Associate Professor Oregon Health and Science University Portland, Oregon, United States
Abstract Body : The palmaris longus is a superficial flexor muscle located in the forearm. While it is present and functionally active in 80-96% of the population, it is characterized by high morphological diversity and its tendon crosses the median nerve (MN) at different levels. Typical palmaris longus anatomy consists of a proximal muscle belly originating at the medial epicondyle of the humerus and a long, slender tendon that inserts into the superficial aspect of the palmar aponeurosis. Given that the palmaris longus tendon is routinely harvested for reconstruction of other tendons, knowledge of its variation is clinically important. Common variations include single, double, or multiple bellies of the muscle, reverse palmaris longus orientation, absence unilaterally or bilaterally, duplicated, or accessory palmaris longus muscles, and varying origination and insertion points.
Here we report a palmaris longus variation that was noted during a routine upper right extremity dissection performed by first year medical students at Oregon Health and Science University. The muscle contained proximal tendon originating at the medial epicondyle, with a short, centrally located belly and a distal tendon of typical insertion.
