1. Hand Bones Pisiform Triquetrum Lunate Scaphoid Trapezium Trapezoid
Capitate
Hamate

2. Hand Bones

3. Hand joints Carpometacarpal joint(s) – (CMC)
Metacarpophalangeal joints – (MCP)
Interphalangeal joints (proximal & distal)
1st digit (IP)
2-5 digits (PIP and DIP)

4. Movements of the Wrist flexion and extension
adduction (ulnar deviation) and abduction (radial deviation)

5. Tips for the forearm muscles
Flexors and Palmaris longus (medial epicondyle) *flexor digitorum profundus
Extensors (lateral epicondyle)
“carpi radialis” – radial deviation (abduction)
“carpi ulnaris” – ulnar deviation (adduction)

6. Flexor carpi radialis O:. Medial epicondyle of humerus I:
Flexor carpi radialis O: Medial epicondyle of humerus I: Base of second and third metacarpals, anterior (palmar surface) A: wrist flexion, abduction of wrist, weak elbow flexion, weak pronation of forearm

7. Palmaris longus O:. Medial epicondyle of humerus I:
Palmaris longus O: Medial epicondyle of humerus I: Palmar aponeurosis of 2nd, 3rd, 4th, and 5th metacarpal A: Wrist flexion, weak elbow flexion

8. Flexor carpi ulnaris O:. Medial epicondyle of humerus,posterior
Flexor carpi ulnaris O: Medial epicondyle of humerus,posterior aspect of proximal ulna I: Pisiform, hamate, and base of 5th metacarpal (palmar surface) A: wrist flexion, adduction of wrist, weak elbow flexion

9. Superficial Layer (Anterior Surface)
* Pronator teres (2nd)
Flexor carpi radialis (3rd)
Palmaris longus (4th)
Flexor carpi ulnaris (pinky)

10. Extensor carpi ulnaris O:. Lateral epicondyle of humerus, middle
Extensor carpi ulnaris O: Lateral epicondyle of humerus, middle two-fourths of posterior border of ulna I: Base of 5th metacarpal (dorsal surface) A: wrist extension, wrist adduction, weak extension of elbow

11. Extensor digiti minimi O: Lateral epicondyle of humerus I: Base of middle and distal phalanxes of 5th phalange A: Extension of little finger at MCP joint, weak wrist and elbow extension

12. Extensor digitorum O: Lateral epicondyle of humerus I: Four tendons to bases of middle and distal phalanges of four fingers (dorsal surface) A: Extension of 2nd, 3rd, 4th, and 5th phalanges at MCP joints, extension of wrist, weak extension of elbow

13. Extensor carpi radialis brevis O:. Lateral epicondyle of humerus I:
Extensor carpi radialis brevis O: Lateral epicondyle of humerus I: Base of 3rd metacarpal (dorsal surface) A: extension of wrist, abduction of wrist, *weak elbow extension

14. Extensor carpi radialis longus O:
Extensor carpi radialis longus O: Lower third lateral supracondylar ridge and lateral epicondyle of humerus I: Base of 2nd metacarpal (dorsal surface) A: Extension of wrist, abduction of wrist, *weak elbow extensor, weak pronation

15. Superficial Layer (Posterior)
Extensor carpi ulnaris
Extensor digiti minimi
Extensor digitorum
Extensor carpi radialis brevis
Extensor carpi radialis longus
Brachioradialis*

16. Torque Defined as “rotary” force
Torque is the product of linear force (F) and the force’s moment arm (d┴)
T = Fd┴
T = F┴d
Torque is created when linear force acts away from the axis of rotation
Joint movements are rotational movements and thus are generated from torque

17. Illustration of Torque

18. Torque and Muscle Force

19. Levers
A lever is a rigid bar that rotates about an axis of rotation or fulcrum
Levers represent the interaction of muscle torque (from linear force (F)) and resistive torque (from linear resistive force (R))
There are three different classes of levers (Class I, II, III)

20. Different Types of Levers

21. Three Classes of Levers

22. Class II levers will emphasize force or torque production
Levers will emphasize two different functions depending on the location of F and R (length of moment arm) in relation to the fulcrum or axis of rotation.
Large torque production
Large ROM and speed
Class II levers will emphasize force or torque production
Class III levers will emphasize large ROM and speed (human body is comprised mostly of Class III levers)