The flexor digitorum superficialis is a muscle located in the intermediate compartment of the anterior forearm. This muscle originates from both the medial epicondyle of the humerus and the radius (Fig. 1). The muscle divides into four tendons at the wrist, which travel through the carpal tunnel and attach to the base of the middle phalanx of the four digits.
The flexor digitorum superficialis has two primary actions. Firstly, it flexes the metacarpophalangeal joints and the proximal interphalangeal joints of the four fingers. Secondly, the muscle flexes the wrist. The median nerve is responsible for innervating the flexor digitorum superficialis. Additionally, the muscle is supplied with ulnar artery as it's primary blood supply.
The flexor digitorum superficialis muscle has two heads, which arise from the medial epicondyle of the humerus and the shaft of the radius. Its primary action is to flex the metacarpophalangeal joints and the proximal interphalangeal joints of the four fingers. Along with this action, the muscle also flexes the wrist.
The flexor digitorum superficialis is innervated by the median nerve. It is supplied with ulnar artery, which is a branch of the brachial artery.
Clinically, the flexor digitorum superficialis is one of the most commonly injured muscles in the forearm. Injury to the muscle can be caused by a direct blow, such as a punch or fall. It can also be caused by overuse, such as playing a sport or working for long periods of time with tools. Injury to the flexor digitorum superficialis can lead to difficulty flexing the hand and fingers, as well as a weakened grip.
In some cases, injury or dysfunction of the flexor digitorum superficialis can lead to an enlarged muscle, known as a pseudohypertrophy. This can cause pain and discomfort in the forearm, as well as weakness and fatigue in the hand. Treatment of these conditions typically involves exercises to strengthen the muscle, and sometimes physical therapy or surgery may be necessary.
In order to diagnose a flexor digitorum superficialis injury, a physical examination is typically performed. This includes checking the range of motion and strength of the muscle, as well as palpating and feeling the area for any tenderness. In more severe cases, imaging scans such as an MRI or ultrasound may be necessary to further investigate the injury.
The flexor digitorum superficialis is an important muscle of the forearm, responsible for flexing the wrist and fingers. Injury to this muscle can lead to pain, discomfort, and loss of strength and mobility in the hand and fingers. It is therefore important to be aware of the signs and symptoms of a flexor digitorum superficialis injury, as well as how to properly diagnose and treat it.
