Baker's cysts arise between the tendons of the medial head of the gastrocnemius and the semimembranosus muscles.
Additionally, the following thigh muscles extend the hip: semimembranosus, semitendinosus, and long head of biceps femoris.
Posterior compartment muscles of the thigh are the hamstring muscles, which include semimembranosus, semitendinosus, and biceps femoris.
The hamstring muscle group is made up of the biceps femoris, semitendinosis and semimembranosus.
The semimembranosus is named for the flat shape of its superior attachment.
However, because the semimembranosus is wider and flatter than the semitendinosus, it is still possible to palpate the semimembranosus directly.
This attachment is exposed by making a small incision parallel to the fibers along the posterior edge of the anterior arm of the semimembranosus tendon.
Functionally, the semimembranosus is similar to the semitendinosus, and thus produces extension at the hip joint and flexion and medial rotation at the knee.
