Landing Error Scoring System Score Research Articles

COMPARISON OF INTER-SESSION, INTRA-RATER AND INTER-RATER RELIABILITY OF SINGLE AND DOUBLE LEG LANDING ERROR SCORING SYSTEM USING DIFFERENT CALCULATION METHODS

INTRODUCTION & AIMS The Landing Error Scoring System (LESS) is used for screening noncontact anterior cruciate ligament (ACL) injury risk. The LESS is deemed a valid and reliable indicator of landing biomechanics that predict noncontact ACL injuries. We have sought to validate a Single-Leg Landing Error Scoring System (SLESS) against the established LESS. There are seven distinct calculation methods for final LESS scores, adding variability to the original version and the risk of misinterpreting results. This study used different calculation methods to investigate the inter-session, intra-rater and inter-rater reliability of the SLESS and LESS scores. METHODS Thirty-five team sports players performed four drop jump landing variations (dominant leg, non-dominant leg, double-leg and cognitive loading drill with double-leg) over three sessions. Sessions 1 and 2 were conducted on the same day, with Session 3 a week later. Video footage from frontal and sagittal views captured all landings. Three professionals scored recorded trials using standard SLESS and LESS protocols. One scorer assessed intra-session and inter-session reliability, while three evaluated inter-rater reliability. The final SLESS and LESS scores were calculated using original version/OG, average of 3 trials-AV, worst trial/WT, best score/BS, first trial/FT, last trial/LT, error present in at least two of three trials/TT). Reliability was assessed using intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV) with 95% confidence intervals. RESULTS The study observed acceptable inter-session reliability across single-leg and double-leg drop jump landing tasks using all seven calculation methods (SLESS: ICC=0.80-0.91, SEM=1.07-1.10, CV=6.5-10.1%; LESS: ICC=0.63-0.90, SEM=1.06-1.11, CV=5.7-11.5%). The study also demonstrated acceptable intra-rater reliability for all tasks using all calculation methods (SLESS: ICC=0.86-0.94, SEM=1.05-1.08, CV=5.0-8.5%; LESS: ICC=0.74-0.93, SEM=1.04-1.08, CV=4.2-8.5%). In addition, acceptable inter-rater reliability was shown for all tasks using all calculation methods (SLESS: ICC=0.69-0.83, SEM=1.11-1.18, CV=10.5-18.0%; LESS: ICC=0.54-0.82, SEM=1.10-1.20, CV=10.3-20.3%). CONCLUSION The study indicates the reliability of all seven calculation methods for SLESS and LESS scores. Precise specification of the chosen calculation method is crucial for practitioners and researchers.

Cognitive-Motor Dual-Task Performance of the Landing Error Scoring System.

The Landing Error Scoring System (LESS) is a common assessment used to determine biomechanical landing errors. However, this assessment is completed as a single motor task, which does not require additional attentional resources. It is unclear if the LESS can be used to detect cognitive-motor interference (i.e., dual-task cost) in biomechanical errors associated with lower extremity injury. To determine if the LESS is a suitable clinical assessment of dual-task performance in uninjured females and to evaluate whether specific landing criteria are more affected by an additional cognitive load than others. Observational Cross-Sectional Design. Setting: University research laboratory. Twenty uninjured, physically active females participated. Intervention(s): Participants performed the LESS under three different conditions: baseline landing with no cognitive distraction (Single), a visual-based dual-task (Visual), and a number-based dual-task (Number). Mean sagittal, frontal, and total LESS scores were compared between conditions using a one-way repeated measures analysis of variance with Tukey post hoc corrections. Cohen's d effect sizes with 95% confidence intervals were used to determine the magnitude of differences. The frequency of errors for each individual LESS item under the three conditions were compared using Chi-Squared analyses. Participants exhibited greater sagittal plane (P=.013, d=0.91 [0.26, 1.56]) and total (P=.008, d=1.03 [0.37, 1.69]) errors during the Visual condition compared to the Single condition. Frontal plane errors were significantly greater during the Number condition compared to the Single condition (P=.008, d=1.03 [0.37, 1.69]). The frequency of errors observed for each LESS item did not statistically differ between conditions (all P>.05). The LESS was able to detect a dual-task cost in landing errors during both the Visual and Number conditions. We recommend developing clinically-oriented solutions to incorporate similar dual- task paradigms in traditional injury risk reduction programs.

Evaluation of the Anterior Cruciate Ligament Injury Risk During a Jump-Landing Task Using 3-Dimensional Kinematic Analysis Versus the Landing Error Scoring System.

The Landing Error Scoring System (LESS) has been utilized on the field or in the clinic to identify patients with an increased risk for anterior cruciate ligament (ACL) injuries; however, its validity and efficacy have not been fully confirmed. To assess the efficacy of the LESS in identifying the ACL injury risk by examining the correlation between the LESS score and motion patterns on 3-dimensional kinematic analysis. Controlled laboratory study. The jump-landing motion was analyzed for 16 female basketball or badminton players who volunteered to participate in the study. All study participants were aged 19 or 20 years. The sequence of motion was evaluated with the LESS, while kinematic data were simultaneously acquired with a 3-dimensional motion analysis system utilizing the point cluster method. The correlation between the LESS score and knee kinematics was statistically analyzed. When a LESS score ≥6 was defined to be a risk factor for ACL injuries, 7 of the 16 participants (43.8%) were found to exhibit risky motion patterns. Significant correlations were noted between the LESS score and knee valgus (r = 0.87; P < .0001) and internal tibial rotation (r = 0.57; P = .02) at landing. By contrast, a substantial variability was present in knee flexion, showing no correlation with the LESS score. Significant correlations were found between the LESS score and knee valgus and internal tibial rotation during a jump-landing task. The LESS can be regarded as an effective measure to identify risky motion patterns that may increase the likelihood of ACL injuries.

Effect of Footwear Versus Barefoot on Double-Leg Jump-Landing and Jump Height Measures: A Randomized Cross-Over Study.

Assessing individuals in their own athletic footwear in clinics is common, but can affect movement, performance, and clinical measures. The aim was to compare overall Landing Error Scoring System (LESS) scores, injury risk categorization, specific LESS errors, and jump heights between habitual athletic footwear and barefoot conditions. Randomized cross-over laboratory study. Eighty healthy individuals (55% male) completed the LESS following standard procedures (i.e., land from a 30-cm box to a distance of 50% of body height and then jump upwards maximally). Participants performed the LESS three times in two randomized conditions: footwear and barefoot. LESS data were extracted from 2D videos to compare group-level mean LESS scores, group-level and individual-level injury risk categorization (5-error threshold), specific landing errors, and jump heights between conditions. LESS scores were significantly greater (0.3 errors, p=0.022) and jump heights were significantly lower (0.6 cm, p=0.029) in footwear than barefoot, but differences were trivial (d = 0.18 and -0.07, respectively) and not clinically meaningful. Although the number of high injury-risk participants was not statistically different at a group level (p=1.000); 27 individuals (33.8%) exhibited a clinically meaningful difference between conditions of one error or more in LESS score, categorization was inconsistent for 16.3% of individuals, and four of the 17 landing errors significantly differed between conditions. At a group level, habitual athletic footwear does not meaningfully influence LESS scores, risk categorization, or jump height. At an individual level, footwear can meaningfully affect LESS scores, risk categorization, and alter landing strategies. Use of consistent protocol and footwear is advised for assessing movement patterns and injury risk from the LESS given the unknown predictive value of this test barefoot. Level 3.©The Author(s).

Using a target as external focus of attention results in a better jump-landing technique in patients after anterior cruciate ligament reconstruction – A cross-over study

BackgroundImproving jump-landing technique during rehabilitation is important and may be achieved through different feedback techniques, i.e., internal focus of attention (IF) or external focus of attention using a target (EF). However, there is a lack of evidence on the most effective feedback technique after anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to investigate the potential difference in jump-landing techniques between IF and EF instructions in patients after ACLR. MethodsThirty patients (12 females, mean age 23.26 ± 4.91 years) participated after ACLR. Patients were randomly assigned into two groups that each followed a different testing sequence. Patients performed a drop vertical jump-landing test after receiving instructions with varying types of focus of attention. The Landing Error Scoring System (LESS) assessed the jump-landing technique. ResultsEF was associated with a significantly better LESS score (P < 0.001) compared with IF. Only EF instructions led to improvements in jump-landing technique. ConclusionUsing a target as EF resulted in a significantly better jump-landing technique than IF in patients after ACLR. This indicates that increased use of EF could or might result in a better treatment outcome during ACLR rehabilitation.

The Effect of Stretching, Foam Rolling, and FIFA 11+ Warm-ups on Performance and Pain in Athletes with Knee Pain

Background: Patellofemoral pain syndrome (PFPS) is the most prevalent disease of the knee. The purpose of this study was to compare the acute effects of various warm-up methods on several performance measures and pain intensity in athletes with and without PFPS.&#x0D; Methods: This clinical trial study included 18 to 24-year-old professional female athletes with or without PFPS. Both groups performed warm-up protocols, including general stretching, foam rolling, and Federation Internationale de Football Association (FIFA) 11+ warm-up exercises in three test sessions simultaneously. The data collection procedure was implemented on three separate days in one week. Pain intensity was measured using the Visual Analogue Scale (VAS). Countermovement jump (CMJ) and squat jump (SJ) to measure the stretch-shortening cycle (SSC) and Landing Error Scoring System (LESS) were examined before and after each session.&#x0D; Results: No significant difference was observed between the effect of different warm-ups in groups with and without PFPS regarding the use of the SSC (P = 0.185), while there were significant differences in the effect of various warm-up protocols on LESS (P &lt; 0.001) and pain scores (P &lt; 0.001).&#x0D; Conclusion: Using the foam roller as a warm-up method can decrease the pain intensity in athletes with PFPS but may increase their LESS score. In addition, there was no difference in the effect of various warm-up methods on the SSC between athletes with and without PFPS. Finally, it seems that foam rolling should be used with more caution as a part of warming up in athletes with PFPS.

The Impact of a Novel Neuromuscular Training Program on Leg Stiffness, Reactive Strength, and Landing Biomechanics in Amateur Female Rugby Players

This randomized control study aimed to assess 12 weeks of a novel neuromuscular training program (KneeRugbyWomen) on jump-related biomechanical variables in amateur female rugby players. Twenty-four participants were randomly allocated to either an experimental group (EG; n = 12, age: 20.05 ± 4.43 yrs., height: 166.54 ± 4.46 cm, weight: 64.65 ± 6.44 kg) or a control group (CG; n = 12, age: 20.04 ± 4.88 yrs., height: 166.83 ± 7.30 cm, weight: 69.83 ± 12.84 kg). Participants were tested before and after a 12-week intervention for jump-related biomechanical variables (leg stiffness, Reactive Strength Index (RSI), and landing mechanics using the Landing Error Scoring System (LESS)). A significant increase in RSI was found in EG (p = 0.012, r = 0.70, large effect). At post-testing, players in EG had significantly greater RSI scores compared to CG at post-intervention (p = 0.007, r = 0.55, large effect). LESS scores of CG were significantly greater compared to EG at pre-intervention (p = 0.008, r = 0.55, large effect) and post-intervention (p = 0.003, r = 0.60, large effect). Results of this study demonstrate a positive effect of the KneeRugbyWomen training program on RSI, which has been previously associated with increased ACL injury risk in female players.

Curves and kinematics: Relationship between the force-time curve and landing ability.

Anterior cruciate ligament (ACL) injuries have a significant impact on athletic performance and long-term quality of life. Force plates and qualitative screening tools are feasible and effective screening methods to identify abnormal movement quality associated with increased injury risk. Comparing qualitative assessments of landing ability with force-time curves, may detect unique differences between safe and high-risk athletic movement patterns. The aim of this study was to determine low- and high-risk landing ability from qualitive landing assessments and to examine the resulting force-time curves using functional principal component analysis (fPCA). Thirty-one healthy academy athletes (10 males and 21 females) completed double- and single-leg dominant and non-dominant jump-landing-rebound tasks. All movements were filmed in multiple-planes, and vertical ground reaction forces (vGRF) were simultaneously collected. The Landing Error Scoring System (LESS) and Single-Leg Landing Error Scoring System (SL-LESS) were used to score landing footage. From these scores, athletes were categorized into low-risk and high-risk groups for further analysis. fPCA was used to examine differences between landing quality groups force-time curves. Compared to high-risk landers, low-risk landers demonstrated significantly longer contact times across all movements. Scores from fPC1 revealed safe and high-risk landing techniques expose athletes to significantly different loading patterns during double- and single-leg dominant movements. A significant positive relationship was observed between fPC1 and LESS scores, however this relationship was not observed in both single-leg landing scores. Where possible incorporating curve analysis methods like fPCA into multi-faceted screening approaches may help practitioners uncover unique insights into athletic loading strategies.

Effect of an overhead goal on landing error scoring system and jump height measures

ObjectivesCompare overall Landing Error Scoring System (LESS) scores, risk categorisation, specific LESS errors, and double-leg jump-landing jump heights between overhead goal and no goal conditions. DesignRandomised cross-over. SettingLaboratory. Participants76 (51% male). Main outcome measuresParticipants landed from a 30-cm box to 50% of their body height and immediately jumped vertically for maximum height. Participants completed three trials under two random-ordered conditions: with and without overhead goal. Group-level mean LESS scores, risk categorisation (5-error threshold), specific landing errors, and jump heights were compared between conditions. ResultsMean LESS scores were greater (0.3 errors, p < 0.001) with the overhead goal, but this small difference was not clinically meaningful. Similarly, although the number of high-risk participants was greater with the overhead goal (p = 0.039), the 9.2% difference was trivial. Participants jumped 2.7 cm higher with the overhead goal (p < 0.001) without affecting the occurrence of any specific LESS errors. DiscussionPerforming the LESS with an overhead goal enhances sport specificity and elicits greater vertical jump performances with minimal change in landing errors and injury-risk categorisation. Adding an overhead goal to LESS might enhance its suitability for injury risk screening, although the predictive value of LESS with an overhead goal needs confirmation.

Preventive Training Program Feedback Complexity, Movement Control, and Performance in Youth Athletes.

Preventive training programs (PTPs) reduce injury risk by improving movement control. Corrective feedback is important; however, many cues at once may be too complicated for athletes. To compare movement control and long-jump (LJ) changes in youth athletes participating in a season-long PTP, with simplified feedback, traditional feedback, or a warmup of the coaches' choosing. Cluster-randomized controlled trial. Soccer fields. A total of 420 athletes (simplified feedback = 173, traditional feedback = 118, and control = 129; age = 11 ± 3 years). Teams were randomized into the simplified PTP, traditional PTP, or control group. Simplified and traditional PTPs lasted 10 to 12 minutes and used the same exercises. The simplified PTP provided only sagittal-plane feedback (eg, "get low"), and the traditional PTP provided feedback targeting all motion planes (eg, "don't let your knees cave inward"). Research assistants administered the PTP warmups 2 to 3 times/week for the season. Control team coaches chose and ran their own warmup strategies. Participants completed 4 sessions (preseason [PRE], postseason [POST] at approximately 8 weeks after PRE, retention 1 [R1] at 6 weeks postseason, and retention 2 [R2] at 12 weeks postseason). They performed 3 trials of a jump-landing task, which was evaluated using the Landing Error Scoring System (LESS) and 2 recorded standing LJ trials at each test session. A time series panel was used to evaluate group differences across time points for the LESS and LJ. Change score analyses revealed improvements in the LESS score from PRE to POST for all groups. Improvements from PRE were retained at R1 and R2 for the intervention groups (simplified and traditional). The traditional group demonstrated better LJ performance at POST (P < .001) and R1 (P = .049) than the simplified or control group. Simplified cues were as effective as traditional cues in improving LESS scores from PRE to POST season. Participating in PTPs, regardless of their complexity, likely provides movement benefits.

Association Between Landing Error Scoring System (LESS) Items and the Incidence Rate of Lower Extremity Stress Fracture.

Background:Lower extremity stress fracture injuries are a major cause of morbidity in physically active populations. The ability to screen for modifiable risk factors associated with injury is critical in developing injury-prevention programs.Purpose:To determine if baseline Landing Error Scoring System (LESS) scores are associated with the incidence rate of lower extremity stress fracture.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 1772 participants with no history of lower extremity stress fracture were included. At preinjury baseline, the authors conducted a lower extremity movement assessment during a jump-landing task using the LESS. Incident lower extremity stress fractures were identified during a 4-year follow-up period. Potential incident cases were reviewed by 2 sports medicine fellowship–trained orthopaedic surgeons blinded to baseline LESS data. Univariate and multivariable Poisson regression models were used to estimate the association between baseline total LESS scores, individual LESS items, and the incidence rate ratio (IRR) of lower extremity stress fracture.Results:A total of 94 incident lower extremity stress fractures were documented, for a 5.3% (95% CI, 4.3%-6.5%) cumulative incidence. The overall LESS score was associated with the incidence rate of lower extremity stress fracture. For every additional movement error documented at baseline, there was a 15% increase in the incidence rate of lower extremity stress fracture (IRR, 1.15 [95% CI, 1.02-1.31]; P = .025). In univariate analyses, ankle flexion, stance width, asymmetrical landing, and trunk flexion at initial contact, in addition to overall impression, were associated with the incidence rate of stress fracture. After controlling for sex and year of entry into the study cohort, participants who consistently landed flat-footed or heel-to-toe were 2.33 times (95% CI, 1.36-3.97; P = .002) more likely to sustain a lower extremity stress fracture. Similarly, participants who consistently demonstrated asymmetric landing at initial contact were 2.53 times (95% CI, 1.34-4.74; P = .004) more likely to sustain a stress fracture.Conclusion:Components of the LESS may be associated with increased lower extremity stress fracture risk and may be helpful in efficiently assessing high-risk lower extremity biomechanics in large groups.

Age-Related Changes in Landing Mechanics in Elite Male Youth Soccer Players: A Longitudinal Study

The aim of this longitudinal observational study was to examine the age differences in jump landing kinematics in 13–17-year-old male soccer players. Landing technique was evaluated in three consecutive seasons in U14 (n = 15) and the U16 (n = 10) competition age groups using the Landing Error Scoring System (LESS). For the LESS, ANOVA revealed no significant interaction effect (p = 0.81, η2 = 0.009) or main effect for groups (p = 0.15, η2 = 0.086), but a significant year effect was observed (p &lt; 0.001, η2 = 0.265). The LESS score in the U14 group decreased significantly in the second year (5.7 ± 1.9, p = 0.006, d = 0.84) and in the third year (5.9 ± 2.0, p = 0.020, d = 0.70) compared to the first year (7.1 ± 1.7). The LESS score in the U16 group decreased significantly in the second year (5.1 ± 0.9 points, p = 0.034, d = 0.77) and in the third year (4.9 ± 1.4, p = 0.013, d = 0.92) compared to the first year (6.4 ± 1.2). This trend was supported by the results of the separate assessment of the sagittal plane joint displacement. These findings support previous limited findings from cross-sectional studies, which point to improved landing mechanics during maturation. However, the LESS scores in both groups indicate that players who were around and/or post-peak height velocity during the observed periods may be considered “at-risk”, and suggest that preventive training programs should be introduced at earlier stages of players’ development.

Relationship Between Ankle Dorsiflexion Mobility and Functional Return to Sport Test Performance in Athletes Who Have Undergone ACL Reconstruction

Background:Limited ankle dorsiflexion (DF) range has been associated with knee injuries and altered biomechanics during functional squatting and landing tasks. Prior studies correlating weight-bearing DF with altered landing mechanics have primarily used advanced motion capture technology, with limited research using clinically validated scoring tools.Hypothesis/Purpose:To assess the relationship between decreased DF and functional testing performance in youth athletes who have undergone anterior cruciate ligament reconstruction (ACLR).Methods:A retrospective review of standardized data was conducted on patients who had undergone ACLR at a pediatric sports medicine practice that had completed functional testing between December 2017 and November 2020. Patients with testing completed at a minimum of five months post-operatively, and who planned to return-to-sport (RTS) were included. Functional testing included validated protocols for the Y-Balance Test (YBT) and the Landing Error Scoring System (LESS), as well as a modified Single-Leg Squat Endurance Test (SLSET) utilizing the VAIL sports test scoring criteria. DF was measured in a weight-bearing lunge position off the front foot. Subjects were categorized into a pass or fail group based on their YBT and LESS scores (YBT≥94%, LESS≤4), and t-tests were performed to identify significant differences in DF between groups (α=0.05). Lastly, Pearson correlations were performed to identify potential relationships between DF and SLSET total score as well as normalized anterior reach collected as a component of the YBT (α=0.05).Results:303 patients (148 (48.8%) males, 15.94±2.15 years, 7.46±2.11 months post-operative) were included for analysis. Significant correlations were identified between DF and YBT composite score (p <0.001) and LESS total score (p <0.001; Table 1). Additionally, positive relationships were found between DF and both SLSET total score (p <0.001, r = 0.296) and anterior reach (p <0.001; r =0.400). Average values for DF, YBT, and LESS can be found in Table 2.Conclusion:In this pediatric ACLR population, decreased ankle dorsiflexion is associated with high risk movement patterns during functional testing. This study adds to the literature by identifying clinically applicable DF thresholds associated with passing scores on the YBT and LESS functional tests. Clinical interventions aimed at improving ankle dorsiflexion to >36° may be an important component of ACL rehabilitation.Table 1.Ankle dorsiflexion (Mean ± SD) across patients and by functional test scoresTable 2.Average values per measure (Note: Asymm = side-to-side differences)

Biomechanical features of drop vertical jump are different among various sporting activities

BackgroundRisk for non-contact anterior cruciate ligament (ACL) injury can be assessed based on drop vertical jump (DVJ). However, biomechanics of DVJ may differ with various sporting activities. The purpose of the present study was to clarify whether biomechanical features of DVJ are different among various sporting activities in female athletes.MethodsA total of 42 female athletes, including 25 basketball, 8 soccer and 9 volleyball players, participated in the current investigation. DVJ was done for each female athlete using a three-dimensional motion analysis system which consisted of six cameras, two force plates and 46 retro-reflective markers. Kinematic and kinetic data were recorded for both limbs in each athlete. Simultaneously, frontal and sagittal plane views of the DVJ were recorded using two different high-resolution video cameras to evaluate Landing Error Scoring System (LESS) score. Three-dimensional biomechanical parameters at the knee joint and LESS were compared among three different sporting activities using ANOVA or Kruskal–Wallis test after confirming normality assumption. Thereafter post hoc Tukey or Steel–Dwass was utilized for multiple comparison.ResultsSoccer players had better LESS score, and peak knee flexion angle was significantly larger in soccer players compared to the other sports. In addition, knee abduction angle at initial contact (IC), peak knee abduction angle, knee internal rotation angle, and knee abduction moment within 40 ms from IC were significantly smaller in soccer players, compared to basketball players. In terms of volleyball players, knee abduction angle at IC and knee internal rotation angle at IC were significantly larger than soccer players, whereas no significant biomechanical differences were found between basketball and volleyball players.ConclusionsFrom the present study, female basketball and volleyball players have worse LESS score, smaller peak knee flexion angle, greater knee abduction angle at IC and greater knee internal rotation angle at IC, compared to female soccer players. Thus, female basketball and volleyball players may have an increased risk of non-contact ACL injury during the jump-landing task, compared to soccer players. Biomechanics of DVJ depends on characteristics of the athlete's primary sport.

Are Elite Collegiate Female Athletes PRIME for a Safe Return to Sport after ACLR? An Investigation of Physical Readiness and Integrated Movement Efficiency (PRIME).

BackgroundElite female athletes who successfully return to sport after anterior cruciate ligament reconstruction (ACLR) represent a high-risk group for secondary injury. Little is known about how the functional profile of these athletes compares to their teammates who have not sustained ACL injuries.PurposeTo compare elite collegiate female athletes who were able to successfully return to sport for at least one season following ACLR to their teammates with no history of ACLR with regard to self-reported knee function, kinetics, and kinematics during a double limb jump-landing task.Study DesignCross-Sectional StudyLevel of EvidenceLevel 3MethodsEighty-two female collegiate athletes (17 ACLR, 65 control) completed the knee-specific SANE (single assessment numeric evaluation) and three trials of a jump-landing task prior to their competitive season. vGRF data on each limb and the LESS (Landing Error Scoring System) score were collected from the jump-landing task. Knee-SANE, vGRF data, and LESS scores were compared between groups. All athletes were monitored for the duration of their competitive season for ACL injuries.ResultsAthletes after ACLR reported worse knee-specific function. Based on vGRF data, they unloaded their involved limb during the impact phase of the landing, and they were more asymmetrical between limbs during the propulsion phase as compared to the control group. The ACLR group, however, had lower LESS scores, indicative of better movement quality. No athletes in either group sustained ACL injuries during the following season.ConclusionDespite reporting worse knee function and demonstrating worse kinetics, the ACLR group demonstrated better movement quality relative to their uninjured teammates. This functional profile may correspond to short-term successful outcomes following ACLR, given that no athletes sustained ACL injuries in the competition season following assessment.

Examining the Relationship Between a Neuromuscular Control Baseline Battery for Sport-Related Concussion and Anterior Cruciate Ligament Injury Risk

To examine the relationship between the m-CTSIB and Landing Error Scoring System in a sample of collegiate female athletes. Recent literature has linked concussion and neuromuscular deficits in the lower extremity after injury. Neuromuscular control is frequently assessed using balance measures for concussion, but also dynamically to identify anterior cruciate ligament injury (ACL) risk via jump-landing movement screening. Thirty-nine healthy, collegiate female soccer (n = 22) and volleyball (n = 17) athletes completed the modified-Clinical Test of Sensory Interaction of Balance (m-CTSIB) and the Landing Error Scoring System (LESS). Measures consisted of total m-CTSIB sway index scores on individual conditions (firm surface eyes open [condition 1] and eyes closed [2], foam surface eyes open [3] and eyes closed [4]), m-CTSIB overall score, and total LESS errors. LESS scores were also categorized into a low (0-4 errors) and high (5 + errors) risk to determine if athletes with worse neuromuscular control on the LESS has worse balance on the m-CTSIB. A Spearman's rank-order correlation was conducted to determine the strength of the relationship between LESS and m-CTSIB performance. A series of Mann-Whitney U test were performed to determine differences between low and high LESS performance on m-CTSIB performance. There was a weak, negative correlation between LESS and m-CTSIB performance (rs(37) = -0.153, p = 0.35). Further, there were no differences between the low and high risk LESS groups on sway index scores on conditions 1 (U = 158.5, p = 0.39), 2 (U = 156.0, p = 0.36), 3 (U = 165.5, p = 0.51), or 4 (U = 128.5, p = 0.08), as well as overall m-CTSIB scores (U = 150.5, p = 0.28). There appears to be a lack of relationship between the LESS and m-CTSIB tests, revealing the independence of static and dynamic lower extremity neuromuscular function. Athletes who may be more at risk for ACL injury due to abnormal jump-landing biomechanics, do not differ from low-risk athletes on baseline balance assessment.

The Relationship between Landing Error Scoring System Performance and Injury in Female Collegiate Athletes.

BackgroundThe Landing Error Scoring System (LESS) is a standardized tool used to identify aberrant biomechanical movement patterns during a jump-landing task. Prior authors have examined the value of the LESS in identifying ACL injury risk in athletic populations. Yet, no study has evaluated the association between LESS performance and incidence of any type of lower extremity injury in female collegiate athletes across multiple sports.PurposeThe purpose of this study was to examine the association between LESS performance as measured with a markerless motion-capture system and lower extremity injury in female collegiate athletes.Study DesignProspective cohort study.MethodsOne hundred and ten DI female collegiate athletes (basketball, n=12; field hockey, n=17; gymnastics, n=14; lacrosse, n=27; softball, n=23; volleyball, n=17) completed a jump-landing test prior to the start of their sport seasons. The LESS was automatically scored using a Microsoft Kinect sensor and Athletic Movement Assessment software (PhysiMax®). Participants were tracked throughout one competitive season for incidence of time-loss lower extremity injury. A Receiver Operating Characteristic curve determined the optimal cutpoint for the total LESS score for predicting injury. Pearson’s Chi squared statistics examined the association between injury and LESS total scores >5. The Fisher exact test evaluated group differences for the frequency of receiving an error on individual LESS test items.ResultsFemale collegiate athletes with LESS scores >5 were not more likely to be injured than those with scores ≤5 (χ2=2.53, p=0.111). The relative risk of injury to this group was 1.78 (95% CI=0.86, 3.68) while the odds ratio was 2.10 (95% CI=0.83, 5.27). The uninjured group was more likely to receive an error on lateral trunk flexion at initial contact than the injured group (p=0.023).ConclusionThe LESS total score was not associated with an increased odds of lower extremity injury in this cohort of female collegiate athletes. Future studies to examine the association between individual LESS item scores and injury are warranted.Level of Evidence1b.

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

Sex-based differences in neuromuscular characteristics relevant to anterior cruciate ligament (ACL) injury risk may arise as compensation for divergent strength development during puberty. Strength training during this period may prevent the development of these undesirable neuromuscular characteristics. Strength-trained middle school girls will have improved jump-landing biomechanics compared with control participants. Cohort study. Level 3. Maximum voluntary isometric contraction in hip extension and abduction and knee extension and flexion as well as Landing Error Scoring System (LESS) scores were collected for healthy female middle school students of grades 6 to 8. Strength-training participants (STR: N = 30; height, 1.63 ± 0.07 m; mass, 48.1 ± 7.6 kg; age, 12.5 ± 1.0 y) were matched with control participants (CON: N = 30; height, 1.60 ± 0.09 m; mass, 47.2 ± 8.9 kg; age, 12.6 ± 0.9 y). The training consisted of a 6-month strength-training program administered through a gym class curriculum that targeted the lower extremity. A repeated-measures mixed-model analysis of variance was used for comparisons between groups and across time (α = 0.05). Stepwise linear regression was used to examine the relationship between strength change and LESS score change. Strength values (N·m/kg) increased across time and to a greater degree in STR for hip extension (baseline 3.98 ± 1.15 vs follow-up 4.77 ± 1.80), hip abduction (4.22 ± 1.09 vs 5.13 ± 2.55), and knee flexion (3.27 ± 0.62 vs 3.64 ± 1.40) compared with CON. LESS grades significantly decreased across time in STR (5.58 ± 1.21 vs 4.86 ± 1.44) and were significantly lower than CON (5.98 ± 1.42) at follow-up (P < 0.001). The change in hip extension and knee extension strength explained 67% of the variance (P < 0.001) in the LESS change score in the STR group. A school-based strength-training program that focused on hip and knee musculature significantly improved jump-landing biomechanics (as determined by LESS) relevant to ACL injury risk. Further investigation using different strength-training approaches in this age group is warranted. Strength training during adolescence holds promise as an injury prevention program. The use of a school-based approach is novel and may represent a robust opportunity for injury prevention programs, as physical education class is often mandatory in this age group.

The Landing Error Scoring System (LESS) and Lower Limb Power Profiles in Elite Rugby Union Players.

BackgroundThe Landing Error Scoring System (LESS) is a clinical test that assesses landing biomechanics during a drop-jump task. Performance measures such as jump height, power, contact time and reactive strength index are used commonly in athletic populations. Comparing results from the LESS against these performance measures has not been reported in elite rugby union.PurposeTo report i.) normative LESS scores for elite rugby union players ii.) correlations between LESS scores and performance measures and iii.) differences in performance measures between LESS scoring groups. A secondary purpose was to report the intra- and inter-rater reliability of the LESS test when used in elite rugby union players. # Study DesignCross-sectional design.MethodsThirty-six male, elite rugby union players participated. Each participant completed three trials of the LESS and performance measures were recorded concurrently using the OptojumpTM. LESS trials were scored independently by the authors. Statistical analyses were used to confirm reliability, data normality, and between group differences (p<0.05).ResultsThe LESS test is a reliable testing tool in elite rugby union players (excellent intra- (ICC=0.96) and inter-rater (ICC=0.94) reliability). One player demonstrated an excellent LESS score, six players had good scores, eight players moderate scores and the majority of the group, 21 players, scored poorly. LESS scores were correlated to contact time (r = -0.461, p = 0.005) only. Participants with moderate to poor LESS scores (a score ≤5) produced greater power (p=0.036, η2 = 0.139), contact time (p=0.002, η2 = 0.268) and reactive strength index (p=0.016, η2 = 0.180). There were no differences in jump height (p=0.842) between players scoring excellent to good and moderate to poor.ConclusionThe results of the current study demonstrate excellent intra- and inter-rater reliability for the LESS, supporting its use as a clinical assessment tool in elite rugby union players. The majority of players presented with moderate to poor LESS scores, indicating an area of concern in this population. Participants scoring moderate to poor in the LESS recorded significantly higher power and reactive strength index, increased contact time but not jump height. This suggests participants with high-risk landing biomechanics may also produce higher performance measures, but these do not necessarily result in an improved jump height.

Clinical Implications of Landing Distance on Landing Error Scoring System Scores.

The Landing Error Scoring System (LESS) screens for risk of noncontact anterior cruciate ligament injury. The LESS requires individuals to jump forward from a 30-cm box to a distance of 50% of their body height. However, different landing distances have been cited in the scientific literature. To examine whether landing distance influences LESS outcomes. Cross-sectional study. Laboratory. Seventy young active individuals (34 males, 36 females). Participants performed 3 × 30-cm jump-landing tasks under 2 landing conditions in randomized order: (1) 50% of body height (d50%), (2) self-selected distance (dss). Mean LESS scores, proportions of individuals categorized at high (LESS: ≥ 5 errors) and low (LESS: < 5 errors) injury risk, and landing distances were compared between conditions using generalized estimating equations. Consistency of risk categorization was examined using odds ratios (ORs) and McNemar tests. McNemar and Wilcoxon signed rank tests were used to compare the occurrence of specific LESS errors. Participants landed closer to the box under the dss condition (difference = -23.28 [95% CI = -20.73, -25.81]%, P < .001). Group mean LESS scores (difference = -0.01 [95% CI = -0.59, 0.57] error, P = .969) and risk categorization (OR = 0.94 [95% CI = 0.47, 1.88], P = .859) were similar between conditions. However, individual-level risk categorization was inconsistent in 33% of participants, as was the occurrence of specific errors. Using dss during the LESS might lead to different LESS errors and risk categorizations at an individual level than using d50%. Given that individual LESS scores are of primary interest in clinical and sport settings and the injury-risk threshold has not been validated for dss, we recommend use of the original LESS protocol. When only group mean LESS scores or proportions of at-risk individuals are of interest, using dss is feasible to facilitate the testing of large cohorts.