Effects of Whole Body Vibration on Quadriceps Function, Landing Biomechanics, and Performance in Individuals With ACL Reconstruction

Individuals who undergo anterior cruciate ligament reconstruction (ACLR) are at heightened risk of secondary anterior cruciate ligament (ACL) injury (e.g. additional injury to the ACL in either knee). One of the primary physiological consequences of ACLR is the presence of quadriceps dysfunction (i.e. reduced activation and strength) which has been linked to altered gait and landing biomechanics. Aberrant landing biomechanics have been associated with an increased risk of both primary and secondary ACL injury, thus additional research is needed to evaluate the efficacy of treatments aimed to reduce quadriceps dysfunction and restore adequate landing biomechanics in attempts to reduce secondary ACL injury. Whole-body Vibration (WBV) has demonstrated success in improving quadriceps function and gait biomechanics in individuals with ACLR, however its effectiveness on landing biomechanics is unknown. To evaluate the acute effects of WBV on landing biomechanics in those with ACLR, a non-randomized crossover-controlled trial was conducted to determine if a single bout of WBV improved landing biomechanics greater than a control condition. Participants completed two separate testing sessions (separated by at least one week) in which measures of quadriceps function and landing biomechanics were assessed before and after either a control (no WBV) or WBV intervention. Separate linear mixed-effects models of post-test values for each dependent outcome were conducted with condition (control vs WBV) and limb (ACLR vs Uninvolved) as an interaction term, and each condition pre-test values and time post-ACLR as fixed effect covariates and a random effect of subject. The investigators expect to observe a significant improvement in landing biomechanics following WBV compared to the control condition.