NEW YORK — At the end of a hard day's work, some people complain of aching feet from having to stand all day and others of sore backs from lifting heavy objects.
But an increasing number of workers who perform high-tech jobs and data processing are finding the pain at the end of the day is in their hands and wrists.
The aches, tingling, numbness and burning sensations are linked to carpal tunnel syndrome, a potentially serious nerve disorder that can be disabling.
The National Institute for Occupational Therapy estimates that the syndrome afflicts 23,000 workers a year, many of whom lose use of their hands.
Physical therapists report hundreds of thousands of other workers--who use their hands to type, assemble parts in factories, and work cash registers--have wrist pain, but not the syndrome itself.
More Time on Terminals
"So much of our population is entering jobs that require their hands," said Susan J. Isernhagen, a Duluth, Minn., physical therapist specializing in carpal tunnel syndrome. "People spend more time at video display terminals. Sophisticated electronics require delicate hand skills in assembly.
"They are spending more time doing things that lead to carpal tunnel syndrome," she said.
Carpal tunnel syndrome is named for a narrow tunnel in the wrist formed by ligament and bone, according to the American Physical Therapy Assn.
When the hand is in motion, tendons and nerves slide back and forth through the tunnel. Repeated motions of the hand, especially when it is held at an awkward angle, cause these tendons and nerves to grate along the sides of the tunnel.
Like Frayed Rope
"Think of it as a rope going around the side edge of a building, being pulled back and forth, back and forth," said Isernhagen in a telephone interview. "Pretty soon it's going to get frayed and damaged."
Because of constant irritation, the tendons swell within the narrow tunnel, squeezing the delicate nerves to the hand. If left untreated, the nerve becomes irreparably damaged and muscles begin to deteriorate, the therapists said.
Eventually, the hand can become partially crippled and the damage irreversible.
Isernhagen said some people are predisposed to carpal tunnel syndrome because they have small wrist bones to begin with. He said the disorder often runs in families.
But others become victims of the syndrome because their jobs require constant hand motion at awkward angles.
Some of these are assembly workers, "especially those who get paid by the piece," she said. "They don't want to take the time to relax their hands and wrists because they don't want to lose any of their income."
People who spend all day typing, such as word processors and writers, are also prone to the disorder, she said.
Not all people who suffer wrist pain actually suffer from carpal tunnel syndrome, characterized by damaged tendons and compressed nerves, the therapists said. However, the pain can be acute, and also can be alleviated.
Straight Wrist Urged
The therapists said people who work with their hands should not bend them at an angle. If the wrist remains straight, the tendons within the carpal tunnel are less likely to grate against the sides and become irritated.
Glenda Key, a Minneapolis-based therapist specializing in the syndrome, said companies are designing tools and even typewriters that are less stressful on the wrists.
Specially shaped keyboards prevent typists from bending their wrists to reach for keys, she said in a report to the therapist association, and angled tools help assembly workers keep wrists straight.
According to the association, people with wrist pain should grip heavy objects with their palms facing down, which puts less strain on the tendons, and should use tools with wide handles they can grip easily.
Circulation a Factor
The association also warns against tight clothing, bracelets or watches that can cut circulation to the wrist when it's needed most.
Isernhagen said people with wrist pain should periodically relax their hands at work and flutter their fingers to increase circulation in their wrists.
"Fatigued muscles get tense," she said. "It's hard to get them to relax. Gently rotating your wrist in circles or flexing your fingers helps."
For people who have progressed to the actual syndrome, relieving pain and numbness is much more complicated because of the compressed nerves and damaged tendons.
In one surgical technique, the ligament that surrounds the bundle of tendons and nerves is cut to allow them more room within the narrow tunnel, Isernhagen said.