Waiter's Tip Sign

A deformity in which an infant’s arm hangs loosely at the side, and the partially paralysed hand is deviated posteriorly, a position fancifully likened to a waiter subtly accepting a tip; the sign is classically caused by birth-related trauma to the upper brachial plexus
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.