Ankle-dorsiflexion range of motion and landing biomechanics

Contribution of ankle motion pattern during landing to reduce the knee-related injury risk

BACKGROUND

Single-leg landing (SL) is an essential technique in sports such as basketball, soccer, and volleyball, which is often associated with a high risk of knee-related injury. The ankle motion pattern plays a crucial role in absorbing the load shocks during SL, but the effect on the knee joint is not yet clear. This work aims to explore the effects of different ankle plantarflexion angles during SL on the risk of knee-related injury.

METHODS

Thirty healthy male subjects were recruited to perform SL biomechanics tests, and one standard subject was selected to develop the finite element model of foot-ankle-knee integration. The joint impact force was used to evaluate the impact loads on the knee at various landing angles. The internal load forces (musculoskeletal modeling) and stress (finite element analysis) around the knee joint were simulated and calculated to evaluate the risk of knee-related injury during SL. To more realistically revert and simulate the anterior cruciate ligament (ACL) injury mechanics, we developed a knee musculoskeletal model that reverts the ACL ligament to a nonlinear short-term viscoelastic mechanical mechanism (strain rate-dependent) generated by the dense connective tissue as a function of strain.

RESULTS

As the ankle plantarflexion angle increased during landing, both the peak knee vertical impact force (p = 0.001) and ACL force (p = 0.001) decreased significantly. The maximum von Mises stress of ACL, meniscus, and femoral cartilage decreased as the ankle plantarflexion angle increased. The overall range of variation in ACL stress was small and was mainly distributed in the femoral and tibial attachment regions, as well as in the mid-lateral region.

CONCLUSION

The current findings revealed that the use of larger ankle plantarflexion angles during landing may be an effective solution to reduce knee impact load and the risk of rupture of the medial femoral attachment area in the ACL. The findings of this study have the potential to offer novel perspectives in the optimized application of landing strategies, thus giving crucial theoretical backing for decreasing the risk of knee-related injury.

Prediction of ACL-tear by lower limbs muscle strength and flexibility: a prospective cohort study in 95 female soccer players

The aims of the study were to build models using logistic regression analysis of flexibility and strength tests to prospectively predict risk factors for anterior cruciate ligament tear (ACL-tear) in female soccer (FS) players, and to determine training cut-off for risk factors of the predictive model built. A prospective cohort study of 95 female players (aged 14-33 years) was conducted. Age, anthropometric data, soccer history, lower limb range of motion (ROM) and hip maximal isometric strength (MIS) were measured. At the prospective follow-up after 12 months, 7.4% of the players had developed an ACL-tear. The model showed a significant relationship (χ2(93) = 30.531, p < 0.001) between the ACL-tear and the predictor variables (leg length, HAD-NH [hip adduction] MIS, asymmetric ROM [ankle dorsiflexion with knee extended (AD-KE) and with knee flexed (AD-KF), and HE (hip extension)], hip ROM [HIR (internal rotation) and HAB (abduction)]). The Akaike Information Criteria (AIC) and Bayesian Information Criteria (BIC) for model fit were 30.24 and 51.79, respectively. The value R2 showed good model fit, 76.5% for Nagelkerke´s R2, 71.4% for McFadden´s R2 and 67.5% for Tjur´s R2. For the screening test, cut-off for leg length of ≥0.40 m, for HIR ROM of ≤44º and for asymmetry of HE ROM of ≥5° were set, which have an acceptable (AUC ≥ 0.755) discriminatory ability for the development of ACL-tear.

Strength and clinical test combinations enhance predictions of sagittal and frontal plane biomechanics in single-leg landing

OBJECTIVES

To determine whether clinical screening tests can predict lower limb joint kinematics and kinetics outcomes eliciting anterior cruciate ligament (ACL) injury risk in single-leg landings.

DESIGN

Cross-sectional study.

SETTING

Laboratory research.

PARTICIPANTS

Twenty-six professional male futsal athletes.

MAIN OUTCOME MEASURES

Participants completed the Modified Star Excursion Balance Test (mSEBT), Lateral Step Down (LSD), Lunge, Hop tests, and isometric strength tests for clinical screening of lower extremity injury risk and performed single-leg landings to assess lower extremity 3D kinematics and kinetics outcomes.

RESULTS

mSEBT, LSD, and isometric strength were the more important tests when constructing the prediction models. The predictive power of clinical tests for screening injury risk significantly increases when combined with strength measurements (p = 0.005, f2 = 0.595). We discerned 11 biomechanical predictions, six explicitly related to the sagittal plane's biomechanics. Some predictions were leg-dependent, with muscle strength tests predominantly predicting biomechanical outcomes of the preferred leg.

CONCLUSION

Combining clinical screening tests with strength measures enhances ACL injury risk factors prediction during single-leg landings. Clustering at least two tests improves prediction accuracy, aiding injury prevention planning and decision-making.

Can tests of physical fitness predict traumatic knee injury in youth female athletes? A prospective cohort study

OBJECTIVES

To compile a battery of test including various aspects of physical fitness that could be used on the field and to assess whether any of these tests are associated with future traumatic knee injuries in youth female team sports athletes.

DESIGN

Prospective cohort.

SETTING

Sport setting.

PARTICIPANTS

Female athletes (n = 117, age 15-19 years), from Swedish sport high schools, active in soccer, handball, or floorball.

MAIN OUTCOME MEASURES

Differences in pre-injury tests values of 11 physical fitness tests in injured versus non-injured athletes, assessed as number of traumatic knee injuries over one season.

RESULTS

28 athletes sustained 34 traumatic knee injuries. Athletes who sustained an injury had a shorter distance on the Yo-Yo IR1 test at baseline than those without an injury (mean difference -193 m, CI -293- -65 m). None of the other tests, assessed for muscular strength, endurance, power, flexibility and dynamic knee valgus, differed between injured and non-injured athletes.

CONCLUSIONS

Youth female athletes with lower intermittent endurance capacity, assessed with the Yo-Yo IR1, seemed to be at greater risk of traumatic knee injury. Neither hop performance, flexibility, dynamic knee valgus nor isolated strength tests at baseline could distinguish between injured and non-injured youth female athletes at follow-up.

Can Symmetry of Single-Leg Vertical Jump Height Represent Normal Lower Limb Biomechanics of Athletes After Anterior Cruciate Ligament Reconstruction?

BACKGROUND

After anterior cruciate ligament reconstruction (ACLR), single-leg horizontal hop distance limb symmetry index (LSI) >90% is recommended as a cutoff point for safe return to sport (RTS). However, athletes after ACLR have abnormal lower limb biomechanics despite an adequate single-leg hop distance LSI, implying that athletes are at high risk of reinjury. Symmetry of single-leg vertical jump height appears to be more difficult to achieve and can be a better representation of knee function than single-leg horizontal hop distance.

HYPOTHESIS

Athletes after ACLR with single-leg jump height LSI >90% had similar biomechanical characteristics to healthy athletes.

STUDY DESIGN

Controlled laboratory study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 46 athletes after ACLR were divided into low jump height (LJH, jump height LSI <90%, n = 23) and high jump height (HJH, jump height LSI >90%, n = 23) groups according to symmetry of single-leg vertical jump height, while 24 healthy athletes acted as a control (CONT) group. One-way analysis of variance was used to compare the kinematic and kinetic characteristics of the LJH, HJH, and CONT groups during single-leg vertical jump.

RESULTS

Both the LJH and HJH groups demonstrated greater limb asymmetry (lower LSI) during landing compared with the CONT group in knee extension moment (P < 0.05), peak knee flexion angle (P < 0.05), and knee power (P < 0.05).

CONCLUSION

Symmetry in single-leg vertical jump height does not represent normal lower limb biomechanics in athletes after ACLR.

CLINICAL RELEVANCE

Symmetrical jump height may not signify ideal biomechanical or RTS readiness, but single-leg vertical jump test can be used as a supplement to horizontal hop test or other functional tests to reduce the likelihood of false-negative results in the absence of detailed biomechanical evaluation.

Relationship between ankle dorsiflexion range of motion and sprinting and jumping ability in young athletes

OBJECTIVES

To investigate the relationship between predicted risk of injury based on the dichotomous classification of the weight-bearing lunge (WBL) test scores and variables related to jumping and sprinting ability in young athletes. Furthermore, to compare the impact of the classical dichotomous classification versus a more specific quartile subdivision of the WBL test scores on the explored variables.

DESIGN

Cross-sectional study.

PARTICIPANTS

125 healthy athletes (mean age 10.38 (SD = 2.28) years) were recruited.

MAIN OUTCOME MEASURES

Ankle dorsiflexion was evaluated with the WBL test, jumping distance with the standing long jump (SLJ) test, and maximal running speed with the 14-m and 28-m sprint test.

RESULTS

Athletes with WBL test scores lower than 10 cm exhibited significantly poorer results for the SLJ test as well as lower 14-m and 28-m sprint times than those with WBL test scores higher than 10 cm (p < 0.05). Likewise, when WBL test scores were subdivided by quartiles, a positive trend between range of motion and improved performance was shown.

CONCLUSIONS

Reduced ankle dorsiflexion mobility may affect sprinting and jumping ability in young athletes. In addition, a more detailed classification of ankle restriction by quartiles is proposed in this study in order to prevent injury and enhance athletic performance.

Effects of technological running shoes versus barefoot running on the intrinsic foot muscles, ankle mobility, and dynamic control: a novel cross-sectional research

BACKGROUND

Technological running shoes have become increasingly popular, leading to improvements in performance. However, their long-term effects on foot musculature and joint mobility have not been thoroughly studied.

OBJECTIVE

To compare the activation of the intrinsic foot muscles between runners wearing technological footwear and barefoot runners. Secondary objectives included assessing ankle dorsiflexion (DF) range of motion (ROM) and dynamic postural control in both groups.

METHODS

A cross-sectional study was conducted involving 22 technological footwear runners and 22 barefoot runners. Ultrasonography was used to measure the thickness of the plantar fascia (PF) and the quadratus plantae (QP), abductor digiti minimus (ADM), abductor hallucis (AH), and flexor hallucis longus (FHL) muscles. Ankle mobility and dynamic postural control were also recorded.

RESULTS

Ultrasonography measurements showed statistically significant differences for PF thickness (mean difference [MD]: -0.10 cm; 95% CI: -0.13, -0.05 cm), QP cross-sectional area (CSA) (MD: -0.45 cm2; 95% CI: -0.77, -0.12 cm2), ADM CSA (MD: -0.49 cm2; 95% CI: -0.70, -0.17 cm2), and FHL thickness (MD: 0.82 cm; 95% CI: 0.53, 1.09 cm), with all measurements being lower in the group wearing technological footwear compared to the barefoot runners. Ankle DF ROM was also significantly greater for the barefoot runners (MD: -5.1°; 95% CI: -8.6, -1.7°).

CONCLUSIONS

These findings suggest potential implications for the foot musculature and ankle mobility in runners using technological footwear.

Effects of triceps surae exercise-induced delayed onset muscle soreness on control of body stability in different postures

This research aimed to determine whether triceps surae delayed onset muscle soreness (DOMS) affects stability while performing different postural control tasks requiring upright and landing stabilization. Twenty-four participants who self-reported as healthy were recruited. Pre and 48 h after a protocol to induce DOMS in the triceps surae, participants were evaluated for DOMS perception, pressure pain threshold, and postural control (assessed by the center of pressure, CoP) during different standing and landing stabilization tasks. We found higher DOMS perception and lower pressure pain threshold 48 h after the exercise. Mediolateral CoP displacement was more sensitive to DOMS across different postural tasks, but no effects were found for bilateral standing. The landing time to stabilization elicited high individual variability in the presence of DOMS. Effects of DOMS in the performance of less challenging tasks, such as bipedal standing, were not found. We conclude that DOMS in the triceps surae impairs mediolateral postural control during challenging tasks such as unilateral standing and body forward lean. It highlights the need for caution and individualized approaches when incorporating movements requiring frontal plane control in training and rehabilitation sessions under the presence of DOMS.

Better outcomes using suture button compared to screw fixation in talofibular syndesmotic injuries of the ankle: a level I evidence-based meta-analysis

INTRODUCTION

The present meta-analysis evaluated current level I clinical trials which compared the use of a suture button (SB) versus syndesmotic screw (SS) fixation techniques for syndesmosis injuries of the ankle. The outcomes of interest were to compare patient-reported outcome measures (PROMs) and complications. It was hypothesised that SB might achieve better PROMs along with a lower rate of complications.

METHODS

This study was conducted according to the 2020 PRISMA statement. In August 2023, PubMed, Web of Science, Google Scholar, and Embase were accessed. All the randomised controlled trials (RCTs) which compared SB versus SS fixation for syndesmosis injuries of the ankle were accessed. Data concerning the American Orthopaedic Foot & Ankle Society (AOFAS), and Olerud-Molander score (OMS) were collected at baseline and at last follow-up. Data on implant failure, implant removal, and joint malreduction were also retrieved.

RESULTS

Data from seven RCTs (490 patients) were collected. 33% (161 of 490) were women. The mean length of the follow-up was 30.8 ± 27.4 months. The mean age of the patients was 41.1 ± 4.1 years. Between the two groups (SB and SS), comparability was found in the mean age, and men:women ratio. The SS group evidenced lower OMS (P = 0.0006) and lower AOFAS (P = 0.03). The SS group evidenced a greater rate of implant failure (P = 0.0003), implant removal (P = 0.0005), and malreduction (P = 0.04).

CONCLUSION

Suture button fixation might perform better than the syndesmotic screw fixation in syndesmotic injuries of the ankle.

Effect of Sex and Lateral Ankle Sprain History on Dorsiflexion Range Of Motion Asymmetry During the Weight Bearing Lunge Test

Background

Reduced dorsiflexion range of motion (DFROM) which is commonly seen following lateral ankle sprain (LAS) has the potential to influence lower extremity biomechanics which have been linked to increased injury risk in the female athlete. Current research on the effect of sex and LAS history on DFROM is limited.

Hypothesis/Purpose

This study had three aims 1) to determine the effect of sex, leg dominance and LAS history on DFROM, 2) to determine the effect of sex and LAS history on magnitude of DFROM symmetry and 3) to examine the association of sex on direction (whether dominant or non-dominant limb had the higher DFROM) of symmetry.

Study Design

Cross-Sectional Study.

Methods

DFROM was measured bilaterally in 105 recreational athletes all participating in multidirectional sports using the tape measurement method during the weight bearing lunge test (WBLT). A mean of three measurements was used for analysis. A 3-way mixed ANOVA was carried out to determine the interaction between sex, LAS history and leg dominance on DFROM and a 2-way ANOVA for the effect of sex and LAS history on asymmetry. A chi-square test was used to determine the association of sex and direction of asymmetry.

Results

The results indicate no significant effect of sex, LAS history, and leg dominance on DFROM (p=0.65). Main effects were significant for sex and LAS on DFROM. The mean asymmetry for all participants was reported as 12.25±14.76cm. No significant effect of sex and LAS history on magnitude of asymmetry was reported. There was a significant association of sex and direction of asymmetry (χ2(1) = 11.26, p = 0.00). Sixty-five-point two percent of males were shown to have higher DFROM of their non-dominant limb compared to 75% of females who were higher in their dominant limb.

Conclusion

Findings from this study suggest that DFROM is affected by sex and LAS history. While females have increased DFROM compared to males, those with LAS history are more likely to have a decreased DFROM on the involved side. The results also indicate that interlimb asymmetries in DFROM are present in athletes, therefore practitioners should exercise caution when using bilateral comparisons in injury and return to play assessments.

Level of Evidence

2b.

New Insights Optimize Landing Strategies to Reduce Lower Limb Injury Risk

Single-leg landing (SL) is often associated with a high injury risk, especially anterior cruciate ligament (ACL) injuries and lateral ankle sprain. This work investigates the relationship between ankle motion patterns (ankle initial contact angle [AICA] and ankle range of motion [AROM]) and the lower limb injury risk during SL, and proposes an optimized landing strategy that can reduce the injury risk. To more realistically revert and simulate the ACL injury mechanics, we developed a knee musculoskeletal model that reverts the ACL ligament to a nonlinear short-term viscoelastic mechanical mechanism (strain rate-dependent) generated by the dense connective tissue as a function of strain. Sixty healthy male subjects were recruited to collect biomechanics data during SL. The correlation analysis was conducted to explore the relationship between AICA, AROM, and peak vertical ground reaction force (PVGRF), joint total energy dissipation (TED), peak ankle knee hip sagittal moment, peak ankle inversion angle (PAIA), and peak ACL force (PAF). AICA exhibits a negative correlation with PVGRF (r = -0.591) and PAF (r = -0.554), and a positive correlation with TED (r = 0.490) and PAIA (r = 0.502). AROM exhibits a positive correlation with TED (r = 0.687) and PAIA (r = 0.600). The results suggested that the appropriate increases in AICA (30° to 40°) and AROM (50° to 70°) may reduce the lower limb injury risk. This study has the potential to offer novel perspectives on the optimized application of landing strategies, thus giving the crucial theoretical basis for decreasing injury risk.

Referential values for lower limb flexibility in healthy children and adolescents in Japan: A five-year cross-sectional study

BACKGROUND

Lower limb flexibility (LLF) is an essential motor function. However, assessing LLF during adolescence is difficult because of the influence of marked physical changes. We, therefore, assessed LLF and investigated the relationship between LLF and sex and age in healthy children and adolescents.

METHODS

We conducted a five-year cross-sectional study with students aged 8-14 years at a single school in Japan. We evaluated the heel-buttock distance (HBD), straight leg raising angle (SLRA), and dorsiflexion angle of the ankle joint (DFA) at the beginning of each year. We conducted a comparative analysis on the performance of the HBD, SLRA, and DFA techniques, stratified by both sex and age. The statistical significance of observed differences was assessed through the application of Mann-Whitney U and Kruskal-Wallis tests. Furthermore, we analyzed the effects of sex, age, height, and weight on LLF using a multivariable linear regression model.

RESULTS

Of the 4221 initial study participants, 3370 were analyzed. Mean HBD, SLRA, and DFA values were 1.6 cm, 77.0°, and 15.7°, respectively. Girls showed significantly higher HBD and lower SLRA and DFA values than boys and 14-year-olds (p < 0.01). Median HBD value for girls was 0 cm, whereas for boys, it exceeded 0 cm after age 13. The median SLRA value for girls was 80-85°, while for boys, it was 70-75°. The median DFA value for girls was 15-19°, and for boys, it was 12-15°. A multivariable linear regression model indicated that boys had significantly greater tightness than girls (p < 0.01).

CONCLUSIONS

The reference values of HBD, SLRA, and DFA differed according to age and sex. Furthermore, we showed that sex differences were significantly associated with LLF. Data in this study provide the reference value for assessing LLF in children and adolescents.

Injury prevention in Brazilian women's football: Perceptions of physiotherapists and practices within elite clubs

OBJECTIVES

To describe the perceptions of physiotherapists and the injury prevention practices implemented within elite women's football clubs in Brazil.

DESIGN

Cross-sectional study.

SETTING

Online survey.

PARTICIPANTS

Head physiotherapists from 32 Brazilian elite clubs.

MAIN OUTCOME MEASURES

Structured questionnaire.

RESULTS

Physiotherapists identified ACL rupture as the primary target for prevention. The top-five perceived injury risk factors included 'early return to sport after injury', 'workload too high', 'previous injury', 'poor sleep/rest', and 'muscle strength/power deficit'. 'Adoption of return to sport criteria' was almost unanimously recognized as a very important preventive strategy. 'Poor infrastructure' was elected as the main barrier to implementing prevention programs. From a practical standpoint, at least two-third of clubs implemented multi-component exercise interventions for injury prevention. These interventions typically encompassed flexibility/mobility, balance/proprioception, lumbo-pelvic stability, and agility exercises, alongside exposure to sprinting. Strength training routines typically included traditional, functional, and eccentric exercises. Most teams also employed other prevention strategies, including adoption of return to sport criteria, internal workload monitoring, post-exercise recovery modalities, preseason risk factor screening, and application of rigid strapping tapes.

CONCLUSIONS

This study provided unprecedented insights into the physiotherapists' perceptions and injury prevention practices implemented within elite women's football clubs.

The association of range of motion, lower limb strength, and load during jump landings in professional ballet dancers

This study aimed to investigate the associations between peak plantarflexion ankle joint moments and vertical ground reaction forces (vGRF) during jump landings, and static ankle dorsiflexion range of motion (ROM), three-dimensional ankle excursions, and lower extremity strength in professional ballet dancers. Twenty-seven professional ballet dancers volunteered to participate (men = 14, women = 13). Participants attended one data collection session to measure dorsiflexion ROM and isometric lower extremity strength. Two further sessions were used to establish ankle mechanics and vGRFs during countermovement jump landings in seven foot positions, via a seven-camera motion capture system and piezoelectric force platform. Two linear mixed-effects models were used to investigate associations between the target variables and strength, dorsiflexion ROM, and ankle excursions. Dancer identification, sex, and foot position were entered as random effects. Model fit, when considered independent of random effects, was generally poor with the predictor variables explaining little of the variance of peak plantarflexion ankle joint moments (R2 = 0.02) or vGRF (R2 = 0.01). Model fit improved when random effects were considered (R2 = 0.65 & 0.34). Frontal plane ankle excursion was the only predictor variable with a significant negative association with peak plantarflexion ankle joint moments (p = .016), although coefficient estimates were small. Strength, static ankle dorsiflexion ROM, and three-dimensional ankle excursions are poor predictors of load experienced at a joint and system level in professional ballet dancers. Differences between individuals, sex, and foot position may be better indicators of the load experienced during jump landings.

Exploring biomechanical variations in ankle joint injuries among Latin dancers with different stance patterns: utilizing OpenSim musculoskeletal models

Background: Dancers represent the primary demographic affected by ankle joint injuries. In certain movements, some Latin dancers prefer landing on the Forefoot (FT), while others prefer landing on the Entire foot (ET). Different stance patterns can have varying impacts on dancers' risk of ankle joint injuries. The purpose of this study is to investigate the differences in lower limb biomechanics between Forefoot (FT) dancers and Entire foot (ET) dancers. Method: A group of 21 FT dancers (mean age 23.50 (S.D. 1.12) years) was compared to a group of 21 ET dancers (mean age 23.33 (S.D. 0.94) years), performing the kicking movements of the Jive in response to the corresponding music. We import data collected from Vicon and force plates into OpenSim to establish musculoskeletal models for computing kinematics, dynamics, muscle forces, and muscle co-activation. Result: In the sagittal plane: ankle angle (0%-100%, p < 0.001), In the coronal plane: ankle angle (0%-9.83%, p = 0.001) (44.34%-79.52%, p = 0.003), (88.56%-100%, p = 0.037), ankle velocity (3.73%-11.65%, p = 0.017) (94.72-100%, p = 0.031); SPM analysis revealed that FT dancers exhibited significantly smaller muscle force than ET dancers around the ankle joint during the stance phase. Furthermore, FT dancers displayed reduced co-activation compared to ET dancers around the ankle joint during the descending phase, while demonstrating higher co-activation around the knee joint than ET dancers. Conclusion: This study biomechanically demonstrates that in various stance patterns within Latin dance, a reduction in lower limb stance area leads to weakened muscle strength and reduced co-activation around the ankle joint, and results in increased ankle inversion angles and velocities, thereby heightening the risk of ankle sprains. Nevertheless, the increased co-activation around the knee joint in FT dancers may be a compensatory response for reducing the lower limb stance area in order to maintain stability.

Effects of Nontraditional Division III Lacrosse Participation on Movement Pattern Quality and Dynamic Postural Control

Background/Purpose

No studies have observed the effects of a collegiate lacrosse season on movement pattern quality, dynamic postural control, or the accuracy of athletes' perceived movement pattern quality. The purpose was to examine the effects of a nontraditional fall season on movement pattern quality, perceived movement pattern quality, and dynamic postural control in collegiate lacrosse athletes.

Design

Cross-sectional laboratory study.

Methods

Fifty men's (age=19.38±1.24 years, height=182.63±6.16 cm, mass=82.37±8.46 kg) and 22 women's (age=19.68±1.17 years, height=165.10±6.88 cm, mass=64.09±8.72 kg) lacrosse players were recruited. Outcome measures included individual Functional Movement Screen™ (FMS™) scores, self-reported perceived movement pattern quality scores, lower and upper extremity Y-Balance Test (YBT) measurements, and active dorsiflexion range of motion (ROM) before the start and again at the end of the fall lacrosse season. Pre- and post-season measurements were assessed using paired t-tests and chi-squared analyses.

Results

FMS™ composite scores did not significantly change from preseason to postseason for males (p=0.74) or females (p=0.07). Male perceived movement pattern quality was significantly higher than measured for 10 of 12 movements (p<0.05). Female perceived movement pattern quality was significantly higher than measured for four of 12 movements (p<0.05). Asymmetry frequency significantly increased in males in the hurdle step from two individuals to nine (χ 2 1=25.52, p<0.01), inline lunge from 10 to 20 (χ 2 1=12.50, p<0.01), and shoulder mobility from 4 to 21 (χ 2 1=78.53, p<0.01). Asymmetries in male athletes significantly decreased in the active straight leg raise from 26 to 8 (χ 2 1=25.96, p<0.01). YBT composite scores increased in males for the right leg (p=0.001) and left leg (p<0.03). Right dorsiflexion ROM (p<0.001) and left dorsiflexion ROM (p<0.001) significantly decreased in males from preseason to postseason. YBT scores for the right leg significantly increased in females from preseason to postseason (p=0.01). YBT scores for females for the right arm significantly increased from preseason to postseason (p=0.045).

Conclusions

A 5-week season may not change overall movement pattern quality of men's or women's lacrosse players, but some individual movement scores diminished. Athletes may overestimate self-reported movement pattern quality and are therefore unlikely to individually address movement deficits. Male dynamic postural control may change throughout a season, resulting in a potential increased risk of injury later in the season due to compensatory patterns or changes in mobility, proprioception, or balance.

Level of Evidence

3b.

Variables Associated With Knee Valgus in Male Professional Soccer Players During a Single-Leg Vertical Landing Task

Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was .43 during the landing phase (P = .04) and with peak hip internal rotation was -.68 (P < .001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r = .40, P = .05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test.

Effects of shoe collar height and limb dominance on landing knee biomechanics in female collegiate volleyball players

Volleyball-specific footwear with higher collar heights (a mid-cut shoe) are worn to restrict ankle motion. Reduced ankle dorsiflexion has been associated with increased frontal plane motion and injury risk at the knee. With the high frequency of unilateral landings in volleyball, the purpose of this study was to determine the effect of volleyball-specific shoes and limb dominance on knee landing mechanics in collegiate volleyball players. It was hypothesized that participants would exhibit smaller sagittal plane and greater frontal plane knee joint mechanics in mid-cut and dominant limb and that vertical and posterior directed ground reaction forces would be greater wearing mid-cut, yet similar between limbs. Seventeen female volleyball players performed unilateral landings on each limb in mid-cut and low-top volleyball shoes. For shoe main effects, smaller peak dorsiflexion angle and internal peak plantarflexion moment and greater peak medial ground reaction force were found in the mid-cut but with no impact on knee mechanics. For limb main effects, the internal peak knee abduction moment was greater in the dominant limb. Greater peak lateral ground reaction force was found in the interaction between the non-dominant limb and low-top. Further research is warranted to better understand shoe and limb impact in volleyball players.

Influence of a football match on landing biomechanics and jump performance in female football players

This study aimed to assess the acute effect of a competitive football match on jump performance and kinematic parameters during jump landing in semiprofessional female football players. Twenty-two semiprofessional players (20 ± 3 years) underwent a drop jump task for a posterior video analysis of the landing phase. These measurements were obtained at (1) baseline, (2) after, and (3) 48 h after a competitive football match. A one-way ANOVA with repeated measures was employed to detect differences over the time. There was a main effect of time for maximal knee flexion angle during drop landing (p = 0.001). In comparison with baseline, maximal knee flexion angle was reduced immediately post-match and was still reduced 48 h after the match (63.4 ± 8.6 vs 57.0 ± 11.7 vs 48.9 ± 19.1, p ≤ 0.038). There was also a main effect of time for drop jump height (p < 0.001). Drop jump height was reduced immediately post-match and remained low 48 h after the match in comparison with baseline (27.3 ± 3.6 vs 24.5 ± 2.8 ~ 25.5 ± 3.0 cm, p ≤ 0.002). There was a main effect of time on hip flexion angle during landing (p = 0.001), but the pairwise comparison revealed that this variable was not affected immediately post-match but was lower 48 h after the match than at baseline (50.1 ± 10.1 ~ 50.8 ± 13.2 vs 38.1 ± 17.8 °, p ≤ 0.005). A competitive football match worsened jump performance and several landing biomechanical parameters in female football players, which were still decreased in comparison with baseline even 48 h after the match.

Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria).

The effect of manual therapy on ankle dorsiflexion range of motion: A pilot crossover randomized trial

INTRODUCTION

Restricted ankle dorsiflexion is common after lower limb injury. The aim of this pilot study was to investigate the effect of passive ankle joint mobilization and calf muscle massage on ankle dorsiflexion range of motion in adults with residual restricted dorsiflexion. The secondary aim was to assess the methodology of the pilot study to inform a larger clinical trial.

METHOD

The study design was a randomized crossover trial with assessor blinding. Twenty-five healthy participants with a history of lower limb injury were included in the study. Ankle joint mobilization and calf muscle massage were applied for 5 min in a random order, one to two weeks apart. Ankle dorsiflexion was measured by using the weight-bearing lunge pre- and post-intervention (cm). Paired t-tests were used to analyze the effect of the manual therapy interventions on restricted ankles. A minimal detectable difference 95% (MMD95) was calculated. The pilot study was analyzed for suitability of inclusion criteria, blinding of assessors and the manual therapist, and the washout period.

RESULTS

A significant increase in dorsiflexion was demonstrated for ankle joint mobilization (change score = 0.51 ± 0.76, p = 0.003) and calf muscle soft tissue massage (change score = 0.91 ± 1.07, p < 0.001). There was no difference in change scores between manual therapy techniques (mobilization 0.51 ± 0.76, massage 0.91 ± 1.07, p = 0.12). Evaluation of the pilot study revealed limitations to be modified in future studies.

CONCLUSION

These preliminary data indicate ankle joint mobilization and calf muscle soft tissue massage had similar effects on increasing ankle dorsiflexion range of motion in ankles with residual dorsiflexion restriction.

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.

Lower Extremity Energy Dissipation and Generation During Jump Landing and Cutting in Patients With Chronic Ankle Instability

CONTEXT

Participants with chronic ankle instability (CAI) frequently display altered movement patterns during functional movements. However, it remains unclear how these altered joint kinematics during jump landing negatively affect ankle joint health in the CAI population. Calculating joint energetics may offer an important method to estimate the magnitude of lower extremity joint loading during functional movements in participants with CAI.

OBJECTIVE

To determine differences in energy dissipation and generation by the lower extremity during maximal jump landing and cutting among groups with CAI, copers, and controls.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Forty-four participants with CAI, 44 copers, and 44 controls.

MAIN OUTCOME MEASURES(S)

Kinematics and kinetics of the lower extremity and ground reaction force data were collected during a maximal jump-landing and cutting task. The product of angular velocity in the sagittal plane and joint moment data represented joint power. Energy dissipation and generation by the ankle, knee, and hip joints were calculated by integrating regions of the joint power curve.

RESULTS

Participants with CAI displayed reduced ankle energy dissipation (35.9% ± 10.1%) and generation (31.6% ± 12.8%; P < .01) compared with copers (dissipation = 43.6% ± 11.1%; generation = 40.4% ± 12.0%) and controls (dissipation = 41.3% ± 11.1%; generation = 39.6% ± 12.0%) during maximal jump landing and cutting. Participants with CAI also displayed greater energy dissipation at the knee (45.1% ± 9.1%) than copers (39.7% ± 9.5%) during the loading phase and greater energy generation at the hip than controls (36.6% ± 16.8% versus 28.3% ± 12.8%) during the cutting phase. However, copers displayed no differences in joint energetics compared with controls.

CONCLUSIONS

Participants with CAI displayed differences in both energy dissipation and generation by the lower extremity during maximal jump landing and cutting. However, copers did not show altered joint energetics, which may represent a coping mechanism to avoid further injuries.

A randomized controlled trial comparing conservative versus surgical treatment in patients with foot drop due to peroneal nerve entrapment: results of an internal feasibility pilot study

BACKGROUND

Based on the lack of literature to support any treatment strategy in patients with foot drop due to peroneal nerve entrapment, a prospective study randomizing patients between surgery and conservative treatment is warranted. Since studies comparing surgery to no surgery are often challenging, we first examined the feasibility of such a randomized controlled trial.

METHODS/DESIGN

An internal feasibility pilot study was conducted to assess several aspects of process, resource, management, and scientific feasibility. The main objective was the assessment of the recruitment rate. The criterion to embark on a full study was the recruitment of at least 14 patients in 6 participating centers within 6 months. Cross-over rate, blinding measures, training strategies, and trial assessments were evaluated. The trial was entirely funded by the KCE Trials public funding program of the Belgian Health Care Knowledge Centre (ID KCE19-1232).

RESULTS

The initial duration was prolonged due to the COVID-19 pandemic. Between April 2021 and October 2022, we included 19 patients of which 15 were randomized. Fourteen patients were treated as randomized. One drop-out occurred after randomization, prior to surgery. We did not document any cross-over or accidental unblinding. Training strategies were successful. Patients perceived the quality of life questionnaire as the least relevant assessment. Assessment of ankle dorsiflexion range of motion was prone to interobserver variability. All other trial assessments were adequate.

DISCUSSION

Recruitment of the anticipated 14 patients was feasible although slower than expected. The Short-Form Health Survey (SF-36) and assessment of ankle dorsiflexion range of motion will no longer be included in the full-scale FOOTDROP trial.

CONCLUSION

The FOOTDROP study is feasible.

TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT04695834 . Registered 4 January 2021.

Acute effects of foam rolling on ankle dorsiflexion and squat exercise patterns in extreme conditioning program practitioners: A randomized clinical trial

BACKGROUND/OBJECTIVES

Joint and muscle overloads commonly occur in extreme conditioning programs (ECP), which require great physical fitness for their practice. For its execution, good functional performance, mobility and adequate movement patterns are required. The fascial system plays a fundamental role in performance in ECP and one of the techniques used to improve joint mobility and movement pattern is the self-myofascial release using a foam roller (FR). Our objective of this study was to evaluate the effect of FR in ankle dorsiflexion (DF) range of motion (ROM), assessed with the Lunge Test, and also in the squat movement pattern, assessed using the Technique smartphone application, in ECP practitioners.

METHODS

The study was carried out with 18 ECP practitioners who practiced for over four months and had a mean age of 30.94 years. The participants were randomized and allocated into two groups: control and intervention. The FR was self-applied bilaterally in the sural triceps region for 90 seconds. Tests to assess DF ROM and squat movement pattern were applied before and immediately after using FR (intervention group) or after three-minute rest (control group).

RESULTS

The use of the FR promoted an immediate increase in ankle DF ROM during the Lunge Test and during the squat and a decrease in dynamic knee valgus during the squat.

CONCLUSION

The FR can be used as a tool for an acute increase in DF ROM and a decrease in dynamic knee valgus, having a positive impact in improving movement patterns.

Noninvasive magnetic resonance-guided focused ultrasound for tendon disruption: an in vivo Animal study

PURPOSE

Surgical resection of the tendon is an effective treatment for severe contracture. Magnetic Resonance-guided Focused Ultrasound (MRgFUS) is a non-invasive ultrasonic therapy which produces a focal increase in temperature, subsequent tissue ablation and disruption. We evaluated MRgFUS as a clinically translatable treatment modality to non-invasively disrupt in vivo porcine tendons.

MATERIAL AND METHODS

In vivo Achilles tendons (n = 28) from 15-20kg Yorkshire pigs (n = 16) were randomly assigned to 4 treatment groups of 600, 900, 1200 and 1500 J. Pretreatment range of motion (ROM) of the ankle joint was measured with the animal under general anesthesia. Following MRgFUS treatment, success of tendon rupture, ROM increase, temperature, thermal dosage, skin burn, and histology analyses were performed.

RESULTS

Rupture success was found to be 29%, 86%, 100% and 100% for treatment energies of 600, 900, 1200 and 1500 J respectfully. ROM difference at 90° flexion showed a statistically significant change in ROM between 900 J and 1200 J from 16° to 27°. There was no statistical significance between other groups, but there was an increase in ROM as more energy was delivered in the treatment. For each of the respective treatment groups, the maximal temperatures were 58.4 °C, 63.3 °C, 67.6 °C, and 69.9 °C. The average areas of thermal dose measured were 24.3mm2, 53.2mm2, 77.8mm2 and 91.6mm2. The average areas of skin necrosis were 5.4mm2, 21.8mm2, 37.2mm2, and 91.4mm2. Histologic analysis confirmed tissue ablation and structural collagen fiber disruption.

CONCLUSIONS

This study demonstrated that MRgFUS is able to disrupt porcine tendons in vivo without skin incisions.

Overhead squat assessment reflects treadmill running kinematics

PURPOSE

Overhead squat assessment (OHSA) is a pre-activity dynamic movement analysis tool used to define deviations from an ideal motion pattern which known as compensation. Compensatory movements may result from abnormality in myofascial activity, length-tension relationships, neuro-motor control strategies, osteokinematics and arthrokinematics. The aim of this study is to identify the association between selected biomechanical variables of the ankle, knee, hip, pelvis, torso during OHSA and 16 km/h treadmill running tasks.

METHODS

Thirteen national long distance male runners (17.3 ± 0.5 age (years); 5.89 ± 1.95 experience (years), 57.9 ± 3.7 body mass (kg); 175.4 ± 5.7 height (cm)) participated in this 2controlled laboratory study. Three-dimensional kinematics were collected at 250 Hz using a 9-camera Qualisys motion analysis system (Qualisys AB, Goteborg, Sweden) while participants performed 16 km/h treadmill running and OHSA tasks.

RESULTS

Correlation coefficients demonstrated that OHSA pelvic anterior tilt angle was in a positive association with foot strike (FS), mid-stance (MS), and toe-off (TO) pelvic anterior tilt angles and MS tibial internal rotation on talus, MS ankle pronation, MS hip internal rotation. OHSA pelvic anterior tilt angle was in a negative association with TO hip extension. OHSA maximal hip adduction was positively correlated with MS and stance maximal knee adduction. FS, MS, stance maximal angular dorsiflexion values were positively correlated with OHSA dorsiflexion. Increased OHSA dorsiflexion angle was negatively associated with TO plantar flexion. OHSA pronation was positively associated with MS and stance pronation. MS hip internal rotation, MS hip adduction angles were increased, and MS ankle dorsiflexion was significantly decreased with the increase of trunk forward lean relative to tibia during OHSA.

CONCLUSIONS

OHSA was associated with some important and dysfunction-related hip, knee and ankle kinematics. Running coaches, may use OHSA as an assessment tool before the corrective training plan to detect injury-related compensation patterns to reduce the risk of injury and improve running technique.

Intrinsic variables associated with low back pain and lumbar spine injury in fast bowlers in cricket: a systematic review

BACKGROUND

Lumbar spine injuries in fast bowlers account for the greatest missed playing time in cricket. A range of extrinsic and intrinsic variables are hypothesised to be associated with low back pain and lumbar spine injury in fast bowlers, and an improved understanding of intrinsic variables is necessary as these may alter load tolerance and injury risk associated with fast bowling. This review critically evaluated studies reporting intrinsic variables associated with low back pain and lumbar spine injury in fast bowlers and identified areas for future investigation.

METHODS

OVID Medline, EMBASE, SPORTDiscus, CINAHL, Web of Science and SCOPUS databases were last searched on 3 June 2022 to identify studies investigating intrinsic variables associated with low back pain and lumbar spine injury in cricket fast bowlers. Terms relevant to cricket fast bowling, and intrinsic variables associated with lumbar spine injury and low back pain in fast bowlers were searched. 1,503 abstracts were screened, and 118 full-text articles were appraised to determine whether they met inclusion criteria. Two authors independently screened search results and assessed risk of bias using a modified version of the Quality in Prognostic Studies tool.

RESULTS

Twenty-five studies met the inclusion criteria. Overall, no included studies demonstrated a low risk of bias, two studies were identified as moderate risk, and twenty-three studies were identified as high risk. Conflicting results were reported amongst studies investigating associations of fast bowling kinematics and kinetics, trunk and lumbar anatomical features, anthropometric traits, age, and neuromuscular characteristics with low back pain and lumbar spine injury.

CONCLUSION

Inconsistencies in results may be related to differences in study design, injury definitions, participant characteristics, measurement parameters, and statistical analyses. Low back pain and lumbar spine injury occurrence in fast bowlers remain high, and this may be due to an absence of low bias studies that have informed recommendations for their prevention. Future research should employ clearly defined injury outcomes, analyse continuous datasets, utilise models that better represent lumbar kinematics and kinetics during fast bowling, and better quantify previous injury, lumbar anatomical features and lumbar maturation.

TRIAL REGISTRATION

Open Science Framework https://doi.org/10.17605/OSF.IO/ERKZ2 .

Comparative analysis of ankle injury kinematics and dynamics in basketball players: forefoot landing vs. rearfoot landing modes

OBJECTIVE

To compare the differences in ankle joint parameters of basketball athletes between the forefoot and rearfoot landing and to investigate the injury mechanism of ankle joints in different landing modes.

METHODS

Twenty level II male basketball athletes were selected as subjects in this study. The landing movements of these athletes were assigned into a forefoot landing mode and a rearfoot landing mode. The former includes movements such as running emergency stop, two-leg jump and forefoot landing, while the latter includes actions such as running emergency stop, two-leg jump and rearfoot landing. The motion capture system and three-dimensional force measuring table were used for collecting the kinematic and dynamic data of the subjects.

RESULTS

The initial landing angles, including ankle dorsiflexion and medial ankle rotation of the forefoot were larger than those of the rearfoot (all P<0.05). Compared to those in the rearfoot landing mode, the forefoot landing exhibited a greater peak angle of ankle plantar flexion and ankle varus, as well as a smaller peak angle of ankle dorsiflexion and ankle internal rotation (all P<0.05). In comparison to the rearfoot landing mode, the forefoot landing showed a larger range of ankle varus and valgus, as well as a smaller range of ankle dorsiflexion and plantar flexion (all P<0.05). The ankle plantar flexion torque of forefoot landing was higher than that of rearfoot landing, while the peak ankle dorsiflexion torque of forefoot landing was smaller than that of rearfoot landing (all P<0.05). Compared to those in the rearfoot landing mode, the outward peak ground reaction force was smaller and the forward peak ground reaction was larger in forefoot landing mode (all P<0.05). No obvious differences were observed in other indicators between two landing modes.

CONCLUSIONS

There are kinematic and dynamic differences between the forefoot and rearfoot landing. Forefoot landing may increase the risk of ankle injury during landing.

Influence of quality of reduction using radiological criteria on kinematics and kinetics in ankle fractures with unstable syndesmotic injury

BACKGROUND

In ankle fractures with syndesmotic injury, the anatomic reduction of the ankle mortise is crucial for preventing osteoarthritis. Yet, no studies have analysed the effect of surgical reduction after unstable ankle fractures on patients' active functional outcome.

METHODS

The Intraoperative 3D imaging data of patients surgically treated between 2012 and 2019 for ankle fracture with concomitant syndesmotic injury were reviewed. 58 patients were allocated to two groups depending on whether the criteria for radiologically optimal reduction were met (39 patients) or not (19 patients). Criteria for optimal reduction were composed of objectively measured and subjectively rated data. After undertaking the Olerud/Molander ankle score, a gait analysis and several active function tests using 3D motion capture were performed in order to evaluate kinetic and kinematic differences between both groups.

FINDINGS

Patients showed deficits of range of motion and balance parameters on the injured ankle, however, there were no significant differences between both groups.

INTERPRETATION

Although, the data did not show that radiological reduction criteria have a statistically significant effect on active functional outcome after a mean follow up time of 5.7 years, tendencies for a better outcome of patients that met the criteria could be seen. It also must be taken into consideration that results are limited by case number and allocation ratio, which made a sub-analysis of the separate reduction criteria unfeasible.

Effects of a neuromuscular training program on physical performance and asymmetries in female soccer

Introduction: Women's football require optimal neuromuscular system development for injury prevention and performance optimization. Standardized neuromuscular training programs have shown promising results in reducing injuries and functional asymmetries, but evidence on their impact on performance is limited. Methods: This research examined the effects of a 10-week neuromuscular training program on physical performance and asymmetries in female football players. Thirty-eight female players from two Spanish Second Division women's football teams participated in the study. The physical performance tests used were: ankle dorsiflexion, bilateral and unilateral horizontal jump, bilateral and unilateral vertical countermovement jump, 40 m sprint including partial times at 10, 20 and 30 m and the 505 test for change of direction evaluation. For 10 weeks, players in the experimental group performed three weekly 24-min neuromuscular training sessions. Participants in the control group completed their normal 24-min strength and conditioning program. Results: The main results were that maximal linear velocity and change of direction skills showed the most notable improvements [effect size (ES), 0.46 to 0.59] after implementation of the training program, ankle dorsiflexion and jumping skills, also improved although, to a lesser extent (ES, <0.35) while asymmetries between limbs were reduced. Maximal running speed improved in the intervention group (p < 0.001) with a mean ES -0.59. Discussion: We conclude that a 10-week neuromuscular training program can be a sufficient stimulus to improve football-specific performance variables in high-level female football players. Therefore, female players and coaches should be aware that weekly inclusion of strength, power and dynamic balance exercises following a neuromuscular paradigm is helpful for football-specific performance improvement.

Dorsiflexion shoes affect joint-level landing mechanics related to lower extremity injury risk in females

Athletic shoes that induce dorsiflexion in standing can improve jump height compared to traditional athletic shoes that induce plantarflexion, but it is unknown if dorsiflexion shoes (DF) also affect landing biomechanics associated with lower extremity injury risk. Thus, the purpose of this study was to investigate if DF adversely affect landing mechanics related to patellofemoral pain and anterior cruciate ligament injury risk compared to neutral (NT) and plantarflexion (PF) shoes. Sixteen females (21.65 ± 4.7 years, 63.69 ± 14.3 kg, 1.60 ± 0.05 m) performed three maximum vertical countermovement jumps in DF (-1.5°), NT (0°) and PF (8°) shoes as 3D kinetics and kinematics were recorded. One-way repeated-measures ANOVAs revealed peak vertical ground reaction force, knee abduction moment and total energy absorption were similar between conditions. At the knee, peak flexion and joint displacement were lower in DF and NT, while relative energy absorption was greater in PF (all p < .01). Conversely, relative ankle energy absorption was greater in DF and NT compared to PF (p < .01). Both DF and NT induce landing patterns that may increase strain on passive structures in the knee, emphasising the need for landing mechanics to be considered when testing footwear as gains in performance could come at the cost of injury risk.

Correlation of ankle dorsiflexion range of motion with lower-limb kinetic chain function and hop test performance in healthy male recreational athletes

Background

The study aims to identify the correlation of ankle dorsiflexion range-of-motion (ADROM) (with its related gastrocnemius and soleus extensibility) with lower-limb kinetic chain function and hop test performance in young healthy recreational athletes.

Methods

Twenty-one young male healthy recreational athletes were tested for ADROM, gastrocnemius and soleus extensibility, lower-limb kinetic chain function with the closed kinetic chain lower extremity stability test (CKCLEST) and hop test performance with the single-leg hop for distance test (SHDT) and side hop test (SHT).

Results

There was a positive significant (rho = 0.514, 95% CI [0.092-0.779], P < 0.01) correlation between the dominant lower-limb weight-bearing/closed-chain ADROM (that represented the soleus extensibility) and the CKCLEST. There were no significant correlations between the study performance-based tests and open-chain ADROM (P > 0.05).

Conclusion

The CKCLEST is positively and significantly correlated with SHT and weight-bearing ADROM with knee flexion (and its related soleus extensibility) which suggests comparability among them. Open-chain ADROM has a negligible and non-significant correlation with the readings of this study performance-based tests suggesting that it is probably not an essential construct of their execution. To the best of our knowledge, this study is the first to investigate these correlations.

Association of Proximal and Distal Factors With Lower Limb Kinematics During a Classical Ballet Jump

CONTEXT

Excessive dynamic lower limb misalignment may predispose ballet dancers to jump-related injuries. However, it is unknown whether proximal and distal factors influence this movement pattern. The aim of this study was to investigate whether hip abduction strength, foot alignment, and ankle dorsiflexion range of motion (ROM) are associated with peak angles of hip adduction and internal rotation and knee abduction during the preparation and landing phases of a classical ballet jump.

DESIGN

Cross-sectional study.

METHODS

Forty-one healthy amateur ballet dancers were included. Hip abduction strength was evaluated isometrically using a handheld dynamometer, foot alignment was determined by the shank-forefoot alignment, and weight-bearing ankle dorsiflexion ROM was measured by performing the lunge test. Peak hip and knee angles were analyzed 3-dimensionally during the preparation and landing phases of a single-leg jump. A Pearson correlation matrix was used to investigate the association of hip abduction strength, shank-forefoot alignment, and ankle dorsiflexion ROM with peak angles of hip adduction and internal rotation and knee abduction during the preparation and landing phases of the jump.

RESULTS

Greater hip abduction strength was associated with greater peak hip internal rotation angle (r = .43, P < .05), but not with peak hip adduction and knee abduction angles during the preparation phase of the jump. There were no associations of shank-forefoot alignment and ankle dorsiflexion ROM with peak hip and knee angles during the preparation (r = -.23 to .36, P > .05) and landing (r = -.20 to .24, P > .05) phases of the jump. There was no association of hip abduction strength with peak hip and knee angles during the landing phase of the jump (r = -.28 to .16, P > .05).

CONCLUSION

Hip abductors strengthening, correction of foot misalignments, and increasing ankle dorsiflexion ROM may not prevent excessive hip and knee movements during a classical ballet single-leg jump in amateur dancers.

Mechanical Linkage between Achilles Tendon and Plantar Fascia Accounts for Range of Motion of Human Ankle-Foot Complex

PURPOSE

The human ankle-foot complex possesses a passive range of motion (ROM) through changes in tibiocalcaneal ( θcal ) and foot arch ( θarch ) angles. Based on the anatomical linkage between the Achilles tendon (AT) and plantar fascia (PF), we hypothesized that AT and PF with different mechanical properties conjointly modulate the passive ROM of the human ankle-foot complex. We examined the association of AT and PF stiffness with passive ankle-foot ROM and further addressed differences between sexes.

METHODS

A series of sagittal magnetic resonance images of the foot and passive ankle plantar flexion torque were obtained for 20 men and 20 women with their ankle-foot passively rotated from 30° of plantar flexion to 20° of dorsiflexion. Based on the measured changes in AT and PF lengths, θcal , θarch , and passive torque, AT and PF stiffness were determined.

RESULTS

Upon passive ankle dorsiflexion, AT and PF were lengthened; their length changes were inversely correlated. Men showed a stiffer AT, more compliant PF, less calcaneal rotation, and greater foot arch deformation compared with women. Furthermore, we found inverse correlations between AT stiffness and ROM of θcal , and between PF stiffness and ROM of θarch in men and women.

CONCLUSIONS

Passive AT and PF extensibility counter each other. AT and PF stiffness and passive ROM of ankle-foot components were countered between sexes; however, associations between stiffness and passive ROM of the ankle-foot complex were consistent between sexes. Our findings support the notion that the balanced mechanical interaction between the AT and PF can account for the passive ROM of the human ankle-foot complex in vivo , and the differences between sexes.

Comparison and analysis of the biomechanics of the lower limbs of female tennis players of different levels in foot-up serve

Purpose: The purpose of this study was to examine biomechanical performance of the foot-up serve (FUS) in female tennis players at different skill levels. Methods: FUS analysis was completed in the biomechanical laboratory by 32 female college tennis players at three different levels. During FUS, 3D-biomechanical data from tennis players' lower limbs were collected. One-way ANOVA was used to examine differences in kinematic and kinetic data between groups Results: Range of motion (ROM) of bilateral lower-limb joints revealed significant differences in kinematics performance during both the preparation and landing cushion phases (p < 0.05). During preparation, Level 3 was significantly longer than Level 2 (P-a = 0.042, P-b = 0.001, and P-c = 0.006). During the flight phase, significant differences between levels 1 and 3 (P-a:0.002) and levels 1 and 2 (P-c:0.000) were discovered (P-a:0.002 and P-c:0.000). There were significant height differences between levels 1 and 2 as well as between levels 1 and 3. (P-a = 0.001, P-c = 0.000). During serve preparation (P-c = 0.001) and landing, GRF's peak was significantly higher than level 3. (P-c:0.007). Significant differences were found between groups in the LLS preparation stage, with level 3 significantly higher than levels 1 and 2. (P-a = 0.000, P-b = 0.001, and P-c = 0.000); during landing, level 2 LLS was significantly higher than levels 1 and 3. (P-a = 0.000, P-b = 0.000, and P-c = 0.035). Conclusion: The range of motion of joints and the stiffness of the lower limbs have a significant impact on a tennis player's FUS performance. A larger of joint mobility and lower-limb stiffness promote better performance during the FUS preparation stage.

Ankle dorsiflexion range of motion and landing postures during a soccer-specific task

INTRODUCTION

Ankle dorsiflexion range of motion (DF-ROM) has been shown to be associated with poor landing posture. However, previously used tasks have been controlled, and it is unclear whether clinical measurements of the ankle DF-ROM, are associated with landing positions during sport-specific task. This study sought to determine the relationship between ankle DF-ROM and landing positions.

METHODS

Thirty male soccer players participated in this study. The ankle DF-ROM was measured by the weight bearing lunge test in degrees using a cell phone app (TiltMeter). Landing patterns were assessed during a soccer-specific task using landing error scoring system items using Kinovea software. Simple correlations were used to evaluate the relationships between ankle DF-ROM and landing error scores.

RESULTS

Significant correlations were found between ankle DF-ROM and landing errors (r = -0.450, P = 0.006). A decreased ankle DF-ROM was associated with greater landing errors in a soccer specific situation.

CONCLUSION

These results suggest that ankle DF-ROM may serve a useful clinical measure for identifying poor landing posture in the real-world environment. Therefore, assessment of ankle DF-ROM could be included in the screening process, which could help identify the cause of the faulty motion.

Frontal plane projection angle predicts patellofemoral pain: Prospective study in male military cadets

BACKGROUND

Patellofemoral pain (PFP) is a major source of knee pain. Identifying who may develop PFP is of paramount importance.

PURPOSE

To assess whether Frontal plane projection angles (FPPA) and hand held dynamometry (HHD) strength measures can predict development of PFP.

STUDY DESIGN

Prospective evaluation of individuals undertaking a military training programme.

METHODS

Male military recruits were enrolled and prospectively followed up from enrolment to completion of 12-weeks training. Lower limb kinematics (FPPA, Q-angle, hip adduction angle, knee flexion, ankle dorsiflexion, and rearfoot eversion angle) measured during running, single leg squatting (SLS), and single leg landing (SLL) and isometric muscle strength of hip abductors and knee extensors.

RESULTS

Body mass, hip abductor muscle strength, Q-angle during SLS and SLL, FPPA during SLL all significantly different between the PFP and non-injured groups and predicted PFP, highest predictor variable was FPPA during SLL (Odds Ratio = 1.13, P = 0.01). A FPPA≥5.2° during SLL predicting PFP with a sensitivity of 70% and a specificity of 70%.

CONCLUSION

Participants who developed PFP had a number of physical factors significantly different than the non-injured group, most predictive was a larger FPPA during SLL, with angles greater than 5.2° associated with a 2.2x greater risk.

CLINICAL RELEVANCE

Assessing FPPA during SLL could be used to determine who was predisposed to PFP.

Effects of movement direction and limb dominance on ankle muscular force in sidestep cutting

Sidestep cutting is a critical movement in sports. However, biomechanical research on sidestep cutting has not hitherto reached a consensus. In order to investigate the effects of limb dominance and movement direction on ankle and subtalar joints during sidestep cutting, twelve physically active male participants were recruited in the present study. Trajectory and ground reaction force data were collected by the motion capture system and force platform. Kinematics, kinetics, and muscle forces information were obtained by running OpenSim. Two-way repeated measures ANOVA was performed with movement direction and limb dominance as independent variables. We found that movement direction had a significant effect on ankle dorsiflexion angle. In contrast, the factor of limb dominance had no effect on ankle and subtalar joints angles. For ankle joint moment, the plantarflexion moment was greater by performing a 45° sidestep cutting or using the dominant limb, while the subtalar joint moment was not affected by these two variables. In terms of muscle forces, the soleus of the dominant limb generated greater plantarflexion muscle force on the sagittal plane, while the non-dominant limb tended to contract more strongly (peroneus longus and peroneus brevis) on the frontal plane to stabilize the subtalar joint. Meanwhile, a smaller sidestep cutting angle made participants generate greater plantarflexion muscle forces (soleus and gastrocnemius). In conclusion, our findings indicated that participants should take limb dominance and movement direction into consideration for enhancing athletic performance and reducing the risk of injury during sidestep cutting.

The relationship between ankle dorsiflexion range of motion, frontal plane projection angle, and patellofemoral pain syndrome

BACKGROUND

Ankle range of motion abnormalities have been often linked with alteration in knee kinematics leading to the development of patellofemoral pain syndrome (PFPS). Literature exploring the relationship between ankle dorsiflexion range of motion (DF ROM) and knee kinematics during functional tasks is scanty. This study aims to assess the relation between ankle DF ROM and frontal plane projection angle (FPPA), one of the knee kinematic variables, in individuals with and without PFPS during a step-down test.

METHODS

This is a case-control study in which seventy PFPS patients and other 70 asymptomatic control subjects had their ankle DF ROM measured using an inclinometer with the knee flexed and extended. Their FPPA angles were measured using Kinovea software while doing the step-down test.

RESULTS

When the two groups were compared, ankle DF ROM measured with the knee flexed was higher in the control group (33.15 ± 4.96) than in the PFPS group (30.20 ± 6.93) (p = 0.03). In both the PFPS group and the control group, the correlation between FPPA and ankle DF ROM with the knee flexed was statistically insignificant (p = 0.075 and 0.323 respectively).

CONCLUSION

Decreased ankle DF ROM can be one of the contributing factors to the development of PFPS in the context of greater dynamic knee valgus.

Effects of different intermittent pneumatic compression stimuli on ankle dorsiflexion range of motion

Despite substantial evidence of the effectiveness of intermittent pneumatic compression (IPC) treatments for range of motion (ROM) improvement, little evidence is available regarding how different IPC stimuli affect ankle dorsiflexion (DF) ROM. This study aimed to investigate the effects of different IPC stimuli on the ankle DF ROM. Fourteen, university intermittent team sport male athletes (age: 21 ± 1 year, height: 1.74 ± 0.05 m, body mass: 70.9 ± 7.7 kg, body fat percentage: 14.2 ± 3.6%, body mass index: 23.5 ± 2.5 kg/m²; mean ± standard deviation) completed four experimental trials in a random order: 1) no compression with wearing IPC devices (SHAM), 2) the sequential compression at approximately 80 mmHg (SQUEE80), 3) the uniform compression at approximately 80 mmHg (BOOST80), and 4) the uniform compression at approximately 135 mmHg (BOOST135). For the experimental trials, the participants were initially at rest for 10 min and then assigned to either a 30-min SHAM, SQUEE80, BOOST80, or BOOST135. Participants rested for 20 min after IPC treatment. The Weight-Bearing Lunge Test (WBLT), popliteal artery blood flow, pressure-to-pain threshold (PPT), muscle hardness, heart rate variability, and perceived relaxation were measured before (Pre) and immediately after IPC treatment (Post-0) and 20 min after IPC treatment (Post-20), and the changes in all variables from Pre (Δ) were calculated. ΔWBLT performance, ΔPPT, and Δperceived relaxation in all IPC treatments were significantly higher than those in SHAM at Post-0 and Post-20 (p < 0.05). ΔPopliteal artery blood flow in BOOST80 and BOOST135 was significantly higher than that in SHAM and SQUEE80 at Post-0 (p < 0.05). ΔMuscle hardness and Δheart rate variability did not differ significantly between trials. In conclusion, IPC treatments, irrespective of applied pressure and mode of compression, increased ankle DF ROM. This resulted from decreased pain sensitivity (i.e., increased PPT). In addition, high inflation pressure and frequency did not provide additional benefits in increasing ankle DF ROM.

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.

The Results of Orthopaedic Medical Examinations in Adolescent Amateur Weightlifters

Few studies have reported injuries and physical characteristics in adolescent weightlifters. The purpose of this study was to report the results of orthopaedic medical examinations in adolescent amateur weightlifters that were performed cross-sectionally from 2012 to 2019. The orthopaedic medical examination included physical examinations, generalized joint laxity, muscle and joint tightness, static alignment, muscle volume of the lower extremities, and medial longitudinal arch of the foot (the height from the tip of the navicular tubercle to the ground surface). A questionnaire survey regarding pain in the spine and lower extremities was also performed. A total of 99 adolescent weightlifters were included (male/female, 71/28; mean age, 16.2 ± 0.2 years). A total of 9.1% had received orthopaedic treatments, with spine injuries being the most prevalent. Of those who had not received orthopaedic treatments, 31.1% had pain in the spine or lower extremities (for >4 weeks). There were no significant gender differences in the incidence of pain or positive findings of physical examinations. Female weightlifters had a more reduced dorsiflexion of the ankle joint than male weightlifters (p = 0.02). Male weightlifters had a lower flexibility of the quadriceps than female weightlifters. The results of orthopaedic medical examinations in this study may help clinicians and young weightlifters to prevent injuries in competitive weightlifting.

Comparing the Effects of Differential Learning, Self-Controlled Feedback, and External Focus of Attention Training on Biomechanical Risk Factors of Anterior Cruciate Ligament (ACL) in Athletes: A Randomized Controlled Trial

The current study aimed to compare the possible effects of differential learning strategy, self-controlled feedback, and external focus of attention on kinetic and kinematic risk factors of anterior cruciate ligament (ACL) injury in athletes. Forty-eight male athletes from three sports of handball, volleyball and basketball were selected for this study and were randomly divided into four groups: differential learning (n = 12), self-control feedback (n = 12), external focus (n = 12), and control (n = 12) group. All groups followed the intervention for eight weeks with three sessions per week. Data were analyzed by means of 4 × 2 repeated measures ANOVA followed by post hoc comparison (Bonferroni) at the significance level of p ≤ 0.05. A significant group × time interaction and the main effect of time was found for most kinetic and kinematic variables. The main effect of the group was significant only at the knee abduction angle. Differential learning and external focus of attention methods positively reduced the kinetic and kinematic variables that are considered risk factors for ACL injury. However, the effect sizes (Cohen's d) for the changes in most of the variables were larger for the differential learning group. Tailoring the boundary conditions that are based on the manipulations created in the exercise through variability and variety of movements associated with differential learning methods rather than repeating movements could reduce the risk of ACL injury.

Dorsiflexion and Hop Biomechanics Associate with Greater Talar Cartilage Deformation in Those with Chronic Ankle Instability

PURPOSE

This study aimed to identify associations between dorsiflexion range of motion (DFROM), functional hop test performance, and hopping biomechanics with the magnitude of talar cartilage deformation after a standardized hopping protocol in individuals with and without chronic ankle instability (CAI).

METHODS

Thirty CAI and 30 healthy individuals participated. Ankle DFROM was assessed using the weight-bearing lunge test. Four different functional hop tests were assessed. Three-dimensional kinematics and kinetics were sampled during a 60-cm single-leg hop. We calculated cartilage deformation after a dynamic loading protocol consisting of sixty 60-cm single-leg forward hops by assessing the change in average thickness for the overall, medial, and lateral talar cartilage. Linear regressions examined the associations between cartilage deformation magnitude and DFROM, functional hop tests, and hop biomechanical variables after accounting for body weight and time since the initial ankle sprain.

RESULTS

In CAI group, lesser static DFROM (ΔR2 = 0.22) and smaller peak ankle dorsiflexion angle (ΔR2 = 0.17) was associated with greater medial deformation. Greater peak vertical ground reaction force (vGRF) (ΔR2 = 0.26-0.28) was associated with greater medial and overall deformation. Greater vGRF loading rate (ΔR2 = 0.23-0.35) was associated with greater lateral and overall deformation. Greater side hop test times (ΔR2 = 0.31-0.36) and ankle plantarflexion at initial contact (ΔR2 = 0.23-0.38) were associated with greater medial, lateral, and overall deformation. In the control group, lesser side hop test times (ΔR2 = 0.14), greater crossover hop distances (ΔR2 = 0.14), and greater single-hop distances (ΔR2 = 0.21) were associated with greater overall deformation.

CONCLUSIONS

Our results indicate that lesser static DFROM, poorer functional hop test performance, and hop biomechanics associate with greater talar cartilage deformation after a dynamic loading protocol in those with CAI. These factors may represent targets for therapeutic interventions within this population to slow ankle posttraumatic osteoarthritis progression.

Comparison of landing kinematics and kinetics between experienced and novice volleyball players during block and spike jumps

BACKGROUND

The practice of volleyball requires many jumps. During landing, anterior cruciate ligament injuries may occur with high-risk lower limb kinematics and kinetics. Differences in landing strategies between experienced and novice volleyball players have not been fully explored. The purpose of the study was to compare lower limb kinematics and kinetics in experienced and novice volleyball players when performing volleyball specific jumps.

METHODS

A total of 30 healthy males, 15 experienced and 15 novice volleyball players, participated in the study. Participants performed block and spike jumps at a controlled jump height. Hip, knee and ankle joints angles at initial ground contact and ranges of motion in the sagittal plane, knee joint angles and moments in the frontal plane, vertical ground reaction force peak and loading rate were analyzed to investigate the expertise effect.

RESULTS

Experienced volleyball players landed with larger ankle dorsiflexion range of motion compared to novices. For the spike jump, experienced players landed with larger ankle plantarflexion angles at initial contact and larger ankle dorsiflexion ranges of motion, and for the block jump, they landed with larger knee flexion ranges of motion. Experienced players jumped significantly higher than novices. No difference was found in vertical ground reaction force peaks and loading rates.

CONCLUSIONS

Although the experienced group jumped higher than the novice group, no difference was found in ground reaction force parameters. These findings highlight that the experience of volleyball players acquired during regular trainings and competitions may play an important role in landing kinematics and kinetics to reduce the injury risk.

Influence of Ankle Injury on Subsequent Ankle, Knee, and Shoulder Injuries in Competitive Badminton Players Younger Than 13 Years

Background:

In recent years, there has been a trend in badminton toward more specialized training at an earlier age. Accompanying this trend is the increased frequency of injuries in young players. Ankle injury is the most common injury in pediatric sports; however, its influence on subsequent injuries is rarely considered.

Purposes:

To evaluate the incidence of ankle, knee, and shoulder injuries in youth badminton and to investigate the influence of ankle injuries on subsequent ankle, knee, and shoulder injuries.

Study Design:

Descriptive epidemiology study; Level of evidence, 3.

Methods:

A custom-designed questionnaire was used to survey Japanese players 7 to 12 years of age who attended national elementary school–level badminton tournaments between May and September 2019. Information including the players’ characteristics, training history, injuries in the previous 12 months, and ankle injury histories were collected. Logistic regression was used for analysis.

Results:

A total of 478 players were included in the study, with 71 ankle injuries, 74 knee injuries, and 48 shoulder injuries reported. The injury incidence rates (per 1000 hours of play) were 0.23 (95% CI, 0.18-0.29) for the ankle, 0.24 (95% CI, 0.19-0.30) for the knee, and 0.16 (95% CI, 0.11-0.20) for the shoulder; 90.1% of ankle injuries, 25.7% of knee injuries, and 33.3% of shoulder injuries were acute. Previous ankle injury was significantly associated with subsequent ankle injury (adjusted Odds Ratio (OR), 3.05; 95% CI, 1.54-6.07; P < .05), knee injury (adjusted OR, 2.03; 95% CI, 1.12-3.69; P < .05), and shoulder injury (adjusted OR, 2.46; 95% CI, 1.26-4.83; P < .05).

Conclusion:

The study results indicated that previous injury to the ankle significantly increased the occurrence of subsequent ankle, knee, and shoulder injuries. Emphasizing protection and prevention of ankle injuries may help lower future injury risk in young badminton players.

Effects of Patellofemoral Pain Syndrome on Changes in Dynamic Postural Stability during Landing in Adult Women

Background

This study investigated the effects of lower limb movements on dynamic postural stability (DPS) during drop landing in adult women with patellofemoral pain syndrome (PFPS).

Methods

Thirty-eight adult women were recruited and divided into two groups, the PFPS group and the control group. The study participants performed a single-leg drop landing from a 30 cm box, and their lower limb movements and DPS were measured. Differences between groups were examined using independent sample t-tests. In addition, stepwise multiple linear regression was used to examine the kinematic parameters that contribute to the DPS.

Results

The PFPS group had significantly lower hip flexion, internal rotation, knee flexion, ankle external rotation, pelvic oblique, tilt, rotation, and higher hip abduction, knee valgus, and ankle plantarflexion. In terms of DPS, the PFPS group had a significantly higher anteroposterior and a lower mediolateral than that of the control group. In the control group, regression analysis revealed a controlled anteroposterior using knee flexion, while the PFPS group controlled mediolateral through ankle plantarflexion.

Conclusions

Patients with PFPS experienced more shock on their knee joint during landing than patients in the control group with greater anteroposterior instability and lower mediolateral instability.

Knee Muscles Strength Can be Improved by Using an Elastic Band as an Assistive Device for Knee-Ankle Complex

BACKGROUND There are various tools and methods used for strength exercise. Elastic bands, one of the resistance exercise tools, have been used for various purposes, including muscle strengthening; however, there is very little evidence supporting their efficacy. The study was performed to investigate the effect of knee-ankle elastic bands on knee muscle strength-related parameters according to sex in healthy adults. MATERIAL AND METHODS This was a cross-sectional study. Twenty-one participants (11 female and 10 male) were studied using a cross-over design. Isokinetic concentric knee extension and flexion strength was measured at 60°/s and 180°/s with and without application of a therapeutic elastic band in the shape of an "8", with knee flexion and ankle dorsiflexion. The variables related to muscle power automatically calculated in the protocol of the isokinetic system were compared according to sex and angular velocity. RESULTS Peak moment (PM), PM/body weight, average power, total work, and the agonist/antagonist ratio, demonstrated significant improvement (P<0.05) at both 60°/s and 180°/s "with" compared to "without" the elastic band according to sex. CONCLUSIONS The use of therapeutic elastic bands in the shape of a figure 8 with knee flexion and ankle dorsiflexion may be used as assistive devices for improving strength in muscles supporting the knee. Further high-quality studies are needed to assess the potential of elastic bands as assistive devices and not merely as exercise tools. Therapeutic elastic bands in the shape of an "8" with knee flexion and ankle dorsiflexion may be useful in sports activities.