AN12.1-15 | Forearm & hand — Glossary

A thick fibrous band bridging the carpal bones, forming the roof of the carpal tunnel, attached to the scaphoid and trapezium laterally and pisiform and hook of hamate medially

An osseofibrous tunnel at the wrist containing 9 flexor tendons and the median nerve, bounded by carpal bones and the flexor retinaculum

Compression of the median nerve within the carpal tunnel causing pain, tingling in lateral 3.5 fingers, and thenar muscle wasting

A purely motor branch of the median nerve supplying FDP (lateral half), FPL, and pronator quadratus

A deformity from ulnar nerve injury with MCP hyperextension and IP flexion, most pronounced in the ring and little fingers

A thickened band of deep fascia on the dorsum of the wrist creating six osseofibrous compartments for extensor tendons

A triangular depression on the radial side of the wrist bounded by APL/EPB laterally and EPL medially, with the scaphoid in its floor

The deep branch of the radial nerve, a purely motor nerve supplying all dorsal forearm muscles except brachioradialis and ECRL

A fibrous hood on the dorsum of each finger formed by extensor digitorum, lumbricals, and interossei, allowing coordinated finger extension

Stenosing tenosynovitis of the first extensor compartment (APL and EPB), causing radial-sided wrist pain; tested by Finkelstein's test

An arterial arch in the palm formed mainly by the ulnar artery, giving off common palmar digital arteries to the medial 3.5 fingers

An arterial arch in the palm formed mainly by the radial artery, lying deeper and more proximal than the superficial arch

Four intrinsic hand muscles that flex MCP joints and extend IP joints; lateral two by median nerve, medial two by ulnar nerve

Three muscles that adduct the fingers toward the middle finger (PAD = Palmar ADduct), all supplied by the ulnar nerve

Four muscles that abduct the fingers away from the middle finger (DAB = Dorsal ABduct), all supplied by the ulnar nerve

An infection spreading between the ulnar and radial bursae when they communicate, creating a U-shaped infection pathway

The fleshy mound at the base of the thumb containing opponens pollicis, abductor pollicis brevis, and flexor pollicis brevis

The fleshy mound at the base of the little finger containing opponens digiti minimi, abductor digiti minimi, and flexor digiti minimi brevis

The common flexor sheath enclosing all tendons entering the carpal tunnel, extending from proximal wrist to mid-palm

The synovial sheath enclosing the FPL tendon, extending from the wrist to the thumb's terminal phalanx

Inability to extend the wrist and fingers due to radial nerve injury, with the hand hanging in flexion

A bony prominence on the dorsal radius between the second and third extensor compartments, around which the EPL tendon hooks

An abscess that tracks from palmar fascial spaces through lumbrical canals to dorsal web spaces, creating a dumbbell-shaped infection

The unique movement of the thumb combining flexion, medial rotation, and adduction to touch the tips of other fingers