Upper limb nerve injuries Flashcards
Radial Nerve
Nerve root
Motor and sensory function
Radial nerve (C5-C8)
Motor function: Extension (forearm, wrist, fingers, thumb)
Sensory function: Small area between the dorsal aspect of the 1st and 2nd metacarpals
Radial nerve injury
Common mechanism
Features
Mechanism: Humeral midshaft fracture
Features: Palsy results in wrist drop
Musculocutaneous nerve
Nerve root
Motor and sensory function
Injury
Musculocutaneous nerve (C5-C7)
Motor: Elbow flexion (supplies biceps brachii) and supination
Sensory: Lateral part of the forearm
Injury: Isolated injury rare - usually injured as part of brachial plexus injury
Axillary nerve
Nerve root
Motor and sensory function
Axillary nerve (C5,C6)
Motor: Shoulder abduction (deltoid muscle)
Sensory: Inferior region of the deltoid muscle
Axillary Nerve injury
Common mechanism
Features
Mechanism of injury: Humeral neck fracture/dislocation
Feature of injury: Results in flattened deltoid
Median nerve
Nerve root
Motor and sensory function
Median nerve (C6, C8, T1)
Motor: LOAF* muscles
Sensory: Palmar aspect of lateral 3½ fingers
Median Nerve injury
Common mechanism
Features
Mechanism: Wrist lesion → carpal tunnel syndrome
Features depend on the site of the lesion:
- wrist: paralysis of thenar muscles, opponens pollicis
- elbow: loss of pronation of forearm and weak wrist flexion
Ulnar Nerve
Nerve root
Ulnar nerve (C8, T1)
Motor: Intrinsic hand muscles except LOAF*, Wrist flexion
Sensory: Medial 1½ fingers
Ulnar Nerve injury
Common Mechanism
Features
Common Mechanism: Medial epicondyle fracture
Features: Claw Hand
Long thoracic Nerve
Motor
Mechanism of injury
Features of injury
Long thoracic nerve (C5-C7)
Motor: Serratus anterior
Mechanism of injury: Often during sport e.g. following a blow to the ribs, possible complication of mastectomy
Features of injury: winged scapula
