Which action does the gluteus maximus primarily perform?

Which action does the gluteus maximus primarily perform?

• A. Hip adduction
• B. Thigh extension
• C. Knee flexion
• D. Internal rotation

Answer: (B)

Hip extension is the primary action of the gluteus maximus. This large muscle runs from the posterior ilium and sacrum to the gluteal tuberosity of the femur and the iliotibial tract, so when it contracts it pulls the femur backward, straightening the hip joint. This makes it the main mover when moving from a flexed thigh position to standing, climbing stairs, and propelling the body forward during running or jumping. It can also help rotate the thigh outward when the hip is extended, but it is not the primary mover for knee movement and it does not mainly adduct the thigh.

Hip extension is the primary action of the gluteus maximus. This large muscle runs from the posterior ilium and sacrum to the gluteal tuberosity of the femur and the iliotibial tract, so when it contracts it pulls the femur backward, straightening the hip joint. This makes it the main mover when moving from a flexed thigh position to standing, climbing stairs, and propelling the body forward during running or jumping. It can also help rotate the thigh outward when the hip is extended, but it is not the primary mover for knee movement and it does not mainly adduct the thigh.