What do the hamstrings do?

• A. Knee extension
• B. Plantarflex the foot
• C. Knee flexion and hip extension
• D. Hip abduction

Answer: (C)

The hamstrings are two‑joint muscles that cross both the hip and the knee, so they influence actions at both joints. When they contract, they bend the knee (knee flexion) and help move the thigh backward at the hip (hip extension). That combination—knee bending and hip extension—best captures what the hamstrings do.

Plantarflexion of the foot is done by the calf muscles crossing the ankle, not the hamstrings. Hip abduction is performed mainly by the gluteal muscles on the outer hip. Knee extension is the primary action of the quadriceps.