Have a sore thumb? It could be RSI

By Divya Sreedharan

and Harichandan A. A.

BANGALORE, FEB. 26. On St. Valentine's Day, happy young thumbs clicked away on cell phone keypads, sending romantic messages. Yet, too much of this could leave them with repetitive strain injuries (RSI), also called repetitive stress injuries.

The name speaks for itself. Use something often and chances are that it will get damaged, if one is not careful. In the case of SMS enthusiasts, the `something' could be strips of a soft tissue called tendons, which connect muscles that terminate on the wrists to the bones of the thumbs.

With RSI, a protective tendon sheath that covers the tendons gets inflamed with much wear and tear. Normally, the tendons glide through the tunnel-like sheath, which is lined with a friction-reducing membrane called synovium. When inflamed, this thin covering of the sheath can thicken to several times its normal size. This means the tendons get less space to move. The tendons can swell up in a balloon-like mass at the point where they pass through the tunnel.

The result can be painful. But the condition is not restricted to those sending SMS or to those who use computers a lot. Barbers, who compulsively snip their scissors in the air, are just as prone. One doctor quipped that the so-called shared secretaries, who handle typewriting assignments from more than one boss, "will know all about RSI". It is not restricted to tendons and fingers either. In a broad sense, it could be "injury caused by repetitive use of any body part", the doctor said.

One of the first RSI recorded was De Quervain's disease, named after the Swiss surgeon who described it in 1895. This is a common type of tendon lining inflammation (also called tenosynovitis). Here, specific tendons to the thumb get inflamed. The swollen tendons and their coverings cause friction within the narrow sheath through which they pass. The result: pain at the thumb base and along the side of the wrist.

But not everyone gets it nor is there data on how many do in India. "In the West there are, because it helps people seek compensation for work-related injuries. But RSI itself is not without controversy, in the context of seeking compensation," the same doctor said.

"The reason is that clinical diagnoses, 98 per cent of which are based on history, i.e., what a patient tells his doctor and how the latter interprets it, are the only way to tell if a person has RSI".

For example, damaged tendons, which are soft tissues, don't show up on X-ray images.

Getting back to RSI, tackling it could involve a simple support for the wrist while typewriting, a job change or sending less SMS.