Wrist and Hand
Specific Readings:
Behnke: pgs 78-101
Thompson and Floyd: pgs. 124-156
Wrist
Key to hand function
8 Carpal bones arranged in two rows:
- Distal Row:
- Proximal Row:
- 8th Bone: Pisiform (medially)
Right Wrist and hand, palmar
surface
ROM
3 Articulations:
| Articulation |
Flexion 65-80° |
Extension 55-75° |
| Radius and 1st row of carpal bones |
~40% |
~67% |
| Proximal & Distal carpal bones |
~60% |
~34% |
When is a grip strongest?
Distal & Metacarpal
Radius and
1st Row
Proximal & Distal
Distal & Metacarpal |
| Radius and 1st Row |
Proximal & Distal |
|
Hand
- Carpometacarpal Joint ® 5 Metacarpals ® Phalanges (Rays 1-5)
- Phalanx Bones: Thumb –2, Others – 3
- Thumb – Metacarpophalangeal Joint (MCP)
2° of freedom: abduction-adduction & flexion-extension
- Between phalanges – hinge joint; 1° of freedom: flexion & extension
- Phalanges – Proximal Interphalangeal Joint (PIP) and
Distal Interphalangeal Joint (DIP)
Grip
2 Types of Grips: Power & Precision
- Power Grip
- Precision Grip
- Ulnar Pinch Grip (Type of Precision Grip)
General things important for gripping:
Innervation
3 Main Nerves:
- Median Nerve
- Radial Nerve
- Ulnar Nerve
| Nerve |
Muscle |
Innervation |
| Median |
Most flexor muscles of wrist (except Flexor Carpi Ulnaris) |
C8 |
| Lumbrical muscles of digits: 2 & 3 |
||
| Radial |
Most extensor muscles of wrist |
C7 |
| Muscles of Thumb: Abductor Pollicis Longus |
C8 |
|
| Extensor Pollicis Brevis Extensor Pollicis Longus |
||
| Ulnar |
Flexor Carpi Ulnaris |
C7-T1 |
| Adductor Pollicis Longus Lumbricals muscles of digits: 4 & 5 |
C7-T1 |
* Muscles of Wrist
Textbook- Chart on page 97
Intrinsic muscles – know actions only