Where in the human body is the "Thenar Eminence"?

The "Thenar Eminence" refers to a group of three short muscles located at the base of the thumb. This group of muscles forms a “fleshy mass” on the lateral side of the palm which is responsible for the thumb’s fine movements.The word thenar comes from Greek (thenar), meaning 'palm of the hand'.

The following 3 muscles are considered part of the thenar eminence.

The “Abductor pollicis brevis” abducts the thumb.

The “Flexor pollicis brevis”, which lies next to the abductor, will flex the thumb, curling it up in the palm.

The “Opponens pollicis” lies deep to “abductor pollicis brevis”. As its name suggests it opposes the thumb, bringing it against the fingers. This is a very important movement, as most of human hand dexterity comes from this action. All 3 muscles are innervated by the recurrent branch of the median nerve.

Because the thumb is the most mobile of all the fingers, it is susceptible to repetitive movements and pain with overuse. The thenar muscles allow the thumb to move in all different directions, making the thumb essential in many daily activities.