.05), the interaction effect between time and group of dorsiflexion mobility was significant (F = 6.570, P < 0.05), the interaction effect between time and group of inversion mobility was significant (F = 8.360, P < 0.05), the interaction effect between time and group of eversion mobility was significant (F = 10.113, P < 0.05). The interaction effect between time and group of inversion muscle strength was significant (F = 18.107, P < 0.05). The interaction effect between time and group of YBT scores was significant (F = 33.324, P < 0.05). The Intelligent Rehabilitation Training System can effectively reduce pain in FAI patients, improve joint range of motion, increase inversion strength, and improve dynamic balance of the affected limb.

Effectiveness of warm-up and dynamic balance training in preventing anterior cruciate ligament injuries in college gymnasts: a 3-year prospective study for one team

BACKGROUND

The effect of trunk stability and dynamic balance warm-up exercises on physical functional improvement remains unelucidated. This study examined whether exercises could prevent anterior cruciate ligament (ACL) injury and improve trunk muscle activation and dynamic balance in gymnasts.

METHODS

This comparison study, involving gymnastics practice sessions, included 31 university gymnasts and was conducted in two periods: 1 year of observation followed by 2 years of intervention. Participants performed a trunk and dynamic balance warm-up exercise program during the intervention. The effect of exercise on the incidence of ACL injury was evaluated. In addition, the paired t-test was used to compare the Y-balance distance and the changes in muscle thickness associated with trunk muscle activation at rest and during plank.

RESULTS

ACL injury risk during the intervention was significantly lower, with a relative risk of 0.23 (P=0.02, 95% CI: 0.06-0.88). Changes in muscle thickness with activation of the transversus abdominis (P<0.01, mean difference 4.1, 95% CI: 9.97-28.07, Cohen's d=0.52), internal oblique (P<0.01, mean difference 5.2, 95% CI: 9.72-21.55, Cohen's d=0.65), and external oblique (P<0.01, mean difference 5.5, 95% CI: 20.44-39.09, Cohen's d=0.71) muscles were significantly higher during the intervention. The Y-balance distance was also significantly greater in the posterior medial reach (P<0.01, mean difference 3.3, 95% CI: 1.56-6.26, Cohen's d=0.46) during the intervention.

CONCLUSIONS

Exercise-based warm-up programs may decrease ACL injuries. It can improve physical functions, such as the rate of change in trunk muscle thickness and the posterior medial distance during Y balance.

Effects of Hypopressive Exercise on Dynamic Neuromuscular Control in Female Roller-Skaters

The effects of hypopressive exercise (HE) on dynamic balance have never been studied. We aimed to study the effects of a HE program on dynamic balance, posterior chain kinematics and expiratory peak flow on female competitive roller skaters over a 6-week training period. Twenty competitive female roller-skaters (13-22 years of age, SD 2.25) performed a 30-minute HE session once weekly before the regular roller-skating practice for 6 weeks. The HE program consisted of breathing and postural awareness exercises in addition to 5 basic HE poses performed three times each. Dynamic neuromuscular control was assessed with the Y-Balance Test (YBT), posterior back chain kinematics with the sit and reach test and peak expiratory flow rate with a digital spirometer. Paired t-test revealed significant differences between the measurement periods for all YBT leg directions and composite score (p ≤ 0.01). Significant differences were also revealed between baseline and after the intervention for the sit and reach test (p ≤ 0.01) and peak expiratory flow (p = 0.01). No differences in forced expiratory volume in the first second were found (p = 0.04). These preliminary findings suggest that a 6-week HE program could be a feasible neuromuscular option for training dynamic balance, posterior back chain kinematics and peak expiratory flow in female roller-skaters.

Lower extremity and trunk sagittal plane coordination strategies and kinetic distribution during landing in males and females

Force attenuation during landing requires coordinated motion of the ankle, knee, hip, and trunk, and strategies may differ between sexes. Sagittal plane coordination of the ankle/knee, knee/hip, and knee/trunk, and lower extremity and trunk kinematics and kinetics was compared throughout landing between 28 males and 28 females. Coordination was assessed with a modified vector coding technique and binning analysis. Total support moments (TSM), each joint's percent contribution, and timing of the TSM were compared. Females landed with less isolated knee flexion in the ankle/knee, knee/hip, and knee/trunk couplings, but more simultaneous ankle/knee flexion, less simultaneous knee flexion/hip extension, and more simultaneous trunk/knee flexion. Females landed with larger plantarflexion angles from 0-16% and smaller trunk flexion angles from 0-78%. In females, absolute TSM were larger from 0-6% and smaller from 42-100%, and normalized TSM were larger from 0-8% and 26-42%. Females had greater ankle contribution to the TSM from 14-15% and 29-35%, smaller absolute peak TSM, and the peak TSM occurred earlier. Females compensated for less isolated knee flexion with greater simultaneous ankle/knee flexion early in landing and knee/trunk flexion later in landing. Coordination and TSM differences may influence force attenuation strategies and have implications for knee injury disparity between sexes.

Comparing the Impact of Upper Body Control and Core Muscle Stabilization Training on Landing Biomechanics in Individuals with Functional Ankle Instability: A Randomized Controlled Trial

Functional ankle instability (FAI), which is characterized by recurrent ankle sprains and perceived joint instability, arises from various factors contributing to compromised biomechanical control during activities, particularly those involving landing tasks. While current research predominantly addresses lower-extremity and core stabilization interventions for FAI, the contribution of upper body control to landing biomechanics in this population remains insufficiently explored. In this study, 42 participants (19 males, 23 females) with FAI were randomly assigned to either the upper-body control training group (UBCTG) or the core muscle stabilization training group (CMSTG). The groups underwent six-week interventions, with the UBCTG receiving a dynamic core exercise program including upper body control and the CMSTG receiving static core muscle training. Pre- and post-intervention assessments encompassed electromyography of the gastrocnemius, tibialis anterior, and peroneus longus, motion analysis of the lower extremities, and ground reaction force (GRF) readings during a single-leg-jump task. Additionally, dynamic balance was assessed using the Y balance test and self-reported measurements of ankle instability were performed. The results showed similar increases in muscle activation, joint movement, and self-reported ankle instability scores within both groups. However, significant between-group differences were observed in terms of knee flexion angle, dynamic balance, and ankle instability scores, favoring the UBCTG. Although the peak vertical GRF significantly decreased and the time to peak vertical GRF increased in both groups, more changes were noted in the UBCTG. Our results demonstrated that dynamic core exercises with additional upper body control training enhance landing biomechanics, dynamic balance, and stability in individuals with FAI. Consequently, we recommend incorporating shoulder girdle exercises, proprioceptive drills, and balance exercises into dynamic core training.

The Synergetic Effect of Plyometric Compound Exercises and Transcranial Direct Current Stimulation on Balance and Physical Function

This study aimed to investigate the effects of plyometric compound exercises and Transcranial Direct Current Stimulation (tDCS) on balance and body function in healthy adults. Forty-five students enrolled at Noryangjin Y Academy in Seoul who met the research criteria were equally and randomly divided into the following groups: the Experimental Group I, Experimental Group II, and Control Group. Experimental Groups I and II received tDCS and sham tDCS for 20 min, respectively; both groups performed plyometric compound exercises for 30 min twice weekly for four weeks. The Control Group received sham tDCS for 20 min twice weekly for four weeks. Tests such as the static balance test (Functional Reach Test, FRT), dynamic balance test (Y-Balance Test, Y-BT), power test (vertical jump test and long jump test), and agility test (t-test and side-step test) were conducted on the day of the experiment, before and after the intervention. Experimental Groups I and II significantly improved in static balance, dynamic balance, power, and agility (p < 0.001), whereas the Control Group did not. Experimental Group I showed greater effects on static balance, dynamic balance, power, and agility than Experimental Group II and the Control Group (p < 0.001). In conclusion, plyometric compound exercises + tDCS intervention can be effective for an ordinary person who trains balance and body functions (power and agility); in particular, to improve exercise performance.

The Effects of FIFA 11+ Kids Prevention Program on Kinematic Risk Factors for ACL Injury in Preadolescent Female Soccer Players: A Randomized Controlled Trial

This study aimed to investigate the effects of the 8-week FIFA 11+ Kids program on kinematic risk factors for ACL injury in preadolescent female soccer players during single-leg drop landing. For this, 36 preadolescent female soccer players (10-12 years old) were randomly allocated to the FIFA 11+ Kids program and control groups (18 players per group). The intervention group performed the FIFA 11+ Kids warm-up program twice per week for 8 weeks, while the control group continued with regular warm-up. Trunk, hip, and knee peak angles (from initial ground contact to peak knee flexion) were collected during the single-leg drop landing using a 3D motion capture system. A repeated measure ANOVA was used to analyze groups over time. Significant group × time interactions were found for the peak knee flexion, with a medium effect size (p = 0.05; effect size = 0.11), and peak hip internal rotation angles, with a large effect size (p < 0.01; effect size = 0.28). We found that the FIFA 11+ Kids program was effective in improving knee flexion and hip internal rotation, likely resulting in reducing ACL stress during single-leg drop landing in young soccer players.

Weekly cumulative extracurricular core training time predicts cadet physical performance: A descriptive epidemiological study

Background

Core training can enhance athletic performance by enhancing core strength and stability. To achieve this outcome, however, a tailored training program is required; the normal military training curriculum is inadequate. The connection between cumulative weekly extracurricular training time, cumulative weekly extracurricular core training time and cadet performance is unknown.

Methods

The association between cumulative weekly extracurricular training time, cumulative weekly extracurricular core training time and performance has been discovered using a descriptive epidemiological study methodology. Questionnaires were used to collect information on personal characteristics and weekly cumulative extracurricular (core) training time, as well as the results of the Chinese Army Physical Fitness Test (C-APFT), which included 100-m dash, 5000-m run, 3000-m armed training run, 400-m steeplechase, 800 m breaststroke, horizontal bar pull-ups, 2-min sit-ups, 2-min push-ups, and hand grenade throwing. This study recruited two hundred and twenty male cadets (aged 18 to 23 years, 19.68 ± 0.91) from a military medical university.

Results

(a) The correlation between cumulative weekly extracurricular training time and C-APFT score is significant. The 100-m dash, 5000-m run, 3000-m armed training run, 400-m steeplechase, and 2-min push-ups performed the best when participants exercised for 5 to 10 h per week. (b) The number of cadets scoring good or excellent on the C-APFT improves with cumulative weekly extracurricular core training time. The recommended amount of core training for cadets per week is 120 min. (c) The average cumulative weekly extracurricular core training time was a effective predictor of performance on the 400-m steeplechase (R2 = 0.470, F = 10.641, P＜0.01), horizontal bar pull-ups (R2 = 0.238, F = 68.191, P＜0.01), 2-min sit-ups (R2 = 0.280, F = 84.710, P＜0.01), 100-m run (R2 = 0.031, F = 6.920, P＜0.01), 3000-m armed training run (R2 = 0.025, F = 5.603, P＜0.05), 2-min push-ups (R2 = 0.019, F = 4.295, P＜0.05), and hand grenade tossing (R2 = 0.025, F = 5.603, P＜0.05).

Conclusions

Active participation in extracurricular core training can improve cadets' C-APFT scores. An average cumulative weekly extracurricular training duration of 5-10 h showed the most progress, and more than 120 min per week was ideal for extracurricular core training. The amount of extracurricular time spent on core training exercises each week can be used as a predictor of the C-APFT.

single-leg medial drop landing with trunk lean includes improper body mechanics related to anterior cruciate ligament injury risk: A comparison of body mechanics between successful trials and failed trials in the drop landing test among female basketball athletes

BACKGROUND

Improper body mechanics during landing is a typical risk factor of anterior cruciate ligament injury. Drop landing test is used to evaluate landing mechanics by observing not only successful trials but also failed trials. Leaning of the trunk, which is frequently observed during failed trials, may lead to improper body mechanics related to anterior cruciate ligament injury. This study aimed to elucidate the mechanisms of landing with trunk lean that may underlie the risks of anterior cruciate ligament injury by comparing body mechanics between failed and successful trials.

METHODS

Participants were 72 female basketball athletes. The athletic task was single-leg medial drop landing, and the body mechanics was recorded by a motion capture system and force plate. Participants fixed the landing pose for ≥3 s in successful trials but failed to do so in failed trials.

FINDINGS

Failed trials included the large lean of trunk. There were significant changes in thoracic and pelvic leans at initial contact in failed trials with medial trunk lean (p < 0.05). Kinematics and kinetics during the landing phase in failed trials were associated with the risks of anterior cruciate ligament injury.

INTERPRETATION

These findings suggest that landing mechanics with trunk lean involves many biomechanical factors related to anterior cruciate ligament injury and demonstrates the inappropriate pose of trunk from the dropping phase. Exercise programs aimed at the landing manoeuver without trunk lean may contribute to reduce the risks of anterior cruciate ligament injury in female basketball athletes.

The Effect of McGill Core Stability Training on Movement Patterns, Shooting Accuracy, and Throwing Performance in Male Basketball Players: A Randomized Controlled Trial

CONTEXT

Core stability training has been recommended as a vital element in improving movement's pattern and athletic performance. The main objective of this study was to investigate the effect of 12-week McGill core stability training on movement patterns, shooting accuracy, and throwing performance.

DESIGN

Randomized controlled clinical trial.

SETTING

University research laboratory.

METHODS

Forty male basketball players were randomly assigned to experimental and control groups. The experimental group completed 12-week McGill core stability training, while the control group completed routine exercise training. Patterns of functional movements was measured through functional movement screen (FMS), shooting accuracy measured by static 3-point shooting (S3P) and dynamic 60-second 3-point shooting test, and throwing performance measured by Functional Throwing Performance Index.

RESULTS

Comparison revealed that regardless of received training, after 12 weeks both groups showed significant improvement in all outcome measures. However, experimental group had significantly higher post test scores in FMS (P = .02), S3P (P = .007), and dynamic 60-second 3-point shooting test (P = .01). For Functional Throwing Performance Index, there was no group differences (P = .96). The results of follow-up assessments showed for all measurements including FMS (P = .03), S3P (P = .004), dynamic 60-second 3-point shooting test (P < .001), and Functional Throwing Performance Index (P = .005); experimental group had higher scores than the control group.

CONCLUSIONS

According to the results, implementing McGill core stability training in basketball routine training would be advisable since significant improvement can be obtained in the measured parameters.

Preseason Prognostic Factors for Injuries and Match Loss in Collision Sports: A Systematic Review

This study aimed to identify which preseason factors had strong evidence of risks for physical injury during the season of collision sports including rugby, American football, and Australian rules football using qualitative synthesis. Pubmed, EMBASE, MEDLINE, SPORTDiscus, Scopus, and the Cochrane Library were reviewed. Eligibility criteria for selecting studies were: studies involving the collision sports; prospective cohort studies; and studies with outcomes of relative risks, odds ratios, and correlations between players' preseason conditions and injury during the season. The risk of bias based on the Scottish Intercollegiate Guidelines Network quality checklists for cohort studies was assessed in 57 studies. The current study identified strong evidence that 1) anthropometric characteristics (body mass index and estimated mass moment of inertia of the body around a horizontal axis through the ankle), which are calculated with weight and height; 2) physical function, in particular for the trunk and lower limb (trunk-flexion hold and wall-sit hold); and 3) Oswestry Disability Index disability, which is a patient-reported outcome measure for disability due to low back pain, were positive prognostic factors for injury during the collision sports season, regardless of playing experience.

The Relationship between Ergometric Treadmill or Bicycle Performance and Isokinetic Trunk Strength - a Retrospective Analysis

The relationship between trunk strength and athletic performance is well known. In the past, trunk strength and athletic performance were measured in field tests. Previous studies encouraged sport-specific analyses. The goal of this study was to investigate whether there is a relation between ergometrically measured treadmill or bicycle endurance and isokinetic trunk strength. This retrospective analysis included 1334 bicycle and 1838 treadmill ergometry examinations in 1149 subjects. Bicycle and treadmill ergometer performance were analysed in relation to isokinetic trunk strength. Statistics were performed by Pearson correlation and mixed or generalised linear models. Higher treadmill and bicycle power correlated with higher isokinetic trunk strength, with highest absolute trunk strength in the treadmill group. For both running and cycling endurance, a positive correlation with trunk strength could be quantified in regression models. Increased ergometry endurance and lower flexion/extension ratios are connected weakly. Ergometry performance had the strongest correlation with extension trunk strength (r=0.312-0.398 for bicycle ergometry and r=0.168-0.229 for treadmill ergometry, p<0.001). We encourage prospective studies using both kinds of ergometry to evaluate the effect of trunk strengthening to enhance sport-specific endurance performance. Weight-adapted trunk strength values showed overall greater correlation to trunk strength and we recommend the use of weight-adapted values.

Assessing the Association of Shoulder Pain Risk with Physical Fitness in Badminton Players at National Tournament Level

Background: Shoulder pain which affects sports performance and activities of daily life, is a common musculoskeletal problem experienced by badminton players. Objectives: This study aimed to identify the association of shoulder pain with physical fitness in elite university badminton players participating in the national tournament via medical check-ups. Methods: Physical fitness evaluations were performed among fifty-two 18 - 22 years old university badminton players participating in the national tournament. Handgrip strength, heel buttock distance, angle of straight leg raise, single leg stance, shoulder range of motion, and trunk range of motion were assessed. The prevalence of present shoulder pain was described. Multivariable logistic regression was used to examine the association of present shoulder pain with physical fitness. Results: Sixteen badminton players (30.8%) sustained present shoulder pain related to badminton. Dominant trunk rotation (adjusted OR: 0.91, 95% CI: 0.84 - 0.99, P-value = 0.028) and single leg stance of the nondominant leg (adjusted OR: 0.97, 95% CI: 0.94 - 1.00, P-value = 0.048) were significantly associated with the presence of present shoulder pain. Conclusions: Decreased trunk rotation and deficit in single-leg stance balance might be potential risk factors associated with physical fitness for shoulder pain in university badminton players at national tournament level. These findings can help draw the attention of badminton coaches, players, and team members to facilitate physical fitness promotion for badminton pain/injury prevention.

Effect of combining eight weeks of neuromuscular training with dual cognitive tasks on landing mechanics in futsal players with knee ligament dominance defect: a randomized controlled trial

BACKGROUND

The performing of jump and landing in futsal simultaneous with divided attention is one of the most common mechanisms of non-contact anterior cruciate ligament (ACL) injury. Neuromuscular training has effectively reduced the risk of ACL injury, but the effect of neurocognitive training has received less attention. This study investigated the effect of combining 8 weeks of neuromuscular training with dual cognitive tasks on the landing mechanics of futsal players with knee ligament dominance defects.

METHODS

Thirty male futsal players (mean ± SD: age: 21.86 ± 3.27 years) with knee ligament dominance defects were purposefully identified by the tuck jump test and were randomly divided into the intervention and the control group. The intervention group performed dual task (DT) training for three weekly sessions for 8 weeks and 60 min each, while the control group only did activities of daily living. During the drop vertical jump test, 2D landing kinematics in two moments of initial contact (IC) and full flexion (FF) were assessed. Data were analyzed by means of 2 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of (α ≤ 0.05).

RESULTS

A significant improvement was observed in the intervention group compared to the control group for the dynamic knee valgus at IC (F1,28 = 6.33; P = 0.02, ES = 0.31) and FF (F1,28 = 13.47; P = 0.003, ES = 0.49), knee flexion at IC (F1,28 = 20.08; P = 0.001, ES = 0.41) and FF (F1,28 = 13.67; P = 0.001, ES = 0.32), ankle dorsiflexion at IC (F1,28 = 37.17; P = 0.001, ES = 0.72) and FF (F1,28 = 14.52; P = 0.002, ES = 0.50), and trunk flexion at FF (F1,28 = 20.48; P = 0.001, ES = 0.59) angles. Changes in the trunk flexion at IC (F1,28 = 0.54; P = 0.47, ES = 0.03) and trunk lateral flexion at IC (F1,28 = 0.006; P = 0.93, ES = 0.00) and FF (F1,28 = 2.44; P = 0.141, ES = 0.148) angles were not statistically significant.

CONCLUSIONS

DT training compared to the control group improved landing mechanics in futsal players with knee ligament dominance defects.

TRIAL REGISTRATION

Current Controlled Trials using the IRCT website with ID number IRCT20210602051477N1 prospectively registered on 20/06/2021.

Acute circulatory and femoral hemodynamic responses induced by standing core exercise at different rotational cadence: a crossover study

Background

Core exercise is often adopted as an adjunct in maintaining musculoskeletal health in rehabilitation; we previously showed that standing core rotational exercise improves femoral blood flow after training. This study aimed to investigate the effects of different rotational cadences on circulatory and hemodynamic responses after acute standing core exercise.

Methods

Sixteen healthy male adults (22 ± 1 yrs) were randomly assigned to participate in two 30-min standing core exercises of fast (75 rpm, FC) and slow cadence (20 rpm, SC) sessions after completing an acute bout of seated knee extension exercise session (KE) (80% of 1 repetition maximum × 12 repetitions × 3 sets). Impedance cardiography-derived circulatory responses and femoral hemodynamics by ultrasound imaging were measured pre- and 30, and 60 min post-exercise.

Results

KE acutely increased post-exercise cardiac output at 30 min (p = 0.008) and heart rate at 30 min (p = 0.04) and 60 min (p = 0.01), yet brachial blood pressure did not change. Systemic vascular resistance was significantly lower after FC and KE at 30 min (p = 0.008) and 60 (p = 0.04) min, respectively, compared with the baseline. In addition, KE acutely decreased post-exercise arterial stiffness (p = 0.05) at 30 min, increased femoral conductance (p = 0.03, p < 0.001), and blood flow (p = 0.009, p < 0.001) at 30 and 60 min. No significant changes were observed in absolute femoral blood flow after FC and SC, except that FC significantly increased relative femoral blood flow (p = 0.007) and conductance (p = 0.005). Post-exercise femoral diameter significantly increased in KE at 30 (p = 0.03) and 60 min (p = 0.01), but not in core exercise.

Conclusion

Our results suggest that standing core exercise elicits circulatory and hemodynamic changes only when the rotational cadence is set at a faster cadence, which provides preliminary scientific evidence for its use in exercise programs.

Effect of Core Stability Training on Unstable Support Surfaces in Postoperative Rehabilitation of Thoracolumbar Vertebral Compression Fractures in the Elderly

Objective

Thoracolumbar vertebral compression fractures (TVCF) are caused by anterior flexion or vertical downward violence to the spine (Sezer et al. 2021). This study is aimed at investigating the effect of core stability training (CST) on unstable support surfaces in the postoperative rehabilitation of TVCF in the elderly. Methods. Ninety-eight patients with TVCF who underwent surgical treatment in our hospital from July 2021 to April 2022 were selected as study subjects. Then, they were divided into a research group receiving unstable support surface CST and a control group with conventional rehabilitation training according to the random number table method. Before and after the training, the X-ray machine was positioned and the anterior margin and middle height ratio and the posterior convex Cobb angle of the injured vertebrae were observed, and the balance detector was used to detect patients' eye opening and closing trajectory length, Romberg rate, and to perform gait test. Patients' pain, lumbar spine function, and quality of life were subsequently assessed using the Visual Analogue Scale (VAS), Oswestry Dysfunction Index (ODI), Generic Quality of Life Inventory-74 (GQOL-74), and patient satisfaction with rehabilitation was investigated. Results. After rehabilitation training, there was no statistically marked difference in eye-opening trajectory length between both groups (P > 0.05). The research group had higher scores than the control group in all dimensions of the anterior border of the injured vertebra, middle height ratio, and GQOL-74, while the posterior convex Cobb angle, closed-eye trajectory length, Romberg rate, VAS, and ODI were lower than the control group (P < 0.05). The research group also revealed better gait improvement and higher rehabilitation satisfaction than the control group after training (P < 0.05).

Conclusion

Unstable support surface CST can effectively improve postoperative vertebral body rehabilitation, balance function, gait, pain conditions, and lumbar spine function in elderly TVCF patients, and enhance their quality of life and rehabilitation satisfaction. This trial is registered with ChiCTR2000014547.

The Effectiveness of Trunk and Balance Warm-up Exercises in Prevention, Severity, and Length of Limitation From Overuse and Acute Lower Limb Injuries in Male Volleyball Players

Background

Injuries in volleyball players are most common in the ankles and knees. Many volleyball players suffer from overuse injuries because of the strain placed on the lower extremities from repeated jumping. A characteristic of players who are most at risk for lower extremity injuries is the tendency to display trunk instability during landing, such as lateral flexion and rotation. Research has shown the effectiveness of exercise-based warm-up interventions for acute volleyball injuries. However, comprehensive analyses on the use of lower extremity, trunk, and balance programs to prevent overuse injuries are lacking.

Purpose

To examine the effects of trunk and balance warm-up exercises on the prevention, severity, and length of limitation of overuse and acute lower limb injuries in male volleyball players.

Study Design

Prospective, single-cohort study.

Methods

This study involved the 2019 (control group) and 2021 (intervention group) male volleyball teams. The control and intervention groups were on the same team; however, seven players joined in 2021 through a sports referral program through which different players are recruited. Measurements included injury incidence rate, injury severity, and injury burden. The intervention involved the addition of trunk and balance exercises during the 2021 season.

Results

There was no significant difference in injury incidence rates between groups. Injury severity decreased by 3.7 days for overuse injuries (p=0.04). Injury burden decreased by 11.8 (days/1000 player hours) overall and by 7.1 (days/1000 player hours) for overuse injuries.

Conclusion

The results show that an exercise-based warm-up aimed at improving trunk posture during landing did not reduce the incidence rate of injury in men's volleyball. However, the addition of this warm-up did significantly reduce the severity of overuse injury.

Level of Evidence

Level 3B.

Effects of a Groin Pain Prevention Program in Male High School Soccer Players: A Cluster-Randomized Controlled Trial

Background

Groin pain is frequently reported by soccer players. A prevention program incorporating the Copenhagen adduction exercise (CAE) has been shown effective in decreasing adductor muscle injury in semi-professional soccer players. However, the effect of such programs on groin pain in high school soccer players is unknown. No reports have examined the effects of combining the CAE with other targeted exercises such as the Nordic hamstrings exercise (NHE).

Purpose

To evaluate the preventative effects of exercise on groin pain in high school soccer players in three groups comprising NHE alone, combined NHE and CAE, and a control group.

Design

Randomized Controlled Clinical Trial.

Methods

A cluster randomized controlled trial spanning 16 weeks was conducted on 202 high school soccer players from seven high schools in a Japanese under 18 Soccer League. Players were allocated to either group A (three schools, 66 players) receiving the CAE alone, or group B (two schools, 73 players) receiving the CAE and NHE, or control group C (two schools, 63 players) who performed their usual training. This study compared the number of injuries, injury rate, and severity of the injury of groin pain in these three groups.

Results

The number of players injured was less in group B (4 players) compared to C (18 players), and time-lost to soccer was less in groups A (6 players) and B (3 players) compared to group C (16 players). Injury rates were significantly lower in groups A and B, with the relative risk of injury compared to group C of 0.42 (95% CI 0.19% to 0.90%) in group A and 0.19 (95% CI 0.07 to 0.54) in group B.

Conclusion

A 16-week program incorporating the CAE in training sessions in high school soccer players reduced the incidence of groin pain and which may be related to injury severity according to time -lost to soccer, however the combination of both the CAE and NHE may be more effective than the CAE alone.

Level of Evidence

2b.

Osgood-Schlatter Disease: Appearance, Diagnosis and Treatment: A Narrative Review

Osgood-Schlatter disease is the most common osteochondritis of the lower limb in sport-practicing children and adolescents. Its manifestation usually coincides with the appearance of the secondary ossification center of the tibia and is linked to the practice of sports with an explosive component. In the present study, a review of the factors related to its appearance, diagnosis and treatment was carried out. Its appearance seems to be multifactorial and related to multiple morphological, functional, mechanical and environmental factors. Given all the above, risk factor reduction and prevention seem the most logical strategies to effectively prevent the appearance of the condition. In addition, it is essential to create prevention programs that can be objectively assessed and would allow to stop the progress of the pathology, particularly in those sports where high forces are generated on the insertion zone of the patellar tendon at sensitive ages. More studies are needed to clarify which type of treatment is the most appropriate—specific exercises or the usual care treatment.

The effectiveness of injury prevention programs that include core stability exercises in reducing the incidence of knee injury among soccer players: A systematic review and meta-analysis

BACKGROUND: The knee is one of the most common sites of injuries among soccer players. The incidence of knee injuries can be reduced by improving the neuromuscular control and core stability. OBJECTIVE: This study aimed to evaluate the effectiveness of injury prevention programs that include core stability exercises in reducing the incidence of knee injuries among soccer players. METHODS: Data were obtained from different databases (1985–2021). Only randomized controlled trials that used injury prevention programs that include core stability exercise to prevent knee injuries were included. The keywords used during the search were ‘knee injuries’, ‘core stability exercises’, ‘FIFA 11+’, ‘prevention of knee injuries’, ‘anterior cruciate ligament injury’ and variations of these search terms. RESULTS: The pooled results of 7828 soccer players and 863700 exposure h showed an overall injury reduction of 56% per 1000 h of exposure in the intervention group compared to the control group with an injury risk ratio of 0.44 (95% CI 0.321–0.619; P= 0.001). CONCLUSIONS: Injury prevention programs that include core stability exercises reduce knee injury rates among soccer players by 56% (46% in male and 65% in female soccer players).

Strength and Power-Related Measures in Assessing Core Muscle Performance in Sport and Rehabilitation

While force-velocity-power characteristics of resistance exercises, such as bench presses and squats, have been well documented, little attention has been paid to load, force, and power-velocity relationships in exercises engaging core muscles. Given that power produced during lifting tasks or trunk rotations plays an important role in most sport-specific and daily life activities, its measurement should represent an important part of the test battery in both athletes and the general population. The aim of this scoping review was 1) to map the literature related to testing methods assessing core muscle strength and stability in sport and rehabilitation, chiefly studies with particular focus on force-velocity-power characteristics of exercises involving the use of core muscles, 2) and to identify gaps in existing studies and suggest further research in this field. The literature search was conducted on Cochrane Library databases, Scopus, Web of Science, PubMed and MEDLINE, which was completed by SpringerLink, Google Scholar and Elsevier. The inclusion criteria were met in 37 articles. Results revealed that among a variety of studies investigating the core stability and core strength in sport and rehabilitation, only few of them analyzed force-velocity-power characteristics of exercises involving the use of core muscles. Most of them evaluated maximal isometric strength of the core and its endurance. However, there are some studies that assessed muscle power during lifting tasks at different loads performed either with free weights or using the Smith machine. Similarly, power and velocity were assessed during trunk rotations performed with different weights when standing or sitting. Nevertheless, there is still scant research investigating the power-velocity and force-velocity relationship during exercises engaging core muscles in able-bodied and para athletes with different demands on stability and strength of the core. Therefore, more research is needed to address this gap in the literature and aim research at assessing strength and power-related measures within cross-sectional and intervention studies. A better understanding of the power-force-velocity profiles during exercises with high demands on the core musculature has implications for designing sport training and rehabilitation programs for enhancement of athletes' performance and/or decrease their risk of back pain.

Effect of Respiratory Training Combined with Core Muscle Training on the Overall Motor Function and Activities of Daily Living of Patients with Early and Midterm Stroke

Stroke is a cerebral ischemic or hemorrhagic disease with sudden onset and rapid progress. To analyze the effect of respiratory training combined with core muscle training on the overall motor function and activities of daily living of patients with early and midterm stroke, 90 cases with early and midterm stroke admitted to the neurological department of our hospital from April 2018 to April 2019 were chosen as the research objects. According to the odd or even hospitalization numbers, they were equally divided into the study group and the reference group. Both groups received basic drug treatment. On this basis, the reference group was given routine rehabilitation training, while the study group was given respiratory training combined with core muscle training. The clinical indexes of both groups before and after intervention were evaluated to analyze the effect of different training methods on the rehabilitation of patients with early and midterm stroke. There was no significant difference in gender ratio, average age, average BMI, average course of disease, stroke types, MAS grading, location of limb dysfunction, and combined disease between the two groups (P < 0.05). The total clinical effective rate of the study group after intervention was obviously higher than that of the reference group (P < 0.05). The MoCA scores of both groups after intervention were obviously higher than those before intervention, and the score of the study group after intervention was obviously higher than that of the reference group. The scores of limb motor function, activities of daily living, and balance function at T₂, T₃, and T₄ in the study group were obviously higher than those in the reference group (P < 0.001). At 4 and 8 weeks after intervention, the 10 m MWS of the study group was obviously higher than that of the reference group (P < 0.001), while the TUGT was obviously lower (P < 0.001). Respiratory training combined with core muscle training can obviously improve the activities of daily living, cognitive function, and limb motor function of patients with early and midterm stroke, which is worth popularizing and using.

Injury Prevalence of the Lower Limbs in Handball Players: A Systematic Review

Lower limb injuries are frequent in handball and a serious hindrance to athletic performance. The aim of this systematic review was to synthesize the available research on the prevalence of lower limb injuries in handball players according to sex and competitive level. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, 19 studies were selected after a systematic search and selection process of three digital databases: Scopus, PubMed, and Web of Science. Furthermore, a study quality analysis using an ‘Extension for Sports Injury and Illness Surveillance of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE-SIIS)’ was carried out. The sample consisted of 7110 male and female handball players registering 4483 injuries in their lower limbs. The results showed a high incidence of knee injuries (30.23%) and ankle injuries (24.80%), especially in the ligaments, such as the talofibular and the anterior cruciate ligaments. Considering sex and competitive level, knee injuries accounted for 47.02% of injuries among women, while among men, ankle injuries were most prevalent (34.22%) in international competitions. Additionally, the most common cause of injuries was trauma (85.61%). The findings highlighted that the prevalence of lower limb injuries varies greatly according to the characteristics of the sample and injury. Therefore, the study underlines the importance that sports practitioners (physical trainers, readapters, and physiotherapists) adapt training protocols to reduce injury incidence in the most affected body areas or tissues.

Effect of Strength Training on Jump-Landing Biomechanics in Adolescent Females

BACKGROUND

Sex-based differences in neuromuscular characteristics relevant to anterior cruciate ligament (ACL) injury risk may arise as compensation for divergent strength development during puberty. Strength training during this period may prevent the development of these undesirable neuromuscular characteristics.

HYPOTHESIS

Strength-trained middle school girls will have improved jump-landing biomechanics compared with control participants.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Maximum voluntary isometric contraction in hip extension and abduction and knee extension and flexion as well as Landing Error Scoring System (LESS) scores were collected for healthy female middle school students of grades 6 to 8. Strength-training participants (STR: N = 30; height, 1.63 ± 0.07 m; mass, 48.1 ± 7.6 kg; age, 12.5 ± 1.0 y) were matched with control participants (CON: N = 30; height, 1.60 ± 0.09 m; mass, 47.2 ± 8.9 kg; age, 12.6 ± 0.9 y). The training consisted of a 6-month strength-training program administered through a gym class curriculum that targeted the lower extremity. A repeated-measures mixed-model analysis of variance was used for comparisons between groups and across time (α = 0.05). Stepwise linear regression was used to examine the relationship between strength change and LESS score change.

RESULTS

Strength values (N·m/kg) increased across time and to a greater degree in STR for hip extension (baseline 3.98 ± 1.15 vs follow-up 4.77 ± 1.80), hip abduction (4.22 ± 1.09 vs 5.13 ± 2.55), and knee flexion (3.27 ± 0.62 vs 3.64 ± 1.40) compared with CON. LESS grades significantly decreased across time in STR (5.58 ± 1.21 vs 4.86 ± 1.44) and were significantly lower than CON (5.98 ± 1.42) at follow-up (P < 0.001). The change in hip extension and knee extension strength explained 67% of the variance (P < 0.001) in the LESS change score in the STR group.

CONCLUSION

A school-based strength-training program that focused on hip and knee musculature significantly improved jump-landing biomechanics (as determined by LESS) relevant to ACL injury risk. Further investigation using different strength-training approaches in this age group is warranted.

CLINICAL RELEVANCE

Strength training during adolescence holds promise as an injury prevention program. The use of a school-based approach is novel and may represent a robust opportunity for injury prevention programs, as physical education class is often mandatory in this age group.

Effects of a 6-week core stabilization training program on dynamic balance and trunk stabilization endurance of horse riders

The purpose of this study was to examine the effectiveness of a 6-week core stabilization training program (CSTP) in improving dynamic balance and back-extensor endurance of horse riders; and develop a measurement tool in assessing the dynamic postural stabilization endurance for horse riders. Twelve male horse riders (age: 23.58 ± 1.93 years; height: 165.09 ± 4.60 cm; weight: 56.53 ± 4.75 kg; experience in horse racing: 1.75 ± 0.34 years) completed 12 training sessions in 6 weeks. Subjects performed the CSTP with two progressions. CSTP started with the basic consciousness activation exercises, and then eliminated visual feedback in dynamic balance task on unstable surfaces and finished with switching the center of gravity. Moderate-to-large difference was demonstrated in the Y-Balance test scores for right leg (102.81 ± 8.32 vs 106.471 ± 4.35 cm, d = 0.55, 95% CL 0.00 to 1.08) and left leg (102.04 ± 3.20 vs 106.29 ± 3.62 cm, d = 1.25, 95% CL 0.41 to 2.05) following 6 weeks CSTP. However, trivial to small differences was reported between left and right leg in pre (d = 0.12, 95% CL − 0.49 to 0.73) and post 6-week CSTP (d = 0.04, 95% CL − 0.69 to 0.78). Biering–Sørensen test (BST) shows largely greater performance after 6-week CSTP (98.3 ± 30.1 vs 131.8 ± 19.0 s, d = 1.33, 95% CL 0.54–2.09). A novel measurement, Swiss ball four-point kneeling test was shown to be correlated with the change in BST (r = 0.633).

The relationship between lower limb maximal and explosive strength and change of direction ability: Comparison of basketball and tennis players, and long-distance runners

Change-of-direction (CoD) ability is an important determinant of athletic performance. Muscle strength is among the most important determinants of CoD ability. However, previous studies investigating the relationship between CoD ability and muscle strength focused mostly on flexor and extensor muscle groups, or used multi-joint exercises, such as jumps, squats or mid-thigh pull. The purpose of the present study was to investigate the relationship between CoD ability and strength of ankle, knee, hip and trunk maximal and explosive strength. The participants (n = 327), consisting of male and female basketball players, tennis players and long-distance runners completed isometric strength assessments and CoD testing (90° and 180° turn tests). The times of both CoD tests were associated with muscle strength (peak torques and the rate of torque development variables), with correlation coefficients being mostly weak to moderate (r = 0.2–0.6). Strength variables explained 33%, 62% and 48% of the variance in the 90° turn task, and 42%, 36% and 59% of the variance in the 180° turn task, in basketball players, long-distance runners and tennis players, respectively. Hip and trunk muscle strength variables were the most prevalent in the regression models, especially hip adduction and abduction strength. Our results suggest that the strength of several lower limb muscles, in particular of the hip abductors and adductors, and trunk muscles, but also hip rotators, extensors and flexors, as well as knee and ankle flexors and extensors should be considered when aiming to improve CoD performance.

Impact of Three Strengthening Exercises on Dynamic Knee Valgus and Balance with Poor Knee Control among Young Football Players: A Randomized Controlled Trial

The observed dynamic knee valgus and the limited dynamic balance described in the literature are modifiable risk factors for injuries in athletes. Therefore, identification and appropriate prevention are crucial in managing the development of young athletes. The aim of the study was to assess the effectiveness of three exercises strengthening the muscles: gluteal medius, popliteal and tibialis posterior to reduce dynamic knee valgus and improve the dynamic balance of the lower limbs in young football players with poor knee control. A total of 134 footballers were assessed for eligibility, and finally 45 participants (age 12–15) met the inclusion criteria. Participants were assessed with 2D video kinematic analysis during single-leg squats to assess the knee valgus angles and the dynamic balance (Y-Balance Test). No significant interactions between groups (Control and Exercise) and time (baseline and after 6 week) were noted for dynamic valgus for the left and right knee (p > 0.05). For the dynamic balance, there were statistically significant results, but not clinically relevant for anterior, posteromedial, and composite direction for the right lower limbs and for the anterior direction for left lower limbs in the exercise group. However, there were no significant differences (p > 0.05) in all of the YBT scores for both lower limbs between groups. This study demonstrated that there were no statistically significant differences in dynamic knee valgus angles and dynamic balance values after 6 weeks of exercise program in young footballers with poor knee control. Future randomized trials should focus on more comprehensive exercises, where possible using biofeedback methods to improve knee kinematics.

Effect of a simple core muscle training program on trunk muscle strength and neuromuscular control among pediatric soccer players

Purpose

The purpose of this study was to examine the effect of simple core muscle training (CMT) program on trunk muscle strength and neuromuscular control among pediatric athletes.

Methods

Forty-nine male soccer players (mean age, 10.8 years) participated. The CMT program had three components (bench, side bench, and Nordic hamstrings) and was performed at least three times weekly for a year. Trunk flexion/extension muscle strength and the K/H ratio (determined by dividing knee separation distance by hip separation distance during drop-jump test and used as an index of lower limb valgus alignment) were measured, and the Y balance test (YBT) was performed before and after intervention. This study did not include the pure control group among the same team. To consider the effect of CMT on trunk muscle strength due to physical growth, we used the data of trunk muscle strength from the local cohort study previously conducted in our institution. One hundred participants who matched the age, height, body weight, and body mass index of the training group was designated as a control group.

Results

In the training group, the trunk flexion/extension strength significantly increased at 6 months (p < 0.001, p < 0.001, respectively) and 12 months (p < 0.001, p < 0.001, respectively) compared to initial value. The K/H ratio at initial contact and maximum knee flexion phase significantly increased at 6 months (p < 0.001 and p < 0.001, respectively); however, it did not increase at 12 months (p = 0.384 and p = 0.070, respectively) compared to the initial value. In the YBT, the maximized reach distance in each direction significantly increased after intervention on both the dominant and non-dominant sides, except in the posteromedial direction on the non-dominant foot. Compared to the control group, although there was no significant difference in trunk flexion/extension strength at baseline (p = 0.141 and p = 0.390, respectively), the training group showed significantly higher trunk flexion/extension muscle strength at 12 months (p < 0.001 and p < 0.001, respectively).

Conclusion

The CMT program increased trunk muscle strength and improved dynamic balance among pediatric male athletes.

Level of evidence

Level II

Dynamic Knee Valgus in Single-Leg Movement Tasks. Potentially Modifiable Factors and Exercise Training Options. A Literature Review

Dynamic knee valgus (DKV) as an incorrect movement pattern is recognized as a risk factor for lower limb injuries. Therefore, it is important to find the reasons behind this movement to select effective preventive procedures. There is a limited number of publications focusing on specific tasks, separating the double-leg from the single-leg tasks. Test patterns commonly used for DKV assessment, such as single-leg squat (SLS) or single leg landings (SLL), may show different results. The current review presents the modifiable factors of knee valgus in squat and landing single-leg tests in healthy people, as well as exercise training options. The authors used the available literature from PubMed, Scopus, PEDro and clinicaltrials.gov databases, and reviewed physiotherapy journals and books. For the purpose of the review, studies were searched for using 2D or 3D motion analysis methods only in the SLL and SLS tasks among healthy active people. Strengthening and activating gluteal muscles, improving trunk lateral flexion strength, increasing ROM dorsiflexion ankle and midfoot mobility should be taken into account when planning training programs aimed at reducing DKV occurring in SLS. In addition, knee valgus during SLL may occur due to decreased hip abductors, extensors, external rotators strength and higher midfoot mobility. Evidence from several studies supports the addition of biofeedback training exercises to reduce the angles of DKV.