Which nerve correctly innervates the little finger, ring finger, and half of the middle finger: Ulnar, Radial, or Median nerve?

From the Research

Nerve Innervation of Fingers

The nerve that correctly innervates the little finger, ring finger, and half of the middle finger is the:

• Ulnar nerve, as it provides sensation to the fourth and fifth fingers and medial border of the hand 1
• The ulnar nerve also innervates the dorsal aspect of the proximal part of the ring finger, and its contribution to the dorsal digital nerves decreases from the little finger to the middle finger 2

Specific Innervation Patterns

• The little finger is always innervated by the ulnar nerve 2
• The ring finger is mainly supplied by the dorsal cutaneous branch of the ulnar nerve (DCUN) 2
• The middle finger has dual innervation, with the ulnar nerve and the median nerve contributing to its sensation 2, 3
• The median nerve provides sensation to the palmar aspect of the first three fingers, including half of the middle finger 4

Clinical Applications

• The ulnar nerve innervates all intrinsic hand muscles, except the abductor and flexor pollicis brevis, opponens pollicis, and lateral two lumbricals, which are innervated by C8 and T1 via the median nerve 1
• The median nerve consistently drives flexion of the distal phalanx of the ring and little fingers, even in cases of high ulnar nerve lesion 5