Which group is listed as the hip external rotators during gait?

Which group is listed as the hip external rotators during gait?

• A. Iliopsoas, rectus femoris, sartorius
• B. Tensor fascia lata, gluteus minimus, anterior gluteus medius
• C. Tibialis anterior, EHL, EDL
• D. Six short external rotators, posterior fibers of gluteus medius, gluteus maximus

Answer: (D)

External rotation of the hip during gait is produced by the deep set of hip rotators that surround the joint, plus contributions from the gluteal muscles when the thigh is in extension. The six short external rotators—piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris—are specifically arranged to laterally rotate the femur and to help stabilize the femoral head in the acetabulum as the leg bears weight. In addition, the posterior fibers of the gluteus medius and the gluteus maximus contribute to external rotation, especially when the hip is extended, such as during late stance and pre-swing, helping to position the leg for push-off. The other muscles listed don’t serve primarily as external rotators during gait. The iliopsoas, rectus femoris, and sartorius are mainly hip flexors (with sartorius having multiple actions but not as primary external rotators in gait). The tensor fascia latae and the anterior fibers of the gluteus medius/minimus act as abductors and internal rotators rather than external rotators. The muscles of the lower leg shown (tibialis anterior, extensor hallucis longus, extensor digitorum longus) affect the foot and ankle, not the hip.

External rotation of the hip during gait is produced by the deep set of hip rotators that surround the joint, plus contributions from the gluteal muscles when the thigh is in extension. The six short external rotators—piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris—are specifically arranged to laterally rotate the femur and to help stabilize the femoral head in the acetabulum as the leg bears weight. In addition, the posterior fibers of the gluteus medius and the gluteus maximus contribute to external rotation, especially when the hip is extended, such as during late stance and pre-swing, helping to position the leg for push-off.

The other muscles listed don’t serve primarily as external rotators during gait. The iliopsoas, rectus femoris, and sartorius are mainly hip flexors (with sartorius having multiple actions but not as primary external rotators in gait). The tensor fascia latae and the anterior fibers of the gluteus medius/minimus act as abductors and internal rotators rather than external rotators. The muscles of the lower leg shown (tibialis anterior, extensor hallucis longus, extensor digitorum longus) affect the foot and ankle, not the hip.