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 ...

The thenar eminence refers to the bulge that can be seen at the base of your thumb. It’s made up of three separate muscles that work to control the fine motions of the thumb. We’ll take a closer look ...