Upper limb

Carpometacarpal and intermetacarpal ligaments (CMC & MC joints)

Ligamenta carpometacarpalia et intermetacarpea

Origin

Distal carpal row (trapezium, trapezoid, capitate, hamate) and metacarpal bases I–V

Insertion

Bases of metacarpals I–V and deep transverse metacarpal ligament interconnecting heads II–V

Function

Anchors metacarpals to carpus; creates rigid central pillar (CMC II–III) while allowing mobile thumb opposition (CMC I saddle joint) and palmar cupping (CMC IV–V)

Innervation

Median, deep ulnar, and posterior interosseous nerves (C6–T1)

Movement & chain

Saddle opposition/reposition in CMC I; palmar flexion/cupping in CMC IV–V during grasping

Palpation

Palpable along dorsal metacarpal bases and at the thumb CMC joint line

Clinical

Thumb CMC osteoarthritis (rhizarthrosis, positive Grind test); Bennett and Rolando fracture-dislocations of 1st metacarpal base.

Segmental innervation

C6–T1

In clinical practice

Thumb spica splinting, CMC Grind test, thenar muscle strengthening, and trapeziectomy rehabilitation

Region in the model

Upper limb