The pectineus is a flat, quadrangular muscle located in the upper inner thigh. It plays a crucial role in hip movement, primarily assisting with hip flexion and adduction. This muscle is part of the adductor group and is situated just below the iliopsoas muscle. Originating from the pectineal line of the pubis, the pectineus inserts into the femur at the pectineal line. It is innervated by the femoral nerve and sometimes receives additional innervation from the obturator nerve. Strengthening this muscle can enhance overall hip stability and mobility.