Effects of localized muscle vibration on dynamic stability related to anterior cruciate ligament injury (2023)
Undergraduate: Patrick Smith
Faculty Advisor: Troy Blackburn
Department: Exercise and Sport Science
Anterior cruciate ligament reconstruction (ACLR) utilizing hamstring tendon (HT) autografts leads to hamstrings dysfunction (e.g. deficits in strength and activation) and impaired dynamic knee stabilization that increase the risk of secondary ACL injury. Time to stabilization (TTS) and dynamic postural sway index (DPSI) identify deficits in dynamic postural control during single-leg landing tasks in individuals with ACLR and may be related to secondary ACL injury risk. Local muscle vibration (LMV) produces improvements in quadriceps neuromuscular function among ACLR individuals and improves postural control in healthy individuals. LMV applied to the hamstrings might also result in improved neuromuscular function of the hamstrings, improving dynamic postural stability. The purpose of this study was to determine the influence of LMV applied to hamstrings on TTS and DPSI among healthy controls. In this crossover study, subjects performed a single-leg landing task onto a force plate from which TTS and DPSI were assessed before and after a control or LMV intervention. Statistical analysis revealed no significant effects of LMV on the indices of dynamic postural control. Previous literature suggests that vibration improves postural stability in individuals with ACLR who inherently possess deficits in sensorimotor function, however these deficits are not present in healthy controls. Because healthy controls do not display these same sensory deficits and muscle dysfunction, future studies should investigate the effects of LMV among ACLR individuals.
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