Quadratus Femoris Muscle

Description

Posterior to the left hip joint, the quadratus femoris appears as a short, rectangular muscle spanning from the lateral border of the ischial tuberosity to the quadrate tubercle on the intertrochanteric crest of the proximal femur. Superior to it lie the obturator internus tendon and the paired gemelli, while the gluteus maximus layer is removed to expose the deep external rotators. Medial to the muscle sits the ischium, and laterally the structure tucks against the posterior aspect of the femoral neck and greater trochanter region, with capsular elements and articular cartilage of the acetabulofemoral joint rendered for context. Orientation is clear. This is deep posterior hip anatomy. Quadratus femoris is a frequent pain generator in deep gluteal syndrome and a key landmark when teaching the short external rotators as a functional unit that stabilizes the femoral head during gait. Its intimate relationship to the medial circumflex femoral artery at the posterior proximal femur, and its proximity to the sciatic nerve as it courses inferior to piriformis, matter when discussing posterior hip approaches and the differential for buttock pain with external rotation weakness. The rectangular fiber direction also makes it a clean example for explaining external rotation and adduction moment arms compared with piriformis or obturator internus. Use this plate for gross anatomy lab atlases, orthopaedic and sports medicine teaching on posterior hip pain, and surgical education modules covering the Kocher-Langenbeck and other posterior exposures where the short external rotators define the dissection plane. It also fits radiology correlation in axial MRI of the deep gluteal space, where quadratus femoris edema can accompany ischiofemoral impingement. Anatomical accuracy verified by SciePro's Medical Advisory Board.