Origin
Ischial tuberosity
Insertion
Medial surface of shaft of tibia
Actions
Flexes and slightly medially rotates leg; after flexion, extends thigh
Nerve
Tibial portion of sciatic nerve (L5, S1, S2)
Note
During walking or running, the hamstrings are used to slow down the leg at the end of its swing and prevent the trunk from flexing at the hip. They are susceptible to being strained by resisting the momentum of these body parts.