Anatomical Basis of Clinical Features of Erb's Palsy and Klumpke's Paralysis

Introduction

Erb's palsy and Klumpke's paralysis are conditions resulting from injuries to different portions of the brachial plexus. These conditions present unique clinical features based on the anatomical structures involved.

Erb's Palsy

Pathophysiology

Erb's palsy occurs due to injury to the upper trunk (C5-C6) of the brachial plexus, commonly seen in cases of excessive lateral traction on the neck during childbirth or trauma.

Clinical Features

• Weakness in deltoid, supraspinatus, and biceps muscles.
• Arm held in adduction and internal rotation ('waiter's tip' position).
• Impaired elbow flexion and supination.

Klumpke's Paralysis

Muscle Involvement

Klumpke’s paralysis arises from injury to the lower trunk (C8-T1) of the brachial plexus, often caused by excessive arm abduction or traction.

Clinical Presentation

• Weakness in intrinsic hand muscles.
• Claw hand deformity due to unopposed extension of metacarpophalangeal joints and flexion of interphalangeal joints.
• Possible Horner's syndrome if sympathetic fibers are involved.

Conclusion

The distinct anatomical involvement of upper versus lower brachial plexus injuries determines the presentation of Erb's palsy and Klumpke's paralysis. Understanding these patterns aids in diagnosis and targeted rehabilitation approaches.