The flexor pollicis longus muscle is located in the lower half of the arm, from the elbow down. It is an anatomical part that is unique to humans. The muscle extends into the hand and aids with thumb ...

The opponens pollicis muscle is a triangular-shaped muscle in the hand. It is found on and below the thumb. This muscle rotates and flexes the thumb, which enables cupping of the palm. It is one of ...