repetitive strain injury

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Damage to tendons, nerves, and other soft tissues that is caused by the repeated performance of a limited number of physical movements and is characterized by numbness, pain, and a wasting and weakening of muscles.

Wiktionary

1. n. pathology injury to muscles and tendons caused by continuous repetitive use of particular muscle groups, especially in one's arms and hands, for example by using a keyboard and/or mouse, playing a musical instrument or working on an assembly line