Repetitive motion injury
Repetitive motion injury (RMI), sometimes called repetitive strain injury, cumulative trauma disorder, or overuse syndrome, is an umbrella term used to describe a variety of diagnostic conditions characterized by pain and discomfort that develop gradually in such soft-tissue structures as tendons, tendon sheaths, nerves, muscles, or blood vessels. Repetitive motion injuries may become progressively worse over time without treatment and may result in a complete loss of function in the affected area. Usually RMIs are associated with occupational causes, although nonoccupational activities, such as sports, hobbies, or driving may also contribute to the problem.
While the term "repetitive motion injury" is relatively new, gaining popularity in the final decades of the twentieth century, the occurrence of RMIs in industry is not new. In 1717, Bernardino Ramazzini, the father of occupationalmedicine, first introduced physicians to the common musculoskeletal disorders that arose from eighteenth-century occupations. As the Industrial Revolution gained momentum and assembly-line production, long hours, poor working conditions, and repetitive motions became the norm, the problem of work-related diseases and conditions was increasingly recognized. By the mid-1950s, automation contributed to a variety of physical and psychological problems.
When computers were introduced into the workplace during the 1980s, RMIs became a worldwide dilemma; the United States witnessed a gradual rise in RMIs from 1980 to 1986. The incidences then rose tremendously from 50,000 in 1985 to281,800 in 1992, according to the Bureau of Labor Statistics. As the reported incidences of RMIs skyrocketed, researchers began documenting and examiningthe prevalence of RMIs in specific high-risk occupations.
Unlike sprains or strains, RMIs are not caused from a single incident. Each cycle of a work activity has the potential to cause microtears in the soft-tissue structures involved. One repetition may not produce inflammation or pain;however, if sufficient time is not allowed for tissue recovery, over time these microtears can accumulate to produce trauma to a specific area of the body. Thus, a worker on the job may be asymptomatic for years, while unknowinglyaccumulating job-related microtraumas.
Although they may develop anywhere in the body, RMIs are most common to the hand and wrist (such as carpal tunnel syndrome, hand-arm vibration syndrome),elbow and forearm (radial tunnel syndrome, cubital tunnel syndrome, tenosynovitis of the forearm extensor and flexor muscles), and shoulder and neck (tension neck syndrome, thoracic outlet syndrome).
The symptoms of an RMI may include one or more of the following: pain, stiffness, swelling, numbness or tingling in the hands, wrists, elbows, shoulders,back or neck; discomfort brought on by performing a particular task, and which then ceases or improves when no longer performing the task, such as on weekends or holidays. Often the discomfort begins in one area, for example neck and back, and then spreads to other parts of the body. Early warning signs maymanifest as sore shoulders or neck pain, particularly when driving home after a day at work, or a loss of flexibility or strength. It is also possible that the effects of RMI may not manifest until the next morning as aches and stiffness in the arms or hands.
Repetitive motion injuries have long presented a problem to the health care professionals in that the injuries are notoriously difficult to diagnose and sometimes to treat, since they develop slowly and are characterized by pain that is not localized to one particular part of the body. Various criteria havebeen developed for detecting the presence of an RMI. These criteria vary depending on the specificity of physical symptoms, duration of time with symptoms, and the use of tests to determine specific diagnoses. The Occupational Safety and Health Administration (OSHA), for example, uses broad criteria to document the number of RMIs in industry. Once a condition is judged as an occupational illness, it must be recorded in the OSHA log.
It is of vital importance to understand why the RMI symptoms occurred in order eliminate the problem. Individuals who engage in repetitive tasks, according to ergonomics experts (ergonomics is the study of the relationship betweenthe worker and the work environment), can prevent RMIs by following some simple guidelines such as varying tasks, avoiding awkward positions and posture,avoiding excessive force in operating equipment, and taking breaks as often as possible.
Most physicians began to accept and take seriously an RMI as a genuine physical problem in the late 1980s and early 1990s. They found that an RMI is verytreatable in its early stages, but even a short delay in seeking rest and treatment can set recovery back by weeks, months or even years.
Treatment options for RMIs generally include: physical treatments (physical therapy, chiropractic, and osteopathy); massage; stretching; postural treatments aimed at correcting bad habits; relaxation (yoga, meditation); exercise; acupuncture; or pain clinics for those suffering from long-term pain. Medication such as nonsteroidal anti-inflammatory drugs may also play a valuable role in treating some individuals.
Future research into RMIs will continue to address the tolerances of human tissues and the body's means of adaptation. This information will help health care practitioners to develop training programs to improve and protect both the health and performance of workers. An additional area of research is the prevention of repetitive motion injuries through appropriate workplace engineering and ergonomic design.