Understanding the Function of Abduction in the Body

Moving Away From the Midline

Hip abduction with a cable.
Hip abduction with a cable. MedicalRF.com/Getty Images

Abduct is a kinesiology term which means to move away from the midline or median of the body or from an adjacent part or limb. The median point of the body is referred to as the sagittal plane. The sagittal plane divides the body into even left and right sections.

It is easy to confuse the terms abduction and adduction, which are opposites in regard to movement. A quick way to remember is that abduction takes away, much like the meaning when used as a synonym for kidnapping. Adduction, which means to move closer to the median plane of the body, is the opposite of abduction.

Abduction and Abductor Muscles

Abductor muscles contract to produce abduction. There are several abductor muscles in the body, including in the hips, legs, hands, and feet. Abduction of the fingers and toes spreads the digits away from the center of the hand or foot. Moving the arms out to the side of the body or spreading the legs away from the center of the body are examples of abduction. Lateral arm raises are an abduction exercise.

Hip Abductors

The abductor muscles of the leg are often referred to as the hip abductors and include the gluteus medius muscle (the primary abductor) and the gluteus minimus. The synergist muscles that assist in abduction at the joints include the psoas, piriformis, tensor fascia latae (TFL), sartorius, quadratus lumborum, and rectus femoris.

The abductors move the legs away from the midline of the body when they contract. They also help rotate the thigh in the hip socket and help to stabilize the hip joint. The abductors attach from the pelvis to the femur (thigh bone). Think of hip abduction any time you separate your legs to the side.

You use your hip abductors whenever you step side to side. You also use them when you get out of bed or step into or out of your vehicle. They are essential for standing, walking, and rotating your legs.

Hip abductor exercises can be done lying down (supine), on your knees, or standing. Kneeling exercises include prone hip circles and the fire hydrant. Lying exercises include the clam, straight leg raises on your side, lying windmills, lying crossover, and side planks with leg abduction. Standing and walking exercises include the monster walk, crab walk, lateral band walk, and standing hip circles. Many gyms also have a seated thigh abductor machine and hip abductor machine. You can also use a cable machine with an ankle cuff to do a cable hip abduction exercise.

After a hip fracture, rehabilitation exercises often include standing and supine hip abduction exercises. These can include the addition of an exercise band to add resistance. If you have iliotibial band friction syndrome, you may be given stretching and strengthening exercises for your hip abductors. The most common iliotibial band stretch targets the fascia lata, which is acted on by the TFL abductor muscle. It can be done lying down or standing.