1. Lecture 9
The Forearm and Wrist

3. Distal Radioulnar Joint
Anatomy Review
Distal Radioulnar Joint
Uniaxial pivot joint
Pronation and supination
triangular fibrocartilage disc (TFC)
Radiocarpal ( wrist) joint
condyloid joint
Radius articulates with the scaphoid, lunate and triquetrum
Flexion / extension and ulnar deviation/ radial deviation

4. TFC Disc
Acts as a cushion and shock absorber for the wrist
Major stabilizer of the distal radioulnar joint
Disc articulates with the lunate and the triquetral
Disc can be damages by forced extension and pronation

5. Intercarpal joints
Joints between the individual carpal bones of the proximal row
Scaphoid, lunate and triquetrium
Joints between the individual carpal bones of the distal row
Trapezium, trapezoid, capitate and hamate
Bound together by the intercarpal ligaments (dorsal, palmer and interosseous)
Allows for gliding movement

6. Midcarpal joint
Articulation between the proximal and distal rows ( except pisiform)
Dorsal and palmer ligaments
Greater movement at the mid carpal joint than at intercarpal joints because there is no interosseous ligament

7. Carpometatcarpal joint
At the thumb
saddle joint
flex/ ext , add/abd and rotation
2-5 joints
plane synovial
gliding – flex/ext
dorsal and palmer ligaments

8. Intermetacarpal joints
small gliding , bound together by dorsal and palmer ligaments and interosseous ligaments
does not include thumb
Metacarpophalageal joints
Condyloid joints ( knuckles)
Flex/ ext
Collateral ligaments , tight in flex – relaxed in ext
Palmer and dorsal ligaments
Deep transverse ligaments

9. Interphangeal joints (PIP and DIP)
At the thumb – Ulnar collateral ligament running from the 1st metacarpal to the proximal phalanx – crucial ligament …..
Interphangeal joints (PIP and DIP)
Uniaxial hinge joints
Flex/ext collateral and palmer ligaments

10. Functional Position of the hand
Wrist degrees extension
Ulnar deviation 10 – 15 degrees
Allows for complete flexion of the fingers as it relaxes the long extensor tendons

11. Movement at the wrist and hand
Pronation /Supination
Ulnar and radial deviation
Wrist flex/ext
Finger flex/ext
Finger abd/abb
Thumb flex/ext and abd/add
Muscles ??

12. Carpal tunnel Runs across from the hook of hamate to the trapezium
Contains the median nerve and the tendons of the flexor digitorium profundas and superficialis

13. Special Tests

14. Cascade sign
Metacarpal / phalanax ( fracture)
Watch fingers and knuckles during flexion
All fingers should converge towards the scaphoid
Positive test - If not even or does not cascade suspect a fracture of phalanx or metacarpal

15. Ligament stress test for IP and MP joints
Valgus and Varus
Testing collateral ligaments
Positive tests- more movement

16. Thumb UCL Ligament stress test
Thumb slightly extended apply a valgus stress to the MP joint
Positive test laxity and pain
Testing for the UCL or Gamekeeper’s or skier’s thumb

17. Axial loading (tapping) phalanges
Examiner stabilizes athlete’s wrist
Grasps athletes finger or thumb and applies and axial load (or taps down long axial)
Positive test- pain
May indicate a fracture

18. Ext Pollicis brevis or abductor pollicis longus of thumb
Finkelstein test
Ext Pollicis brevis or abductor pollicis longus of thumb
Determines the presence of DeQuervains disease (tenosynovitis of the Ext Pollicis brevis or abductor pollicis longus of thumb)
Athlete makes a fist with thumb tucked in then ulnar deviates
Positive test – is pain over tendons (often pain is normal therefore must compare sides)

19. Tinels sign at the wrist Median nerve
Examiner taps over the carpal tunnel
Positive test- is tingling into the distribution of the median nerve (thumb, index and middle finger and half of ring finger)

20. Phalens test Median nerve
Athlete flexes wrists together ( back to back)
Positive test- is tingling in the distribution of the median nerve

23. Muscle testing Flexers of the wrist
Flexor Carpi radialis, Flexor Carpi Ulnaris Flexor digitorum superficialis and Palmaris ( % of population missing this one )
Forearm is supinated , fingers in slight flexion
Resistance is applied to palmer surface and examiner pushes into extension
Positive test - pain and weakness

24. Extensors of the Wrist
Extensor Carpi Radialis longus and Brevis, Extensor Carpi Ulnaris, and Extensor digitorum longus
Forearm is pronated , fingers relaxed
Resistance is applied to the dorsum of the hand and examiner pushes into flexion
Positive test -pain and weakness

25. Fingers
Flexor digitorum profundus ( distal phalanx) and flexor digitorum superficialis ( middle phalanx)
Extensor digitorum longus
Thumb
Flexor pollicis longus and brevis
Extensor pollicis longus and brevis
Abductor pollicis longus and brevis
Adductor pollicis

26. Sport Specific Functional Tests
daily living should be assessed for manual dexterity and coordination.
Can they hook, pinch and gasp an object.