The Landing Error Scoring System (LESS) Is a Valid and Reliable Clinical Assessment Tool of Jump-Landing Biomechanics

Context: Return to activity in the presence of quadriceps dysfunction may predispose individuals with anterior cruciate ligament reconstruction (ACLR) to long-term joint degeneration. Asymmetry may manifest during movement and result in altered knee-joint-loading patterns; however, the underlying neurophysiologic mechanisms remain unclear.Objective: To compare limb symmetry of quadriceps neuromuscular function between participants with ACLR and participants serving as healthy controls.Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: A total of 22 individuals with ACLR (12 men, 10 women) and 24 individuals serving as healthy controls (12 men, 12 women).Main Outcome Measure(s): Normalized knee-extension maximal voluntary isometric contraction (MVIC) torque (Nm/ kg), quadriceps central activation ratio (CAR) (%), quadriceps motor-neuron-pool excitability (Hoffmann reflex to motor wave ratio), and quadriceps active motor threshold (AMT) (% 2.0 T) were measured bilaterally and used to calculate limb symmetry indices for comparison between groups. We used analyses of variance to compare quadriceps Hoffmann reflex to motor wave ratio, normalized knee-extension MVIC torque, quadriceps CAR, and quadriceps AMT between groups and limbs.Results: The ACLR group exhibited greater asymmetry in knee-extension MVIC torque (ACLR group ¼ 0.85 6 0.21, healthy group ¼ 0.97 6 0.14; t 44 ¼ 2.26, P ¼ .03), quadriceps CAR (ACLR group ¼ 0.94 6 0.11, healthy group ¼ 1.00 6 0.08; t 44 ¼ 2.22, P ¼ .04), and quadriceps AMT (ACLR group ¼ 1.13 6 0.18, healthy group ¼ 1.02 6 0.11; t 34 ¼À2.46, P ¼ .04) than the healthy control group.Conclusions: Asymmetries in measures of quadriceps function and cortical excitability were present in patients with ACLR. Asymmetry in quadriceps strength, activation, and cortical excitability persisted in individuals with ACLR beyond return to recreational activity. Measuring the magnitude of asymmetry after ACLR represents an important step in understanding long-term reductions in self-reported function and increased rate of subsequent joint injury in otherwise healthy, active individuals after ACLR.Key Words: quadriceps activation, limb symmetry index, transcranial magnetic stimulation Key PointsThe anterior cruciate ligament reconstruction (ACLR) group exhibited a weaker, less activated quadriceps and less cortical excitability in the reconstructed limb than in the contralateral limb and in the limbs of the healthy control group. Asymmetry in quadriceps strength, activation, and cortical excitability persisted in individuals with ACLR beyond return to recreational activity. Chronic asymmetry indicated reduced dynamic force absorption at the knee and may explain the increased rate of knee reinjury and chronic joint degeneration after ACLR.

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“…25 This ratio is thought to represent the proportion of the total motor-neuron pool that can be recruited. 26 …”

Section: Quadriceps H-reflexmentioning

confidence: 99%

Persistent Neuromuscular and Corticomotor Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Kuenze

Hertel

Weltman

et al. 2015

Journal of Athletic Training

109

116

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“…Three-dimensional knee kinematics and kinetics, quantified using marker-based motion analysis systems, have been used to identify potential risk factors for ACL injuries [1,2]. Furthermore, knee kinematics and kinetics in vertical drop jumps are utilized for ACL injury risk assessment [2,3] and evaluation of training interventions [4,5].…”

Section: Introductionmentioning

confidence: 99%

Reliability of knee biomechanics during a vertical drop jump in elite female athletes

2016

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This file was downloaded from the institutional repository Brage NIH -brage.bibsys.no/nih Mok, K.-M., Petushek, E., Krosshaug, T. (2016 tron.krosshaug@nih.no Conflict of Interest:The authors declare that there are no conflicts of interest. Author's contribution:All authors have made substantial contributions to all of the following: (1) the conception and design of the study, or acquisition of data, or analysis and interpretation of data, (2) drafting the article or revising it critically for important intellectual content, (3) final approval of the version to be submitted. Acknowledgements:The Abstract (250 words)The purpose of the study was to assess the within-session and between-session reliability of knee kinematics and kinetics in a vertical drop jump task among elite female handball and football athletes. Specifically, we aimed to quantify the within-session waveform consistency and betweensession consistency of the subject ranking for a variety of knee kinematics and kinetics.Forty-one elite female handball and football (soccer) athletes were tested in two sessions. The reliability of three-dimensional knee biomechanical measurements was quantified by the intraclass correlation, Spearman's rank correlation, and typical error. All the selected discrete variables achieved excellent within-session reliability (ICC > 0.87). The typical error of valgus angles, internal rotation angles, and internal rotation moment was constant throughout the whole stance phase. For between-session reliability, the selected discrete variables achieved good to excellent reliability (ICC > 0.69), except peak internal rotation moment (ICC = 0.40). All between-session rank correlation coefficients ranged from 0.56 to 0.90. Most of the discrete variables achieved good to excellent reliability in both within-session and between-session analysis. Moreover, moderate to strong between-session consistency of subject rankings was found, implying that the measurements assessed during the vertical drop jump demonstrate sufficient reliability to be used in both single-session and multiple-session studies.2

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“…In the present study, the subjects 80 landed with a toe angle of 8.9 ± 6.4° (range -2.7º to 20.3º). Thus, no one met the criterion 81 of the Landing Error Scoring System (LESS) that used a toe angle cutoff of >30° for 82 either toe-in or toe-out [18]. The toe-in and toe-out landing tasks were recorded randomly 83 following the natural landing task after the subjects felt familiar with the tasks following 84 several practices.…”

mentioning

confidence: 99%

The effect of changing toe direction on knee kinematics during drop vertical jump: a possible risk factor for anterior cruciate ligament injury

Ishida

Yamanaka

Takeda

et al. 2013

Knee Surg Sports Traumatol Arthrosc

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(natural, toe-in, toe-out). The knee kinetics and kinematics during landing were evaluated 5 using a motion analysis system. Results under three toe conditions were compared using 6 a one-way repeated-measures analysis of variance and a post-hoc Bonferroni test. Results: Toe-in landing was associated with a significantly greater knee abduction angle, 8 tibial internal rotation angle, and knee abduction moment than the natural and toe-out 9 conditions. Toe-out landing was associated with significantly greater tibial internal 10 rotational angular velocity.

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The Landing Error Scoring System (LESS) Is a Valid and Reliable Clinical Assessment Tool of Jump-Landing Biomechanics

Abstract: The LESS is a valid and reliable tool for identifying potentially high-risk movement patterns during a jump-landing task.

Cited by 519 publications

References 37 publications

Persistent Neuromuscular and Corticomotor Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Persistent Neuromuscular and Corticomotor Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

Reliability of knee biomechanics during a vertical drop jump in elite female athletes

The effect of changing toe direction on knee kinematics during drop vertical jump: a possible risk factor for anterior cruciate ligament injury

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