Wrist flexion arises from the two carpal muscles, located on the radial and ulnar surfaces. Two radial and one ulnar muscle provide wrist extension. Supination and pronation are powered by muscle contraction in the forearm.

The thumb is powered by three muscles that form the thenar eminence and provide flexion, abduction, and opposition. The muscles of extension are at the base of the thumb along the radial margin. Movement in the digits depends on action of the flexor and extensor tendons of muscles in the forearm and wrist.

The intrinsic muscles of the hand attaching to the metacarpal bones are involved in flexion (lumbricals), abduction (dorsal interossei), and adduction (palmar interossei) of the fingers.

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