Assessing Symmetry in Landing Mechanics During Single-Leg and Bilateral Tasks in Healthy Recreational Athletes

INTRODUCTION: ACL-reconstructed (ACL-R) patients exhibit side-to-side asymmetries in movement and loading patterns after surgery, some of which are predictive of a secondary ACL injury. These asymmetries have not been fully assessed in healthy athletes. PURPOSE: To quantify side-to-side symmetry in secondary injury predictors in healthy athletes and compare these metrics to those measured in previous cohorts of ACL-R patients, as well as to assess differences in these metrics between two landing tasks and between sexes. METHODS: 60 healthy recreational athletes performed seven trials of a stop-jump task and seven trials of a single-leg hop for distance on each limb. The kinematics and kinetics of the first landing of the stop-jump and the landing of the single-leg hop were analyzed with a 10-camera motion analysis system (240Hz) and 2 embedded force plates (1920Hz). Limb symmetry indices (LSIs) were calculated for each variable and compared between subject groups, tasks, and sexes with Wilcoxon Signed Rank tests (p<0.05). RESULTS: Control subjects exhibited asymmetry in hop distance (p=0.006). ACL-R subjects displayed greater asymmetry in knee flexion variables, peak forces, and peak knee extension moments during the bilateral landing (p<0.001) and in hop distance (p<0.001). Control subjects showed greater asymmetry in knee flexion variables during the single-leg hop (p<0.001). Males and females showed similar symmetry in both tasks. CONCLUSIONS: Symmetry cannot be assumed in control subjects in all metrics. Asymmetries are more prevalent in ACL-R athletes than in healthy controls. Future work will continue to examine the usefulness of each metric in assessing ACL-R rehabilitation.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biomedical Engineering

Department dc:contributor.department

Biomedical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2017

Author dc:creator

• McConnell, Evan Paul

Chair dc:contributor.committeechair

• Queen, Robin M.

Committee members dc:contributor.committeemember

• Brolinson, P. Gunnar
• Williams, Dorsey S.

• ACL
• Biomechanics
• Landing
• Symmetry
• Kinematics
• Kinetics
• Motion Capture
• Athletes
• Sports

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:10897

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/78348