Palmaris longus, anteductor of the thumb.

Palmaris longus contributes to the anteposition and pronation of the thumb under circumstances. It is however restricted by its medial tendon which runs into the palmar aponeurosis. The diversion of this tendon and the mobilisation of the muscular head of the abductor pollicis brevis arising from its lateral tendon will substantially accentuate the rôle of palmaris longus as a muscle of the thumb.