The number of people suffering from work-related repetitive strain injuries is increasing, according to research.
Health and social work employees are worst affected by RSI
Almost 450,000 UK workers have upper limb disorders, with health and social work employees most affected, says the Chartered Society of Physiotherapy.
Between 2003 and 2004 about 4.7 million work days were lost to RSI, as workers took an average 18 days sick leave.
The society called its findings "shocking" and urged firms to do more to protect workers.
The number of workers with RSI has increased by 52,000 over the past three years, it said.
It also revealed that RSI rates were increasing among workers in communications, transport and education.
The CSP urged people to take precautions, such as taking regular breaks, and to report any symptoms early.
It also called on employers to play their part.
"Employers can make a big difference to the health of their workers, while at the same time improving the productivity and profits of their business" said spokeswoman Jacqui Smith.
"Pain or discomfort caused by upper limb disorders can lead to more sick days and low motivation."