Upper limb

Intrinsic intercarpal ligaments (Scapholunate, Lunotriquetral, Radiate, etc.)

Ligamenta intercarpalia (SL, LT, STT, Radiate, etc.)

Origin

Articular margins and interosseous zones of all 8 carpal bones

Insertion

Connects proximal and distal carpal rows into a cohesive functional arch

Function

Critical intrinsic stabilizers: Scapholunate (SL) ligament prevents DISI deformity (dorsal intercalated segment instability); Lunotriquetral (LT) prevents VISI; Radiate carpal ligament stabilizes capitate keystone

Innervation

Posterior interosseous nerve and deep branch of ulnar nerve (C6–C8)

Movement & chain

Permits precise micro-motions and Dart-Thrower's motion plane (extension-radial deviation to flexion-ulnar deviation)

Palpation

SL joint palpable 1 cm distal to Lister's tubercle; LT joint palpable dorsoulnarly

Clinical

Scapholunate dissociation ('Terry Thomas sign'); SLAC wrist arthrosis; Lunotriquetral dissociation (VISI); positive Watson scaphoid shift test.

Segmental innervation

C6–C8

In clinical practice

Watson test, Dart-thrower's motion rehabilitation (spares SL ligament stress), and dynamic neuromuscular wrist stabilization

Region in the model

Upper limb