Clinical Correlations of the Upper Limb

Vocabulary-style flashcards covering key upper limb nerves, injuries, syndromes, and clinical signs from the lecture notes.

Erb-Duchenne Palsy (Upper Trunk Lesion)

Injury to the C5–C6 nerve roots (upper trunk) causing the classic ‘waiter’s tip’ posture with adducted, medially rotated arm and extended forearm; weakness of shoulder abductors/lators and elbow flexors; sensory loss over the lateral arm/forearm.

Waiter’s Tip Position

Position of the limb in Erb-Duchenne palsy: arm adducted, medially rotated, forearm extended.

Klumpke Paralysis (Lower Trunk Lesion)

Injury to the C8–T1 nerve roots (lower trunk) leading to intrinsic hand muscle weakness and often a claw-like hand; sensory loss along the medial forearm.

Total Claw Hand

Claw hand deformity from loss of interossei and lumbricals, causing hyperextension at MCP joints and flexion at IP joints of the fingers.

Axillary Nerve Injury

Wasting of the deltoid with anesthesia over the lower half of the deltoid and weakness of arm abduction (beyond ~15 degrees).

Radial Nerve Injury

Wrist drop with sensory loss in the posterior arm and dorsum of the hand; inability to extend the wrist and fingers.

Musculocutaneous Nerve Injury

Loss of forearm flexion and supination; sensory loss over the lateral forearm; weakness of the biceps and brachialis.

Hand of Benediction (Median Nerve Injury Above Elbow)

When attempting to make a fist, digits 2–3 remain extended due to loss of median-innervated flexors; thenar muscles affected and pronation weakness.

Ape Hand (Median Nerve Injury Distal/Wrist)

distal median nerve injury leading to atrophy of the thenar eminence and loss of thumb opposition/abduction.

Carpal Tunnel Syndrome

Median nerve entrapment within the carpal tunnel causing paresthesias in the lateral 3.5 digits, thenar weakness, and sometimes pain worsened at night.

Carpal Tunnel Structure

Carpal tunnel formed by the carpal bones and the transverse carpal ligament; contains the median nerve and the flexor tendons.

Ulnar Nerve Palsy

Weakness of intrinsic hand muscles with sensory loss in the ulnar distribution; may present as ulnar claw depending on lesion level.

Froment’s Sign

Positive sign due to weakness of the adductor pollicis; the thumb IP joint flexes to compensate when pinching.

Ulnar Claw Hand

Clawing of digits 4–5 with hyperextended MCPs and flexed IPs from ulnar nerve dysfunction affecting interossei and medial lumbricals.

Canal of Struthers (Cubital Tunnel Location)

Proximal ulnar nerve canal near the medial epicondyle; a potential site of compression affecting ulnar nerve function.

Guyon’s Canal

Ulner canal at the wrist; site of ulnar nerve entrapment affecting intrinsic hand muscles and sensory distribution.

Cubital Tunnel

Ulnar nerve compression behind the medial epicondyle at the elbow; can cause numbness/weakness in the ulnar distribution and hand function.

Distinguishing Ulnar Claw vs Hand of Benediction

Ulnar claw (ulnar nerve injury) shows clawing of digits 4–5; Hand of Benediction (median nerve injury) shows inability to flex digits 2–3 when making a fist.

Serratus Anterior – Action & Innervation

Protracts the scapula; innervated by the long thoracic nerve (C5–C7).

Long Thoracic Nerve

Nerve supplying the serratus anterior; injury causes winged scapula and weakened protraction.

Dorsal Scapular Nerve

Innervates rhomboids and levator scapulae; stabilizes and retracts the scapula.

Suprascapular Nerve

Innervates the supraspinatus and infraspinatus; important for initiation of abduction and lateral rotation of the arm.

Lateral Pectoral Nerve

Innervates the pectoralis major (lateral part) from the lateral cord of the brachial plexus.

Medial Pectoral Nerve

Innervates pectoralis major and minor; contributes to motor function of the chest wall.

Additional Brachial Plexus Nerves (overview)

Nerves like thoracodorsal, upper/lower subscapular, and medial/lateral cutaneous nerves contribute to motor and cutaneous innervation of the upper limb.