Pelvis Gluteal & Hip Anatomy Quiz

The gluteal muscle group consists of muscles located in the buttock region that act on the hip joint. Gluteus Maximus is the largest and most superficial of this group and is responsible for hip extension and external rotation. Trapezius acts on the shoulder, Soleus on the ankle, and Rectus Femoris on the knee and hip, excluding them from the gluteal group.

The gluteus medius plays a critical role in hip abduction and stabilization of the pelvis during single-leg stance, such as walking. It prevents pelvic drop on the opposite side. While it assists with rotation and flexion, its most clinically important function is maintaining pelvic alignment, making hip abduction and stabilization the correct focus.

The Tensor Fascia Latae is innervated by the Superior Gluteal Nerve, which also innervates the gluteus medius and minimus. This nerve arises from spinal segments L4 to S1. The Inferior Gluteal Nerve innervates only the gluteus maximus, while femoral and obturator nerves supply anterior and medial thigh muscles.

The Inferior Gluteal Nerve exclusively innervates the Gluteus Maximus. This muscle is the primary hip extensor and contributes to external rotation. All other gluteal muscles receive innervation from the Superior Gluteal Nerve, making Gluteus Maximus the only correct answer for inferior gluteal nerve supply.

The deep hip rotators are innervated by branches of the lumbosacral plexus. These include piriformis, obturator internus, gemelli, and quadratus femoris. Quadriceps, hamstrings, and adductors receive innervation from different nerve groups, making deep hip rotators the only anatomically accurate choice.

The Obturator Externus is uniquely innervated by the Obturator Nerve, unlike most deep hip rotators, which receive branches from the sacral plexus. This distinction is important in clinical anatomy, as obturator nerve injuries affect hip external rotation through obturator externus involvement.

Piriformis and Obturator Internus both receive innervation predominantly from spinal segment S1. Their shared spinal level reflects similar anatomical positioning and function in lateral rotation and hip stabilization. Other options either involve different spinal levels or muscles that do not share identical innervation patterns.

The Psoas Major is innervated directly by branches of the Lumbar Plexus, primarily L1 to L3. It is a major hip flexor and anterior pelvic muscle. The other options are either abdominal, gluteal, or thigh muscles with different nerve supplies, making Psoas Major the correct choice.

The Iliacus muscle is innervated by the Femoral Nerve and works with the Psoas Major to flex the hip. Although Rectus Femoris also uses the femoral nerve, it belongs to the quadriceps group. Pectineus has mixed innervation, and Psoas Major is supplied by lumbar plexus branches.

Obturator Externus does not attach to the greater trochanter. Instead, it inserts into the trochanteric fossa of the femur. Other listed muscles attach directly or indirectly to the greater trochanter, making Obturator Externus the only anatomically correct answer.