The muscles that move the thigh originate on the pelvic girdle and lumbar vertebrae and insert into the femur and tibia. The iliopsoas muscle is an important hip flexor that is a combination of the psoas major and iliacus muscles. There are three gluteal muscles. The largest, the gluteus maximus, extends the femur and rotates it laterally at the hip joint. The gluteus medius and gluteus minimus lie beneath the gluteus maximus and function as femoral abductors and medial rotators. The gluteus maximus and tensor fascia latae insert on a thick band of connective tissue, called the iliotibial tract or the IT band, stabilizing the hip and knee joints. The piriformis , obturator internus , obturator externus , superior gemellus, inferior gemellus, and quadratus femoris muscles lie deep in the gluteus maximus and can laterally rotate the femur. The adductor longus, adductor brevis, adductor magnus, and pectineus muscles are located medially on the thigh and contribute to thigh adduction and medial and lateral rotation. Usually, a pulled groin is an injury to one of these muscles.