Ulnar Nerve Hand Muscles - All But LOAF

Mnemonic

The ulnar nerve supplies every intrinsic muscle of the hand except LOAF:

• L - Lateral two lumbricals
• O - Opponens pollicis
• A - Abductor pollicis brevis
• F - Flexor pollicis brevis

So the ulnar nerve takes the medial two lumbricals, all interossei, adductor pollicis, and the whole hypothenar group. Because the interossei and adductor pollicis are ulnar, an ulnar lesion causes Froment’s sign and clawing of the ring and little fingers.

Expansion

The ulnar nerve supplies everything in the hand except LOAF:

• All interossei (palmar and dorsal)
• The medial two lumbricals
• The three hypothenar muscles
• Adductor pollicis
• Palmaris brevis

A high ulnar lesion causes weakness of these muscles; a claw hand becomes more obvious the lower the lesion (the ulnar paradox).