The muscles of the thumb are nine skeletal muscles located in the hand and forearm. The muscles allow for flexion, extension, adduction, abduction and opposition of the thumb.

Sep 27, 2024 · The thenar muscles are three short muscles located at the base of the thumb. The muscle bellies produce a bulge, known as the thenar eminence . They are responsible for the fine movements of the thumb.

Several muscles in the hands help flex and extend the thumb and fingers. They also help with gripping things and making a fist – basically, anything you do with your hands. These muscles can be divided into two groups based on their point of origin – intrinsic and extrinsic.

Nov 13, 2023 · Learn the attachments, innervation and functions of the thenar muscles faster and easier with our upper extremity muscle charts! The opponens pollicis is a short muscle located deep to the abductor pollicis brevis muscle. It originates from the tubercle of trapezium bone and flexor retinaculum.

The muscles of the hand are redivided into two groups: the extrinsic muscles and the intrinsic muscle groups. The extrinsic groups are the long flexors and extensors muscles. They are termed extrinsic muscles because the muscle belly is positioned on the forearm.

It is comprised of three muscles: the abductor pollicis brevis, the flexor pollicis brevis, and the opponens pollicis. The abductor pollicis brevis pulls the thumb away from the index finger, and the flexor pollicis brevis bends the thumb toward the small finger.

Jun 12, 2023 · There are 19 bones in each of your hands. They’re grouped together by their location and function: Metacarpals: The bones that are in your palm and give it its shape. Phalanges: The individual bones that make up the segments of your fingers and thumb.

The intrinsic muscle groups are the thenar (thumb) and hypothenar (little finger) muscles; the interossei muscles (four dorsally and three volarly) originating between the metacarpal bones; and the lumbrical muscles arising from the deep flexor (and which are special because they have no bony origin) to insert on the dorsal extensor hood mechanism.

Jan 6, 2025 · (a) Posterior extrinsic muscles of the thumb; (b) Intrinsic muscles of the thumb. Also known as thenar muscles [1] Anatomical snuff box (III). Note the scaphoid bone, the wrist joint proximal to the scaphoid, and the midcarpal joint distal to it. [2] ↑ Lujan, Jose Luis.

attaches proximally to radius, and crosses wrist, CMC, MP, and IP joints. only muscle that extends IP joint directly; other muscles attach to thumb's extensor mechanism. can assist with adduction of first MP joint, because its tendon can lie on that joint's ulnar side.