Even though the muscles of the hip can be divided into five groups, they share a similar function of stabilizing the pelvis by acting on the thigh.
Iliopsoas: This muscle group contains the iliacus, psoas major, and psoas minor muscles. They originate from the posterior abdominal wall and attach to the lesser trochanter on the femur. This muscle group has a role in flexion and external rotation of the thigh.
Gluteals: There are superficial and deep gluteal muscles. The gluteus maximus, gluteus medius, gluteus minimus, and tensor fascia lata make up the superficial muscle group which enables extension and thigh movement away from the midline. The deep gluteal muscle group consists of the quadratus femoris, gemellus inferior, gemellus superior, piriformis, obturator internus, and obturator externus. This muscle group stabilizes the pelvis with external rotation of the thigh at the hip joint.
Adductors: There are six hip adductor muscles that form this muscle group: the pectineus, gracilis, adductor longus, adductor brevis, adductor magnus, and adductor minimus. These muscles originate from the pubis, travel over the hip joint, and attach to the femur. The adductor muscles facilitate thigh movement towards the midline of the body.
Rectus Femoris: This is one of the four quadriceps femoris muscles located on the anterior (front) thigh. It is a hip flexor muscle that originates at the ilium of the pelvis. This muscle flexes the thigh at the hip joint as well as leg extension at the knee joint.
Hamstrings: The semitendinosus, semimembranosus, and biceps femoris are the three biarticular muscles that form the hamstrings. These muscles originate at the bottom of the pelvis and travel down the posterior (back) thigh. This muscle group pulls the hip backward to aid in hip extension and also contributes to knee flexion.