Carpal tunnel syndrome (CTS) is a cumulative trauma disorder (CTD) affecting the hands and wrists. CTS is the compression and entrapment of the median nerve where it passes through the wrist into the hand in the carpal tunnel.
The median nerve is the main nerve that extends down the arm to the hand and provides the sense of touch in the thumb, index finger, middle finger, and half of the fourth, or ring, finger.
When irritated, tendons housed inside the narrow carpal tunnel swell and press against the nearby median nerve. The pressure causes tingling, numbness, or severe pain in the wrist and hand. The pain is often experienced at night. The pressure also results in a lack of strength in the hand and an inability to make a fist, hold objects, or perform other manual tasks. If the pressure continues, it can damage the nerve, causing permanent loss of sensation and even partial paralysis.
CTS develops in the hands and wrists when repetitive or forceful manual tasks are performed over a period of time. For example, the meatpacking industry is considered one of the most hazardous industries in the United States because workers can make as many as 10,000 repetitive motions per day in assembly line processes, such as deboning meats, with no variation in motion Consequently, stress and strain placed on the wrists and hands often results in CTS.
Today, more than half of all U.S. workers are susceptible to developing CTS. Anyone whose job demands a lot of repetitive wrist, hand, and arm motion, which need not always be forceful or strenuous, might be a potential victim of CTS. CTS is common among meat and poultry workers, letter sorters, carpenters, garment workers, upholstery workers, shoe and boot makers, electronic and other assemblers, packers, product inspectors, machine operators, computer/keyboard operators, and cashiers.
Since the early 1980s, CTS has been reported widely among many service-sector employees, including office workers and newspaper and news service employees who use video display terminals (VDTs). CTS, among other health effects, is becoming a growing problem among VDT users because of the numerous repetitive motions of keystroking data into the computer over long periods.
Compounding problems is the fact that employees are often unaware of the causes of CTS and what to do about them. Initially the person may have fatigue and pain that develops during the workday and disappears overnight with no physical symptoms. After a length of time, fatigue and pain develop earlier in the day, some physical symptoms such as clumsiness may occur, which affect work performance, and there may be no overnight recovery. When the case becomes full-blown, there is constant fatigue and pain with no overnight recovery, and disturbed sleep results.
At this point, work performance is inhibited to the extent of requiring off-duty time or light/restricted duty. Often victims do not associate their pain with their work because symptoms may only occur during evening or off-duty hours. When workers finally seek medical help, they may be given the wrong diagnosis and find the road to recovery takes more time and money than had been anticipated.