1. Bones, Joints, and Muscles of the Forearm, Wrist, and Hand

2. Terminology
The wrist/hand region consists of 29 bones and multiple joints - which lends to high mobility.
Wrist:
As a joint, it is the articulation between the forearm and hand.
Sometimes, the wrist is discussed as a region, which would include the carpal bones.
Hand
The bones distal to the wrist joint.
As a region, the wrist is part of the hand.

3. Bones 29 bones including: (2 from the forearm, 27 from the hand)
Distal aspect of the radius and ulna
8 carpal (bulk of the hand)
14 phalanges (the fingers)
5 metacarpals
Total: =29

4. Bones
Radius and Ulna
The radius is more massive distally than the ulna
The ulna is more massive proximally than the radius
Remember, forearm pronation and supination are the result of the radius rotating about the ulna

5. Carpal Bones
8 total
2 rows of 4
Proximal row:
pisiform, triquetrum, lunate, scaphoid
Distal row:
hamate, capitate, trapezoid, trapezium

7. Bones - Metacarpals & Phalanges1
Proximal
Distal 2 3 4 5
Phalanges : proximal
middle
distal
Base
Shaft
Head

8. Radiocarpal Joint (wrist joint)
Type: Synovial Condyloid
Articular Surfaces:
Allows for:
flexion
extension
adduction (ulnar deviation)
Abduction (radial deviation)
Radius (distal end)
Prox. Row Carpal Bones

9. Motion - Wrist Joint Adduction (ulnar deviation)
And of course, circumduction
Abduction (radial deviation)

10. Motions of the Phalanges
Extension
Flexion +
Circumduction
Adduction
Abduction

11. Thumb Motion Abduction / Adduction sagittal plane Flexion / Extension
frontal plane
Opposition

12. Forearm Pronators and Supinators
Biceps Brachii
Supinator
Brachioradialis
Pronators:
Pronator Teres
Pronator Quadratus
Brachioradialis

13. Pronator Teres O: Medial Epicondyle of Humerus
I: Medial and Lateral Surface of Radius
A: Pronation of Radioulnar Joint
Integrated Function: Assists in deceleration of supination of radioulnar joint
Assists in dynamic stabilization of radioulnar joint

14. Pronator Quadratus O: Distal anterior ulna I: Distal anterior radius
A: Forearm Pronation
Integrated Function: Assists in deceleration of supination of radioulnar joint

15. Supinator O: Lateral Epicondyle of Humerus
I: Wraps around proximal radius
A: Supination of Radioulnar Joint
Integrated Function: Assists in deceleration of pronation of radioulnar joint
Assists in dynamic stabilization of radioulnar joint

16. Superficial Forearm Pronator and Wrist Flexors
Pronator Teres
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris

17. Muscles Causing Wrist Actions
Wrist flexors
Flexor Carpi Radialis
Flexor Carpi Ulnaris
Palmaris Longus
Wrist extensors
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis
Extensor Carpi Ulnaris
These muscles do not cause finger movements

18. Phalange Muscles These muscles assist in wrist actions Finger flexors
Flexor Digitorum Superficialis
Flexor Digitorum Profundus
Thumb flexor
Flexor Pollicis Longus
Finger extensors
Extensor Digitorum
Extensor Indicis
Extensor Digiti Minimi
Thumb extensor
Extensor Pollicis Longus
Extensor Pollicis Brevis
These muscles assist in
wrist actions

19. Attachments Wrist Flexors
All originate from the medial epicondyle of the humerus
Insertions: anterior aspect of the wrist and hand
Wrist Extensors
All originate from the lateral epicondyle of the humerus
Insertions: posterior aspect of wrist and hand

20. Attachments Wrist Abductors Wrist Adductors
Origin: anterior or posterior aspect of forearm
Insertion: radial side of hand
Wrist Adductors
Insertion: ulnar side of hand

21. Flexor Carpi Radialis O: Medial Epicondyle of Humerus
I: Bases of 2nd and 3rd metacarpals
A: Flexion and Abduction of wrist (radial deviation)

22. Flexor Carpi Ulnaris O:Medial Epicondyle of Humerus I: Pisiform
A: Flexion and Adduction of Wrist (ulnar deviation)

23. Palmaris Longus Absent in 15 - 20% of Population
O: Medial Epicondyle of Humerus
I: Palmar Aponeurosis
A: Wrist flexion
Q: How do you test for this muscle and why is it important?

24. Palmaris Longus Tested: With wrist slightly flexed
Oppose thumb and little finger
Importance:
Used in tendon transfers (autografts)

25. Flexor Digitorum Superficialis
O: Medial Epicondyle of Humerus
I: 2nd through 5th Phalanges
A: Finger Flexion and Wrist Flexion

26. Integrated Function of Wrist Flexors
Assists in deceleration of wrist extensors
Assists in dynamic stabilization of the wrist and hand
Flexor Carpi Radialis and Flexor Carpi Ulnaris:
Assists in deceleration of wrist abdution
Flexor Digitorum Superficialis:
Assists in deceleration of finger extension

27. Extensor Carpi Radialis Brevis
O: Lateral Epicondyle of Humerus
I: Base of 3rd metacarpal on dorsal surface
A: Extension of wrist
Abduction of Wrist

28. Extensor Carpi Radialis Longus
O: Lateral Epicondyle of Humerus
I: Base of 2nd metacarpal
A: Extension of wrist
Abduction of wrist
(radial deviation)

29. Extensor Carpi Ulnaris
O: Lateral Epicondyle of Humerus
I: Base of 5th metacarpal on dorsal surface
A: Extension of Wrist
Adduction of Wrist (ulnar deviation)

30. Integrated Function of Wrist Extensors
Assists in deceleration of wrist flexion
Assists in dynamic stabilization of the wrist and hand
Extensor Carpi Radialis Brevis and Longus:
Assists in deceleration of wrist adduction
Extensor Carpi Ulnaris:
Assists in deceleration of wrist abduction

31. Nerves Three primary nerves of the wrist and hand: Radial Nerve
Innervates the triceps brachii and provides sensation to dorsal side of thumb, index, middle, and half of ring finger
Ulnar Nerve
Palmar side of the little finger and half of the ring finger
Median Nerve
Palmar side of thumb, index , and half of ring finger

33. Common Medical Conditions
Fractures, strains, sprains, dislocations
Scaphoid bone is most frequently fractured carpal bone
“Hook” of the Hamate fracture

34. Common Medical Conditions
Boutonniere Deformity and Mallet Finger
Caused by the rupture of the extensor tendon
Any extensor tendon

35. Carpal Tunnel Syndrome
A disorder that causes numbness in the hand and pain in the wrist due to the compression of the median nerve

36. Carpal Tunnel Syndrome
Etiology:
Short, repetitive movement, such as typing, knitting, and using vibrating tools for hours on end
The lack of rest in between these motions irritates and inflames the flexor tendons that travel with the median nerve to the hand through an area in the wrist called the "carpal tunnel," which is surrounded by bones and a transverse ligament.
The inflamed tendons squeeze the nerve against the ligament.

37. Carpal Tunnel Syndrome
The symptoms Include:
Pain, numbness, or tingling in your hand and wrist, especially in the thumb and index and middle fingers; pain may radiate up into the forearm
Increased pain with increased use of your hand, such as when you are driving or reading the newspaper
Increased pain at night
Weak grip and tendency to drop objects held in the hand
Sensitivity to cold
Muscle deterioration especially in the thumb (in later stages).
Treatment:
Diagnosis by physician
Occupational Therapy/Physical Therapy

38. Prevention of Carpal Tunnel Syndrome
Ergonomics:
Proper seating
The height of your seat and the position of your backrest should be adjustable
The chair should be on wheels so you can move it easily
If you can adjust your table, set your waist angle at 90 degrees, then adjust your table so that your elbow makes a 90 degree angle when your hands are on the keyboard

39. Prevention of Carpal Tunnel Syndrome
Ergonomics:
Elbow angle at 90 degrees. Try to hold your elbows close to your sides to help minimize "ulnar displacement" the sideways bending of the wrist (as when reaching for the "Z" key)
Waist angle at 90 degrees
With your elbows and waist at 90 degree angles, your feet should rest comfortably flat on the floor.

41. Carpal Tunnel Syndrome Exercises
Stretch the following muscles:
Elbow Flexors
Wrist Flexors
Finger Flexors
This will reduce the compression of the median nerve within the carpal tunnel
EXTENSION EXERCISES ARE THE KEY TO RECOVERY
Strengthen the following muscles:
Elbow Extensors
Wrist Extensors
Finger Extensors
Finger Abductors
This will help hold the carpal tunnel open