Wrist and Hand

flexion and ulnar deviation

distal radius, ulna, TFCC, and the proximal carpal row

Radioulnar ligaments

radius during pronation and supination

joint congruency, large space between triquetrum and ulna

forces trasmitted through the wrist on the medial side

ECU tendon

proximal row and the distal row of carpal bones

capitate

distal carpal row and proximal metacarpals 2-5

proximal radiocarpal - convex on concave
midcarpal - convex on concave
distal - concave on convex

scapholunate and lunotriquestral
keep the proximal row together so that they move as a unit

Extensor Carpi Radialis Longus and Brevis, Extensor Carpi Ulnaris
Assistors - ED

Flexor carpi radialis, flexor carpi ulnaris, palmerus longus
Assistors - FDS and FDP and FPL

Prime - Extensor Carpi radialis longus and flexor carpi radialis
Assistors - APL, EPL and brevis

Prime - FCU, ECU

concave on convex

2

ab/adduction - convex on concave
flexion/extension - concave on convex

ECRB - extends the wrist, followed by ECU and ECRL when force increases

20-30 degrees of wrist extension

Extrinsic - FDS and FDP (with ED and ECRB)
Intrinsic - Interossei and Lumbricals

active contraction: interossei and finger flexors
passive tension: lumbricals (flexion torque)
synergy: ECRB to offset flexion moment + optimize length tension of long finger flexors
Stabilize: ED at MCP

extrinsic - ED, EI, EDM
Intrinsic - Interossei and Lumbricals
all are actively contracting!

ED extends the wrist and flexes the fingers - don't want finger flexion!
fix - contract lumbricals and interossei to pull on the extensor hood and not allow MCP hyperextension
Combat Wrist Extension - use FCR