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TABLE 5.2 Actions of muscles which may restrict movements at the fingers

MUSCLE

Muscles of the forearm

Extensor digitorum communis

Extensor indicis

Extensor digiti minimi

Flexor pollicis longus

Flexor digitorum super-ficialis

Flexor digitorum pro-fundus

Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis

Muscles of the hand

Interossei dorsales^{1 2 3}

Interossei palmares¹

Lumbricales¹

Flexor digiti minimi brevis

Flexor pollicis brevis Adductor pollicis Abductor pollicis brevis Opponens pollicis Opponens digiti minimi Abductor digiti minimi

ACTION

Extends fingers. Flexes at elbow. Supinates forearm.

Dorsal flexes at wrist.

Extends and ulnar deviates index finger. Supinates forearm. Dorsal flexes at wrist.

Extends little finger. Flexes at elbow. Dorsal and ulnar flexes at wrist.

Opposes and flexes thumb. Volar flexes at wrist. May pronate forearm. Flexes at elbow (rarely). Flexes fingers (including at PIP joints). Flexes at elbow. Volar flexes at wrist.

Flexes all finger joints except thumb. Volar flexes at wrist.

Abducts thumb. Radial and volar flexes at wrist. Supinates forearm.

Extends thumb. Supinates forearm. Dorsal and radial flexes at wrist.

Extends thumb at CMC and MCP joints (and often at IP joint). Radial flexes at wrist. Volar or dorsal flexes at wrist (depending on position of hand). Supinates forearm.

Flex at MCP joints. Extend at DIP and PIP joints. Abduct fingers away from axial linę through middle finger.

Flex at MCP joints. Extend at DIP and PIP joints. Adduct fingers toward axial linę through middle finger.

Flex at MCP joints. Extend at DIP and PIP joints.

Flexes at MCP joint of little finger.

Flexes at MCP joint and assists opposition of thumb.

Adducts thumb. Transverse head also opposes thumb.

Abducts thumb at MCP and CMC joints.

Opposes and adducts thumb

Flexes little finger at CMC joint; opposes little finger.

Abducts and flexes at MCP joint of little finger

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1

NOTES: 1. The interossei dorsales, interossei palmares, and/or lumbricales may restrict finger flexion only at the DIP/and PIP joints, and may restrict finger extension only at the MCP joints.

2

   Actions described in terms most relevant to manuał therapy. Cross reference to terms often used in anatomy texts:

Ulnar flexion:    towards ulna, corresponds to adduction (usually of hand)

Radial flexion:    towards radius, corresponds to abduction (usually of hand)

Volar flexion:    towards palm, corresponds to flexion of hand

Dorsal flexion:    towards back of hand, corresponds to extension of hand

3

   Finger joint abbreviations:

CMC Carpo-metacarpal IP Interphalangeal MCP Metacarpo-phalangeal PIP Proximal-interphalangeal