Texter's Thumb (Curse of the Cellphone)
To mobile phone users: How many messages did you fail to send today? How long have you been punching that keypad with your thumb today? The honest answer of course is "I don't know, I lost count," and "Does it matter?"
Sure it does. The repetitive motion of the thumb can cause injury to the tendon, leaving your thumb frozen, however momentarily, either in a bent or extended position.
The "click" you'll hear won't be coming from your mouse either. It's going to be coming from your hand.
Stenosing tenosynovitis. Also known as "trigger finger" or "trigger thumb," stenosing tenosynovitis is the inflammation of the tendon and its intimate, the tenosynovium or the slick sheath lining that allows the smooth glide of tendons. Tendons are like long ropes attached to the bones. Tendons are the tapered endings of muscles that pull on the bones to make our joints move. Without tendons, there won't be functional connections between muscles, bones, and joints. Now as in any system that uses long ropes, pulleys make work easier. Our hands, in fact, have anatomic pulleys, which keep the tendons near to the bones. These pulleys may constrict the excursion of tendons in tenosynovitis.
Possible causes. The cause of tenosynovitis is still uncertain. Pertinent to "texter's thumb" however, is the idea of abuse. The repetitive, continuous movement of the tendon within its sheath can cause friction. Too much of this may lead to inflammation of both tendon and sheath. Now inflammation can lead to swelling and in fact, "knots" or enlargements of the tendon can occur. These knots of tendon will inevitably bump against the pulley or sheath leading to the phenomenon of "catching." A vicious cycle now results: Inflammation, swelling, catching then more of it.
While this is a mechanical explanation, some researchers point to the "cellular derangement" of the tendon. This is how other conditions like diabetes, gout, and rheumatoid arthritis are implicated as physiologic causes.
So, do you have it? The first symptom is pain at the base of the thumb or fingers. This soreness may be associated with the discovery of a lump right where the pain is. The most common (and distressing!) sign is painful locking of the involved digit. …