The impact of sex and knee injury history on jump-landing patterns in collegiate athletes: a clinical evaluation

Little associations exist between the three commonly used functional screening tests in collegiate athletes

Although an abundant number of studies have investigated the predictability of the commonly used functional screening tests and despite their popularity and applicability, the relationships between these tests have rarely been studied and have not been well established. This study aimed to examine the potential association between the Functional Movement Screen (FMS), Y Balance Test (YBT), and Landing Error Scoring System (LESS). Six hundred twenty-seven Iranian collegiate athletes (347 males, age = 22.63 ± 4.07, weight = 75.98 ± 13.79, height = 181.99 ± 10.15, BMI = 22.84 ± 3.16; and 280 females, age = 22.22 ± 3.37, weight = 60.63 ± 9.58, height = 166.55 ± 6.49, BMI = 21.81 ± 2.84) participated in this study. Following a 5-min warm-up, each participant underwent a standardized screening battery including the FMS, YBT, and LESS, and the scores were recorded and live coded for the statistical analysis, except for the LESS. The LESS tests were video recorded and scored by one expert examiner using an open-source 2D video analysis software (Kinovea- version 0.9.5), afterwards. The Spearman correlation was utilized as a measure for the correlation, and the Mann‒Whitney U test with a significance level of 0.05 was used to check the differences between male and female athletes. The statistical analysis was performed with RStudio 2023.03.0 using R 4.3.1. A small correlation (0.364) was observed between the FMS composite score and the YBT in male athletes. All other pairwise correlations were negligible among male and female athletes, ranging from - 0.096 to 0.294. Reducing the FMS to the component scores targeting the lower extremities did not alter the correlation to the other screening scores. The median FMS composite score in female athletes was significantly higher than that in males (p < 0.001). Negligible correlations exist between the FMS, LESS, and YBT; they do not measure the same values and therefore are irreplaceable with one another. A combination of these tests as a standardized screening battery may potentially better identify injury-predisposed athletes than the application of each test as a stand-alone screening test. Females outperformed males in the FMS test significantly, so sex must be considered a key variable in the FMS studies. Males had slightly higher LESS scores (median difference = 0.5) than females, but this difference is not clinically meaningful. Future research should continue to explore the relationships between various functional screening tests and identify the most effective combinations for comprehensive assessment in different populations and sports disciplines.

Effects of pubertal growth variation on knee mechanics during walking in female and male adolescents

INTRODUCTION

Puberty substantially alters the body's mechanical properties, neuromuscular control, and sex differences therein, likely contributing to increased, sex-biased knee injury risk during adolescence. Female adolescents have higher risk for knee injuries than male adolescents of similar age engaging in similar physical activities, and much research has investigated sex differences in mechanical risk factors. However, few studies address the considerable variation in pubertal growth (timing, pace), knee mechanics, and injury susceptibility within sexes, or the impact of such growth variation on mechanical injury risk.

OBJECTIVES

The present study tested for effects of variation in pubertal growth on established mechanical knee injury risk factors, examining relationships between and within sexes.

METHODS

Pubertal growth indices describing variation in the timing and rate of pubertal growth were developed using principal component analysis and auxological data from serial stature measurements. Linear mixed models were applied to evaluate relationships between these indices and knee mechanics during walking in a sample of adolescents.

RESULTS

Later developing female adolescents with slower pubertal growth had higher extension moments throughout stance, whereas earlier developers had higher valgus knee angles and moments. In male adolescents, faster and later growth were related to higher extension moments throughout gait. In both sexes, faster growers had higher internal rotation moments at foot-strike.

CONCLUSIONS

Pubertal growth variation has important effects on mechanical knee injury risk in adolescence, affecting females and males differently. Earlier developing females exhibit greater injury risk via frontal plane factors, whereas later/faster developing males have elevated risk via sagittal plane mechanisms.

Unsupervised Clustering Techniques Identify Movement Strategies in the Countermovement Jump Associated With Musculoskeletal Injury Risk During US Marine Corps Officer Candidates School

Musculoskeletal injuries (MSKI) are a significant burden on the military healthcare system. Movement strategies, genetics, and fitness level have been identified as potential contributors to MSKI risk. Screening measures associated with MSKI risk are emerging, including novel technologies, such as markerless motion capture (mMoCap) and force plates (FP) and allow for field expedient measures in dynamic military settings. The aim of the current study was to evaluate movement strategies (i.e., describe variables) of the countermovement jump (CMJ) in Marine officer candidates (MOCs) via mMoCap and FP technology by clustering variables to create distinct movement strategies associated with MSKI sustained during Officer Candidates School (OCS). 728 MOCs were tested and 668 MOCs (Male MOCs = 547, Female MOCs = 121) were used for analysis. MOCs performed 3 maximal CMJs in a mMoCap space with FP embedded into the system. De-identified MSKI data was acquired from internal OCS reports for those who presented to the OCS Physical Therapy department for MSKI treatment during the 10 weeks of OCS training. Three distinct clusters were formed with variables relating to CMJ kinetics and kinematics from the mMoCap and FPs. Proportions of MOCs with a lower extremity and torso MSKI across clusters were significantly different (p < 0.001), with the high-risk cluster having the highest proportions (30.5%), followed by moderate-risk cluster (22.5%) and low-risk cluster (13.8%). Kinetics, including braking rate of force development (BRFD), braking net impulse and propulsive net impulse, were higher in low-risk cluster compared to the high-risk cluster (p < 0.001). Lesser degrees of flexion and shorter CMJ phase durations (braking phase and propulsive phase) were observed in low-risk cluster compared to both moderate-risk and high-risk clusters. Male MOCs were distributed equally across clusters while female MOCs were primarily distributed in the high-risk cluster. Movement strategies (i.e., clusters), as quantified by mMoCap and FPs, were successfully described with MOCs MSKI risk proportions between clusters. These results provide actionable thresholds of key performance indicators for practitioners to use for screening measures in classifying greater MSKI risk. These tools may add value in creating modifiable strength and conditioning training programs before or during military training.

Factors influencing the Landing Error Scoring System: Systematic review with meta-analysis

OBJECTIVES

Systematically review the literature addressing age, sex, previous injury, and intervention program as influencing factors of the Landing Error Scoring System.

DESIGN

Systematic review with meta-analysis.

METHODS

Three databases (PubMed, Web of Science®, and Scopus®) were searched on 1 April 2020. Original studies using the Landing Error Scoring System as primary outcome and exploring age, sex, previous injury, and intervention program were included, assessed for risk of bias, and critically appraised. Three meta-analyses were performed using one random and two mixed effect models with dependent variables: sex, previous injury and intervention program, respectively. Grading of Recommendations Assessment, Development and Evaluation was used to evaluate the strength of the evidence. PROSPERO registration number CRD42018107210.

RESULTS

Fifty-two studies were included. Pooled data indicated that females have higher Landing Error Scoring System scores than males (p<0.001, mean difference=0.6 error). Participants with previous anterior cruciate ligament injury have higher LESS scores than healthy controls (p=0.004, mean difference 1.2 error). Neuromuscular training programs lasting a minimum of six weeks and other intervention programs decrease Landing Error Scoring System scores (p<0.001, mean difference 1.2 error and p=0.042, mean difference 0.5 error, respectively). There is limited evidence suggesting that age may influence Landing Error Scoring System scores in clinically meaningful manner. Overall, Grading of Recommendations Assessment, Development and Evaluation ratings suggest very low strength of evidence.

CONCLUSIONS

History of anterior cruciate ligament injury and undertaking neuromuscular training for a minimum of six weeks meaningfully altered Landing Error Scoring System scores. These findings, however, should be interpreted cautiously considering the very low Grading of Recommendations Assessment, Development and Evaluation rating of the evidence.

Relationship Between Age at Adult Height and Knee Mechanics During a Drop Vertical Jump in Men

Background:

Anterior cruciate ligament (ACL) injuries are relatively common among younger athletes, with significant physical, psychological, and financial consequences. Research has largely focused on female athletes by identifying specific risk factors for an ACL injury, including variation in pubertal growth timing. There is less known about risk factors in males, and little is known about the effects of pubertal development on ACL injury risk in men.

Purpose/Hypothesis:

The purpose of this study was to analyze the relationship between an indicator of pubertal growth timing (age at adult height) and biomechanical risk for ACL injuries in men. We hypothesized that earlier age at adult height is correlated with riskier landing biomechanics during a drop vertical jump (DVJ) in men.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 21 recreationally active male students (age range, 20-33 years) were included. Participants completed a questionnaire on age at adult height and limb dominance, and anthropometric measurements were taken. There were 6 DVJ tests performed, with participants landing on a force plate while digital cameras recorded kinematic data from retroreflective markers placed according to the Helen Hayes marker system. Primary outcomes were sagittal and frontal plane knee kinematics and kinetics during contact. Data were analyzed using Pearson product-moment correlation.

Results:

In both limbs, age at achieving adult height was significantly negatively correlated with knee flexion/extension angle at toe-off (dominant: r = –0.79, P < .01; nondominant: r = –0.74, P < .01) and with peak flexion (dominant: r = –0.63, P < .01; nondominant: r = –0.70, P < .01) and extension (dominant: r = –0.66, P < .01; nondominant: r = –0.56, P = .01) angles during contact. In the nondominant limb, age at adult height was significantly negatively correlated with varus/valgus angle at initial contact (r = –0.43; P = .05) and toe-off (r = –0.44; P = .04) and was positively correlated with peak varus moment during contact (r = 0.42; P = .06). Age at adult height was also positively correlated with peak vertical ground-reaction force (r = 0.58; P < .01).

Conclusion:

Later age at adult height was correlated with riskier landing profiles in this study. This suggests that males with later or longer pubertal growth may have increased mechanical risk for ACL injuries. A better understanding of the effects of pubertal growth on landing biomechanics can improve the early identification of male athletes at greater risk for injuries.

Movement Technique During Jump-Landing Differs Between Sex Among Athletic Playing Surfaces

Pryor, JL, Burbulys, ER, Root, HJ, and Pryor, RR. Movement technique during jump-landing differs between sex among athletic playing surfaces. J Strength Cond Res XX(X): 000-000, 2020-Whether athletic surface type affects movement technique, a causal factor for lower extremity injury, is unclear. This study evaluated the influence of 4 common athletic surfaces on movement technique using the Landing Error Scoring System (LESS). Secondarily, we aimed to evaluate differences in movement technique between men and women among surfaces. Recreationally active men and women (n = 38) completed jump-landing tests on 4 common athletic surfaces in a quasi-randomized crossover fashion. Vertical jump height, perceptual fatigue, and muscle soreness were evaluated before jump-landing movement analyses and were similar across testing sessions (p > 0.05). Men achieved higher LESS scores on hardwood and artificial pellet turf compared with women (p ≤ 0.037). Women exhibited lower LESS scores on grass and artificial turf vs. concrete (p ≤ 0.048). Data indicate differential lower extremity movement technique and therefore injury risk across athletic surface types and sex, challenging the generalizability of the LESS construct. Athletic playing surface should be considered during movement technique assessment and implementation of injury prevention programs.

Is the Landing Error Scoring System Reliable and Valid? A Systematic Review

CONTEXT

The Landing Error Scoring System (LESS) is a clinical tool often used in research and practice to identify athletes presenting high injury-risk biomechanical patterns during a jump-landing task.

OBJECTIVE

To systematically review the literature addressing the psychometric properties of the LESS.

DATA SOURCES

Three electronic databases (PubMed, Web of Science, and Scopus) were searched on March 28, 2018, using the term "Landing Error Scoring System."

STUDY SELECTION

All studies using the LESS as main outcome measure and addressing its reliability, validity against motion capture system, and predictive validity were included. Original English-language studies published in peer-reviewed journals were reviewed. Studies using modified versions of the LESS were excluded.

STUDY DESIGN

Systematic literature review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Study design, population, LESS testing procedures, LESS scores, statistical analysis, and main results were extracted from studies using a standardized template.

RESULTS

Ten studies met inclusion criteria and were appraised using Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies. The overall LESS score demonstrated good-to-excellent intrarater (intraclass correlation coefficient [ICC], 0.82-0.99), interrater (ICC, 0.83-0.92), and intersession reliability (ICC, 0.81). The validity of the overall LESS score against 3-dimensional jump-landing biomechanics was good when individuals were divided into 4 quartiles based on LESS scores. The validity of individual LESS items versus 3-dimensional motion capture data was moderate-to-excellent for most of the items addressing key risk factors for anterior cruciate ligament (ACL) injury. The predictive value of the LESS for ACL and other noncontact lower-extremity injuries remains uncertain based on the current scientific evidence.

CONCLUSION

The LESS is a reliable screening tool. However, further work is needed to improve the LESS validity against motion capture system and confirm its predictive validity for ACL and other noncontact lower-extremity injuries.

The Impact of Knee Injury History on Health-Related Quality of Life in Adolescent Athletes

CONTEXT

Current evidence suggests that, despite returning to full participation, physically active adults with a previous knee injury experience lower health-related quality of life (HRQOL) than those with no knee injury history. It is unknown if this relationship is present in adolescent athletes.

OBJECTIVE

To determine the impact of knee injury history on HRQOL in adolescent athletes who were medically cleared for full participation.

DESIGN

Cross-sectional.

SETTING

Athletic training clinics.

PARTICIPANTS

A convenience sample of 183 adolescent athletes, who were medically cleared for full participation, were grouped by self-report of a previous knee injury: positive knee injury history (HIS; n = 36, age = 15.7 [1.4] y, height = 168.0 [11.9] cm, and weight = 71.8 [11.9] kg) and no knee injury history (NO-HIS; n = 147, age = 15.5 [1.4] y, height = 166.0 [10.5] cm, and weight = 67.6 [14.6] kg).

INTERVENTIONS

Participants completed the Pediatric International Knee Documentation Committee form and Pediatric Quality of Life Inventory during their preparticipation examination.

MAIN OUTCOME MEASURES

Generalized linear models were used to compare group differences for the total and subscale scores of the Pediatric International Knee Documentation Committee and Pediatric Quality of Life Inventory.

RESULTS

Main effects of injury group indicated that the HIS group reported significantly lower scores than the NO-HIS group for the Pediatric International Knee Documentation Committee total score (P < .001; HIS = 79.2 [21.7], NO-HIS = 95.8 [8.6]) and for the Pediatric Quality of Life Inventory total (P = .001; HIS = 85.7 [10.9], NO-HIS = 90.9 [7.3]), physical functioning (P = .002; HIS = 86.7 [13.6], NO-HIS = 92.1 [8.2]), school functioning (P = .01; HIS = 80.6 [12.4], NO-HIS = 86.8 [12.2]), and social functioning (P = .01; HIS = 89.3 [12.4], NO-HIS = 94.6 [8.9]) scores. No group differences were reported for the emotional functioning subscale (P = .13; HIS = 85.7 [17.7], NO-HIS = 89.7 [13.1]). No interactions or main effects of sex were reported (P > .05).

CONCLUSIONS

Our findings suggest that, despite returning to full sport participation, adolescent athletes with a previous knee injury generally experience lower HRQOL than their peers with no knee injury history, specifically for knee-specific HRQOL, physical functioning, school functioning, and social functioning. Our results are similar to previous findings reported in college athletes and military cadets.

Functional Movement Screen Factorial Validity and Measurement Invariance Across Sex Among Collegiate Student-Athletes

Gnacinski, SL, Cornell, DJ, Meyer, BB, Arvinen-Barrow, M, and Earl-Boehm, JE. Functional Movement Screen factorial validity and measurement invariance across sex among collegiate student-athletes. J Strength Cond Res 30(12): 3388-3395, 2016-The Functional Movement Screen (FMS) is a screening tool used to evaluate functional movement quality and subsequent musculoskeletal injury risk. Despite recent research on the factorial validity of the FMS, no confirmatory factor analysis (CFA) has been conducted to examine measurement invariance across sex among student-athletes. The primary purpose of the current study was to confirm the factor structure of the FMS measurement model in a collegiate student-athlete population. It was hypothesized that the 1-factor model would demonstrate better model fit than the recently proposed 2-factor model. The secondary purpose of the study was to examine FMS measurement invariance across sex using the previously identified measurement model. It was hypothesized that FMS measurement invariance would hold across sex. Male (n = 88) and female (n = 88) collegiate student-athletes completed FMS screening during the off-season. Factorial validity was examined using CFA procedures, and model parameters were estimated using maximum likelihood estimation. Measurement invariance was examined by comparison of fit indices between hierarchically constrained models. Results revealed support for both the 1- and the 2-factor models; however, the 2-factor model failed to fit the data significantly better than the 1-factor model. Results also indicated that measurement invariance did not hold across sex, indicating that the FMS sum score construct is not measured equivalently in male and female populations. Collectively, results provide evidence for the use of the unidimensional FMS sum score among collegiate student-athletes, yet prompt caution because it relates to the evaluation of sex differences in sum or movement pattern scores.

Use of clinical movement screening tests to predict injury in sport

Clinical movement screening tests are gaining popularity as a means to determine injury risk and to implement training programs to prevent sport injury. While these screens are being used readily in the clinical field, it is only recently that some of these have started to gain attention from a research perspective. This limits applicability and poses questions to the validity, and in some cases the reliability, of the clinical movement tests as they relate to injury prediction, intervention, and prevention. This editorial will review the following clinical movement screening tests: Functional Movement Screen™, Star Excursion Balance Test, Y Balance Test, Drop Jump Screening Test, Landing Error Scoring System, and the Tuck Jump Analysis in regards to test administration, reliability, validity, factors that affect test performance, intervention programs, and usefulness for injury prediction. It is important to review the aforementioned factors for each of these clinical screening tests as this may help clinicians interpret the current body of literature. While each of these screening tests were developed by clinicians based on what appears to be clinical practice, this paper brings to light that this is a need for collaboration between clinicians and researchers to ensure validity of clinically meaningful tests so that they are used appropriately in future clinical practice. Further, this editorial may help to identify where the research is lacking and, thus, drive future research questions in regards to applicability and appropriateness of clinical movement screening tools.

Previous Knee Injury and Health-Related Quality of Life in Collegiate Athletes

CONTEXT

  Patient-rated outcome measures (PROMs) capture changes that are important and meaningful to patients, such as health-related quality of life (HRQOL). Although group differences in HRQOL have been reported, little is known about the effect of injury history on HRQOL in collegiate athletes.

OBJECTIVE

  To determine whether knee-specific function (International Knee Documentation Committee Subjective Knee Evaluation Form [IKDC]) and HRQOL (Short Form 12 [SF-12]) differs in collegiate athletes based on sex and the severity of a previous knee injury.

DESIGN

  Cross-sectional study.

SETTING

  Athletic training facilities.

PATIENTS OR OTHER PARTICIPANTS

  Healthy collegiate athletes (n = 263) were grouped based on self-report of a previous knee injury: severe (n = 47), mild (n = 40), and no (n = 176) knee injury.

INTERVENTION(S)

  Participants completed the IKDC and SF-12 during their preparticipation examinations.

MAIN OUTCOME MEASURE(S)

  Generalized linear models were used to assess interactions and main effects of all scores.

RESULTS

  An interaction effect was observed for the SF-12 role physical subscale (P = .02), with men in the mild- and severe-injury groups reporting worse scores than men with no injury history. We noted a main effect for injury group for the IKDC total score (P < .001) and SF-12 physical functioning (P = .04) and role emotional (P = .04) subscales, with the severe-injury group reporting worse scores than the mild- and no-injury groups. No main effects of sex were reported (P > .05).

CONCLUSIONS

  Despite returning to full participation, collegiate athletes who previously sustained severe knee injuries tended to report worse knee-specific function and less ability to complete activities due to physical health. In addition, individuals with a history of severe knee injury tended to report more emotional concerns than athletes with a history of mild or no knee injury. Region-specific PROMs may be more sensitive in detecting deficits than generic PROMs after return to full participation. Researchers should investigate the role of PROMs, particularly region-specific PROMs, as potential screening tools for clinical care.