What Is the Abductor Pollicis Brevis?

The abductor pollicis brevis is a hand muscle which controls some of the movement of the thumb. This muscle is responsible for the thumb's abduction, and also plays a role in opposition of the thumb. As a result, the abductor pollicis brevis is a rather important part of human muscular anatomy, and when people develop problems with this muscle, it can be very debilitating.

This flat, roughly triangular muscle emerges from the wrist, crossing over the bottom of the palm to connect with the thumb. It is supplied with blood by the palmar branch of the radial artery, which also brings blood to other areas of the hand, and it is innervated by the median nerve. This muscle actually crosses quite close to the surface of the skin, and is part of a group of muscles which make up the swell of muscular tissue around the thumb's base.

The finely controlled movements the thumb makes are a coordinated effort on the part of several muscles, including the abductor pollicis brevis. These muscles work both in support and in opposition to allow people to very precisely control the thumb's movements, allowing for a high degree of flexibility in the thumb which is not available in other fingers. The thumb's movements are also made possible by the joints in the thumb, which are a bit different from those in the finger.

Abductor pollicis brevis pain can happen to people with repetitive motion injuries, trauma to that area of the thumb, or soreness from certain activities involving the hands. When this muscle becomes inflamed, the thumb can be stiff and difficult to move. In people with severe inflammation, it may not be possible to rotate the thumb, which can cause severe impairment. The abductor pollicis brevis is often involved in cases of carpal tunnel syndrome, with thumb pain and stiffness being one warning sign of carpal tunnel.

Patients who develop problems with this muscle will usually need to see a doctor who specializes in treatment of conditions which involve the hand and wrist. Treatment options can include sprinting and bracing to allow the wrist to heal, along with surgery to correct impairments. Medications may also be administered to bring down inflammation in the thumb and related areas, and patients can use tactics such as icing to reduce swelling further to see if this restores the freedom of movement in the thumb.