Palmaris longus - Tendon

The tendon of the Palmaris longus muscle is a long, slender structure that originates from the muscle belly of palmaris longus in the proximal forearm and courses distally, becoming superficial in the lower third of the forearm. Proximally, the tendon lies deep to the antebrachial fascia, but it perforates this fascia approximately 4–5 cm proximal to the wrist (bistyloid line), then travels in a suprafascial plane before inserting into the palmar aponeurosis.

The tendon is in continuity specifically with the longitudinal fibers of the superficial layer of the palmar aponeurosis, which is adherent to the skin of the palm.