Functional demands and consequences of manual communication.

Sign language is the fourth most commonly used language in the United States. Despite the frequent need for this unique upper limb function, little is known regarding the demands and consequences of signing. This article (1) reviews 15 signers with upper limb abnormalities to determine how the abnormalities affect their signing, and (2) explores overuse syndromes in six sign language interpreters. Because of the way the sign language is constructed, only the most severe, bilateral limb abnormalities affect signing, and no extraordinary measures beyond standard, high quality hand care is required to improve function. To treat overuse syndromes in sign language interpreters, customary conservative treatments have generally been useful, but prevention is greatly preferable to treatment.