Which muscle elevates the hip on the opposite side when acting unilaterally?

• A. Psoas major
• B. Gluteus medius
• C. Latissimus dorsi
• D. Quadratus lumborum

Answer: (D)

Hip hiking, lifting the iliac crest on one side, is produced most effectively by a muscle that acts on the pelvis in the frontal plane when it contracts on one side. The quadratus lumborum does exactly this: when it contracts unilaterally, it elevates the iliac crest on that same side, raising the corresponding hip. This makes it the best choice for a unilateral hip elevation action.

Psoas major mainly flexes the hip, so it doesn’t elevate the pelvis. Gluteus medius acts to abduct the thigh and stabilize the pelvis, helping keep it level during single-leg stance rather than lifting it. Latissimus dorsi is a large back muscle involved in trunk and arm movements and does not contribute to elevating the pelvis.

So, the unilateral action that elevates the hip is best attributed to quadratus lumborum.