What is the Semimembranosus?
The semimembranosus is one of the three hamstring muscles on the back of your thigh. It sits on the inner side of the hamstrings, running from the bottom of your pelvis down to the upper part of your shin bone near the knee. You can think of it as a strong strap that helps you bend your knee and extend your hip, meaning it helps pull your leg backward behind you. It also helps stabilize the knee, especially when you change direction, decelerate, or hinge at the hips.