Effect of a pelvic wedge and belt on the medial and lateral hamstring muscles during knee flexion

[Purpose] This study developed a pelvic wedge and belt and investigated their effects on the selective activation of medial and lateral hamstring muscles during knee flexion. [Subjects and Methods] Nine adults were enrolled. The participants performed exercises without and with the pelvic wedge and belt, and the electromyographic activities of the medial and lateral hamstring muscles were recorded. [Results] The activity of the medial hamstring was increased significantly when using the pelvic wedge and belt, while the activity of the lateral hamstring did not differ significantly. [Conclusion] The pelvic wedge and belt provide a self-locked position during knee flexion in the prone position. Prone knee flexion in this position is an effective self-exercise for balanced strengthening of the medial hamstring.