repetitive strain injury (RSI) Pain and reduced mobility in a limb, most often the wrist, caused by constant repetition of the same movements. The symptoms arise from inflammation of the tendon sheaths because of excessive use. RSI is an occupational disorder mostly seen in assembly-line workers and keyboard operators.

repetitive strain injury (RSI) (ri-pet-it-iv) n. pain in an upper limb associated with frequent repetition of a particular movement, usually related to keyboard usage. Symptoms often occur in the absence of clear signs, such as tenosynovitis or tendovaginitis.