Palmaris Longus, Anterior View

Description

Running superficially along the anterior forearm, the palmaris longus is shown as a small proximal muscle belly that tapers rapidly into a long, slender tendon descending toward the wrist in the midline between flexor carpi radialis laterally and flexor carpi ulnaris medially. Proximally, its origin would be inferred at the medial epicondyle of the humerus via the common flexor tendon, with the tendon crossing anterior to the distal radius and ulna to reach the carpal region. Deep to this superficial plane sit the radius (lateral) and ulna (medial), while distally the tendon courses toward the palmar aponeurosis superficial to the flexor retinaculum and carpal bones. Bony context includes humerus, elbow joint, and the carpal, metacarpal, and phalangeal skeleton. A clean surface landmark. This anterior perspective matters because palmaris longus is a high-variability structure that clinicians often test and surgeons frequently harvest, so seeing its long attenuated tendon in relation to the wrist flexion crease and neighboring superficial flexors prevents misidentification. The classic exam maneuver (opposition of the thumb and little finger with wrist flexion) makes the tendon stand out, and this view aligns with that bedside assessment. In the operating room, palmaris longus provides a common autograft for tendon reconstruction and ligament procedures, including palmaris tendon grafting for thumb ulnar collateral ligament repair, and its superficial course helps avoid inadvertent injury to the palmar cutaneous branch of the median nerve during distal forearm incisions. Use this artwork in gross anatomy and upper limb courses to teach the superficial flexor compartment and surface anatomy of the volar forearm, or in surgical education materials covering tendon graft harvest, wrist approaches, and preoperative planning. It also fits hand therapy manuals and clinical skills texts that illustrate tendon palpation and forearm muscle testing. Anatomical accuracy verified by SciePro's Medical Advisory Board.