1. Investigating the Link Between Kinematic, Kinetic and Muscular Symmetry in Young Adults 12 or More Months post-ACL Reconstruction

Abstract

Anterior cruciate ligament (ACL) injury after primary reconstruction and return-to-sport clearance is common. Since research indicates asymmetry as a valid predictor of injury, it is proposed that inter-limb asymmetry following ACL reconstruction contributes to the elevated incidence of re-injury in this population. Current return-to-sport protocol include objective tests such as joint laxity and strength tests, as well as single leg hop and drop landing tests. Since these assessments are based on visual observation, or simple kinematics measurements, it is unclear how visual asymmetry reflects the underlying joint forces and muscular effort responsible for the performance in these tasks. This study aims to assess the asymmetry present at the kinematic, kinetic, and motor control levels to clarify the after-effects of ACL reconstruction. This pilot study will help us appreciate if additional work exploring screening measures as effective tools for predicting ACL injury following primary reconstruction is warranted. Standard techniques will be used to measure the kinematics, joint kinetics and muscle activation during this 25-repetition squat protocol. Correlations will compare the left and right lower limbs for joint angular displacement, joint angular velocity, joint power, vertical ground reaction forces, and muscle activation amplitude.