Hamstrings:A group of three muscles, including the semitendinosus, at the back of the thigh responsible for bending the knee and extending the hip.
Knee Flexion: The act of bending the knee by decreasing the angle between the thigh and lower leg, a movement largely facilitated by muscles like the semitendinosus.
Hip Extension: A movement involving an increase in angle between the front of the pelvis and thighs, powered by muscles including the semitendinosus