Which muscles form the hamstrings?

• A. Rectus Femoris
• B. Hamstrings: Semitendinosus, Semimembranosus, Biceps Femoris
• C. Gastrocnemius
• D. Latissimus Dorsi

Answer: (B)

The hamstrings are a group of muscles on the back of the thigh that work together to bend the knee and help straighten the hip. They consist of semitendinosus, semimembranosus, and the biceps femoris. The biceps femoris has two heads (long and short); the long head crosses both the hip and knee, while the short head crosses only the knee. This trio forms the hamstrings, setting them apart from muscles in other regions. By contrast, the rectus femoris is part of the quadriceps on the front thigh and extends the knee while flexing the hip; the gastrocnemius lies in the calf and assists with plantarflexion (and can aid knee flexion), and the latissimus dorsi is a large back muscle with no role in the hamstrings.