Musculus flexor accessorius digitorum, commonly known as the accessory flexor muscle of the digits, is a muscular structure found in the forearm of humans and other animals. It is part of the flexor compartment of the forearm and contributes to the movement and control of the fingers.
This muscle is specifically located on the ulnar side (inner side, closest to the little finger) of the forearm. It originates from the medial epicondyle of the humerus, or the bony prominence on the inner side of the elbow. From there, it runs along the ulna bone and crosses both the wrist and palm before finally inserting into the base of the distal phalanges of the four medial (ring, middle, index, and thumb) digits.
The musculus flexor accessorius digitorum works in conjunction with other muscles in the forearm to flex the four medial digits at the metacarpophalangeal, proximal, and distal interphalangeal joints. This muscle also assists in adducting, or bringing the digits closer together.
The activity of the accessory flexor muscle of the digits is mainly controlled by the median nerve, which supplies motor innervation to the muscles of the anterior compartment of the forearm. Through its contraction, this muscle plays a crucial role in fine motor movements of the fingers, such as grasping objects, gripping, and manipulating items with precision.
