Context: Muscle vibration enhances neuromuscular function, but the mechanism of improvement is unclear. Heightened motor neuron excitability within the spinal cord could be responsible for improved muscle function following vibration. However, the response of supraspinal structures - such as the motor cortex - to vibration is unclear. Vibratory treatments could benefit individuals with quadriceps dysfunction, such as patients with knee pathologies. Whole body (WBV) and local muscle vibration (LMV) improve quadriceps function but the efficacy of treatment may vary. Objective: To compare the effects of whole body and local muscle vibration on measures of quadriceps function. Participants: Sixty recreationally active young adults, and twenty individuals with anterior cruciate ligament reconstruction. Interventions: Healthy subjects were randomized to one of three groups (WBV, LMV and control) and completed three testing sessions. Subjects completed testing of quadriceps spinal neuron excitability, corticomotor excitability, or a maximal voluntary isometric contraction and then completed an intervention based on group assignment. Subjects repeated the assessment immediately, ten minutes, and twenty minutes following the intervention. Subjects completed the remaining two assessments in separate sessions. Injured subjects completed testing of quadriceps spinal neuron excitability, corticomotor excitability, and maximal voluntary isometric contraction, and then complete one of three treatment conditions (WBV, LMV, control). Subjects completed follow up testing following the intervention. Subjects completed the remaining two treatment conditions in separate visits. Main Outcome Measures: Quadriceps peak torque (PT), rate of torque development (RTD), electromyography (EMG), central activation ratio (CAR), active motor threshold (AMT), motor evoked potential (MEP) amplitude, and Hoffman Reflex. Results: Healthy subjects in the WBV group improved in quadriceps PT, EMG, CAR, AMT and MEP amplitude. Healthy subjects in the LMV group improved in quadriceps EMG and AMT. Injured subjects improved in quadriceps PT, EMG, CAR, and AMT in the WBV and LMV conditions. Conclusions: WBV and LMV improve quadriceps function and could be a useful tool to improve the efficacy of strengthening protocols in patients with knee pathologies. Improvements in quadriceps function resulting from WBV and LMV can be attributed to greater corticomotor excitability. WBV may be more suitable to improve quadriceps function in healthy individuals compared to LMV.