Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Upper trunk
Introduction
Overview
The upper trunk (or superior trunk) is a trunk of the brachial plexus which derives from the C5 and C6 roots.
Damage to the upper trunk causes
- Arm hangs by side,
- Elbow can’t flex,
- Arm medially rotated,
- Forearm pronated,
- ‘waiter’s tip’,
- Loss of sensation over deltoid (C5) and lateral upper limb (C6).
The musculocutaneous and median nerves derive largely from this trunk.
Editor-In-Chief: Template:Infobox Nerve C. Michael Gibson, M.S., M.D. [1]