1) Gluteus Maximus, 2) Gluteus Medius, 3) Gluteus Minimus, and 4) Tensor Fascia Lata. 
The gluteus medius muscle is the primary muscle(major abductor) responsible for the hip abduction, with the Gluteus Minimus assisting. The synergist muscles are the psoas, piriformis, Tensor Fascia Latae (TFL), quadratus lumborum and rectus femoris. The hip abductor muscles are responsible for lifting your thigh out to the side. They also stabilize your pelvis when you walk or stand on one leg. The primary hip abductors are the gluteus minimus and medius and the tensor fasciae latae. The sartorius and the piriformis are secondary hip abductors. HIP ABDUCTOR MUSCLES The hip abductor muscles are a group of four muscles located in the buttocks and lateral hip region on both sides of the body. Their names are: 1) Gluteus Maximus, 2) Gluteus Medius, 3) Gluteus Minimus, and 4) Tensor Fascia Lata. These muscles are shown in Figure 1 below: Figure 1. The gluteus medius muscle is the primary muscle(major abductor) responsible for the hip abduction, with the Gluteus Minimus assisting. The synergist muscles are the psoas, pir … iformis, Tensor Fascia Latae (TFL), quadratus lumborum and rectus femoris. Hip abduction is when the upper-leg bone, the femur, is moved out to the side and away from the body. Hip abduction exercises are important because they strengthen the muscles that stabilize the femur into the hip joint. To work the hip abductor muscles, perform the hip abduction exercises one to three times a week. The Hip Abductor Muscles. INNERVATION (NERVE SUPPLY) The nerve supply to the abductor muscles is as follows: The Gluteus Maximus is supplied by the Inferior Gluteal Nerve and branches from the Sacral Plexus. The Gluteus Medius, Gluteus Minimus, and Tensor Fascia Lata are supplied by the Superior Gluteal Nerve.
http://www.answers.com/Q/What_muscles_are_used_for_hip_abduction http://healthyliving.azcentral.com/muscles-hip-abductors-5626.html http://www.athleticquickness.com/hipabductors.asp http://www.answers.com/Q/What_muscles_are_used_for_hip_abduction http://www.livestrong.com/article/84656-hip-abductor-muscles-exercises/ http://www.athleticquickness.com/hipabductors.asp
what are the hip abductor muscles