Main muscles of the upper limb – Anatomy Atlas

Table of Contents

Overview

Upper limb muscles (anterior view)

The muscles of the upper arm can be grouped by region. The most proximal group are the shoulder muscles, specifically the rotator cuff and the deltoid muscles which produce movements of the shoulder joint. Next are the anterior muscles of the arm, also known as the forearm flexors (biceps brachii and brachialis muscles). Distal to these we have the anterior forearm muscles, which flex the hand and fingers. Some of the muscles from this group are the pronator teres, palmaris longus and flexor digitorum superficialis. Lastly, the hand muscles which produce movements of the hand and fingers and include the muscles of the thenar and hypothenar eminence, the lumbrical muscles and palmar interossei muscles.

Upper limb muscles (posterior view)

On the posterior aspect, first we encounter into the posterior compartment of the arm. The only muscle in this region is the triceps brachii muscle, the main extensor of the forearm. Moving distally, we have the posterior forearm muscles, these act as extensors of the hand. Some of the main ones include the extensor digitorum and brachioradialis. Lastly, the main muscles of the posterior aspect of the hand are the dorsal interossei muscles.

Keypoints

Key points
Main muscles of the upper limb	Shoulder muscles: deltoid, supraspinatus, infraspinatus, teres major, teres minor, subscapularis Anterior compartment of arm: brachialis, biceps brachii Posterior compartment of arm: triceps brachii muscle Anterior compartment of forearm: pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, pronator quadratus Posterior compartment of forearm: extensor digitorum, extensor carpi ulnaris, extensor carpi radialis longus, brachioradialis Hand muscles: thenar eminence, hypothenar eminence, dorsal interossei muscles, lumbrical muscles
Main actions of the upper limb muscle groups	Shoulder muscles: abduction, adduction, flexion, extension, internal and external rotation of the shoulder joint Anterior compartment of arm: flexion of the forearm Posterior compartment of arm: extension of forearm Anterior compartment of forearm: flexion of the hand and fingers Posterior compartment of forearm: extension of the hand and fingers Hand muscles: adduction, abduction, flexion, extension and opposition of fingers