Kinesiology

Lesson 12 of 16

Forearm, wrist, and hand

Forearm muscles position the wrist and fingers while also controlling pronation and supination. Many long tendons travel across the wrist into the hand, where small intrinsic muscles refine grip and dexterity. The wrist is a narrow passage containing tendons, nerves, and vessels, so pressure should be adapted carefully. Ask about comfortable hand and finger positions.

Key points

• Wrist flexors and extensors may co-contract to stabilize the wrist during gripping.
• Flexor digitorum superficialis bends the middle finger joints; profundus reaches the distal joints.
• Extensor digitorum extends fingers and contributes to wrist extension.
• Thenar muscles influence thumb opposition and precision grip.
• The hypothenar group supports little-finger movement and cupping of the palm.
• Avoid sustained compression over the carpal tunnel or sensitive nerve pathways.

Key terms

Flexor carpi radialis

O: medial epicondyle; I: bases of second and third metacarpals; A: flexes and abducts wrist.

Flexor carpi ulnaris

O: medial epicondyle and posterior ulna; I: pisiform, hamate, and fifth metacarpal; A: flexes and adducts wrist.

Extensor carpi radialis longus

O: lateral supracondylar ridge; I: base of second metacarpal; A: extends and abducts wrist.

Extensor digitorum

O: lateral epicondyle; I: extensor expansions of digits 2-5; A: extends fingers and assists wrist extension.

Pronator teres

O: medial epicondyle and coronoid process; I: lateral mid-radius; A: pronates forearm and assists elbow flexion.