The flexor carpi ulnaris is a muscle located in the forearm. Its main action is to help move the wrist and hand, and it is used for many different daily activities. The secondary action of the muscle is to help another muscle, the extensor carpi ulnaris, twist and deviate the wrist. An example of an action that would use this muscle is pulling a rope toward the body.
The muscle begins on the medial side of the humerus, meaning closes to the center of the body. From there it runs all the way down the forearm before attaching to the fifth metacarpal, the bone at the base of the pinky finger. There are actually two heads to the muscle — the humeral and ulnar. The ulnar head of the muscle originates in a different location to the humerus.
The tendon associated with the flexor carpi ulnaris is located on the distal area of the forearm, meaning near the wrist. At this location, there will usually be three tendons, with the one associated with this muscle closest to the little finger. In some people, the second tendon may not be present at all. The muscle runs from the elbow down to the hand and an injury can affect a number of different movements.
There are two main actions of this muscle. The first is to help flex the wrist, which is an extremely common action that a person performs many times daily. The second is to deviate the wrist, which in medical terms is called ulnar deviation or wrist adduction, which means to move it to the side toward the pinky. To perform this action, the flexor carpi ulnaris works with other muscles in the forearm.
Two closely related muscles are the flexor carpi radialis and extensor carpi ulnaris. Both of these muscles start at the elbow and run down the arm to the wrist and hand. They are also involved in movement of the wrist. For example, the flexor carpi radialis is used to flex the wrist while the extensor carpi ulnaris extends the wrist.
A common injury associated with the flexor carpi ulnaris is golfer’s elbow. As the name suggest, this is a repetitive strain injury that commonly affects the elbow and is most often found among golfers and throwers. Symptoms include pain inside the elbow, a weakened wrist, and pain on rotating or flexing the wrist. Treatment usually involves rest and ice to begin with, along with bracing the injured area.
