Muscles Most Used by Guitarists

Fingerpicking, strumming, and fretting require coordinated use of extrinsic (forearm) and intrinsic (hand) muscles. Below is a breakdown by function and location:

• Flexor digitorum superficialis – Flexes middle phalanges (PIP joints) of fingers.
• Flexor digitorum profundus – Flexes distal phalanges (DIP joints); enables full finger flexion.
• Flexor pollicis longus – Flexes thumb.
• Flexor carpi radialis / Flexor carpi ulnaris – Flex wrist (radial and ulnar deviation respectively).

• Extensor digitorum – Extends fingers.
• Extensor indicis / digiti minimi – Extend index and little fingers individually.
• Extensor pollicis longus / brevis – Extend the thumb.
• Abductor pollicis longus – Abducts the thumb (moves it away from the hand).

• Abductor pollicis brevis
• Flexor pollicis brevis
• Opponens pollicis
• Adductor pollicis

1. > Used heavily in picking, opposing thumb to fingers, and fast thumb articulation.

• Abductor digiti minimi
• Flexor digiti minimi brevis
• Opponens digiti minimi

1. > Assist in grip and hand positioning on the fretboard.

• Lumbricals – Flex MCP joints and extend IP joints; fine motor control.
• Dorsal interossei – Abduct fingers (spread).
• Palmar interossei – Adduct fingers (bring together).

1. > Critical for chord formation, finger independence, and precise articulation.

• Wrist stabilizers – e.g. *extensor carpi radialis longus/brevis*
• Forearm rotators – *pronator teres*, *supinator* (rotate hand position)
• Elbow flexors – *biceps brachii*, *brachioradialis* (support posture and positioning)

Note: Repetitive stress in these muscles is common in guitarists and may lead to conditions like tendinitis or carpal tunnel syndrome. Proper technique and stretching are essential.