ACUTE EFFECTS OF LOCAL MUSCLE VIBRATION ON HAMSTRING MUSCLE FUNCTION FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING HAMSTRING TENDON AUTOGRAFTS

Anterior cruciate ligament (ACL) injuries are common and secondary injury risk remains after rehabilitation influenced by strength imbalances and poor landing biomechanics, especially after ACL reconstruction (ACLR) with hamstring tendon autografts (HT). The hamstrings maintain knee joint stability as dynamic stabilizers protecting the ACL. Local muscle vibration (LMV) demonstrates increased quadriceps function after ACLR, but insufficient evidence exists on hamstring function. The purpose of this thesis is to determine the acute effects of LMV on hamstring function following HT ACLR. Thirteen participants completed two session assessing hamstring peak torque (PT) and rate of torque development (RTD) during maximal voluntary isometric contractions before and after LMV or control (no vibration) intervention. No significant difference in PT or RTD between intervention pre-/post-test or when controlling for time since ACLR. A single session of LMV may not increase hamstring function in individuals following HT ACLR, indicating further research is necessary to determine effectiveness.