The flexor pollicis longus is a muscle located in the deep compartment of the anterior forearm. It originates from the anterior surface of the radius and the surrounding interosseous membrane. The tendon of the muscle passes through the carpal tunnel, finally attaching to the base of the distal phalanx of the thumb.
The flexor pollicis longus is responsible for flexing the interphalangeal joint and metacarpophalangeal joint of the thumb. It is innervated by the anterior interosseous branch of the median nerve and its blood supply is provided by the ulnar artery.
The flexor pollicis longus is responsible for actions such as the flexion of the thumb, including the ability to bring the thumb towards the palm. In addition, the flexion of the interphalangeal joint of the thumb is enabled by the flexor pollicis longus, necessary for grasping objects. As it is a deep muscle, it is often not visible but may be felt upon physical palpation.
The flexor pollicis longus is particularly important for activities such as playing the guitar. While the flexor pollicis longus is responsible for the flexion of the interphalangeal joint of the thumb, the flexor digitorum profundus is responsible for the flexion of the four fingers. Both muscles work together to allow one to achieve the necessary finger and thumb flexibility for playing the guitar. Without the flexor pollicis longus, one would not be able to effectively press down the strings of the guitar.
The flexor pollicis longus is also directly linked to various work-related activities. For instance, workers who perform repetitive tasks may be affected by the development of carpal tunnel syndrome. This condition is caused by the overuse of the flexor pollicis longus muscle, leading to an entrapment of the median nerve that passes through the carpal tunnel. Symptoms of carpal tunnel syndrome may include tingling of the thumb and fingers, numbness, decreased grip strength, and pain that radiates along with the forearm.
In order to treat carpal tunnel syndrome, a variety of treatments may be recommended by a doctor, such as stretching, physical therapy, splinting, steroid injections, and in some cases, surgical intervention. For those with mild symptoms, an ergonomic work station may be recommended, in order to reduce the stress on the flexor pollicis longus.
In conclusion, the flexor pollicis longus is a crucial muscle located in the anterior forearm. It is responsible for the flexion of the thumb and the interphalangeal joint of the thumb which is necessary for various activities. Its overuse can lead to the development of carpal tunnel syndrome and thus, those with too much strain on the flexor pollicis longus should take measures to reduce the stress on the muscle.
