Which muscles are primarily involved in hip extension during a squat?

• A. Quadriceps only
• B. Gluteus maximus and hamstrings; adductor magnus may contribute.
• C. Abductors only
• D. Iliopsoas and rectus femoris

Answer: (B)

In a squat, the movement at the hip is driven mainly by muscles that extend the hip joint. The primary mover is the gluteus maximus, which contracts to pull the thigh backward and straighten the hip as you rise. The hamstrings also cross the hip and knee, so they assist with hip extension, especially when the knee is flexed during the squat. The adductor magnus can contribute as well, particularly its hamstring portion, which adds to hip extension when the knee is bent.

Other muscles aren’t the main actors here. The quadriceps are knee extensors, so they power the knee straightening rather than the hip, even though they cross the hip. The rectus femoris, while crossing both joints, acts mainly as a hip flexor, which would oppose hip extension. The iliopsoas and the hip abductors aren’t the primary drivers of hip extension, as their roles are more about flexion and stabilization in the frontal plane, respectively.

So, the combination of gluteus maximus and hamstrings does the heavy lifting for hip extension in a squat, with adductor magnus contributing if the knee is flexed.