1. Wrist and Hand

2. Wrist Radiocarpal Mid-carpal (intercarpal)
maintain length-tension relationship for hand musculature

3. Distal Radius Facets Lateral (46%) scaphoid Medial (43%) lunate
Inferior disk (11%) triquetrum

4. Radiocarpal Radius and Radioulnar disk (concave)
Scaphoid (navicular), lunate, and triquetrum (proximal wrist bones)

5. Ligaments volar - thick, strong dorsal - thinner, fewer
unique function
extrinsic
intrinsic

6. Ligaments
Radiocarpal
superficial
deep

7. Ligaments Ulnocarpal complex
meniscus homologue - radiotriquetral ligament
triangular fibrocartilage - articular disk

8. Kinematics Extension distal carpals on fixed proximal carpals
neutral (scaphoid-capitate close-packed)

9. Kinematics Extension scaphoid travels w/ distal carpals  450 ext.
scaphoid & lunate close-packed  scaphoid travels w/ proximal carpals

10. Kinematics
Flexion
opposite extension

11. Hand Flexor Tendons surrounded by synovial sheaths
reinforced by pulleys (5/3)
minimize force/pressure
prevent bowstringing

12. Flexor Tendons 60  900 of PIP flexion 
40%  in tension in restraining pulley

13. Tendon Excursion and Pulleys

14. Tendon Excursion and Pulleys

15. Tendon Excursion and Pulleys
Sliding of flexor/extensor tendons
proximal jts. > distal joints
FS > FP
Flexors > extensors
Extrinsics > intrinsics

16. Pulley Disruption Bowstringing
 excursion at a joint  weakness at other joints

17. Pulley Disruption

18. Pulley Disruption

19. Balance of Power Extrinsic vs. Intrinsics Intrinsic -  clawing
counteract extrinsics
stabilize proximal phalanx
tendons volar to AOR
lumbricales critical for timing

20. Hand/Wrist Injuries CTD/RSI CTS inflammation in CT
compressive neuropathy

21. Hand/Wrist Injuries Etiology of CTS forceful exertions
repetitive*/prolonged activities
awkward postures
localized contact stresses
vibration
cold temp.

22. Carpal Fractures 80:20% load distribution between radius:ulna
scaphoid (60-70%)
hyperextension beyond 950
lunate

23. Finger Injuries Mallet Finger
distal terminal tendon/slip rupture  flexion of DIP

24. Finger Injuries Boutonniere (Button-Hole) Deformity
dorsal synovitis /capsular distension 
thinning & lengthening of central tendon

25. Finger Injuries Boutonniere (Button-Hole) Deformity
dorsal subluxation of proximal phalanx (PIP) 
palmar displacement (dislocation) of lateral bands of long extensors 
MCP /  PIP  DIP /

26. Finger Injuries Swan-Neck Deformity
Flexor synovitis   flexor forces on MCP
stretching of collateral ligaments and palmar plate at PIP

27. Finger Injuries Swan-Neck Deformity
dorsal displacement of lateral bands of extensors 
intrinsic tightening with MCP flexion 
position of lateral bands  pull of extensor tendon 
reciprocal DIP flexion

28. Finger Injuries
Swan-Neck Deformity
MCP   PIP /  DIP 

29. Thumb Injuries Gamekeeper’s/skier’s thumb
MCP ulnar collateral ligament
20 to tensile loading (chronic or acute)
excessive abduction/hyperextension

30. Thumb Injuries Bennett’s Fx fx subluxation of trapeziometacarpal joint
intraarticular fx of 1st MET
axial compression