A repetitive strain injury (RSI) is an injury to part of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression or long periods in a fixed position. Other common names include repetitive stress disorders, cumulative trauma disorders (CTDs), and overuse syndrome. Signs and symptoms Some examples of symptoms experienced by patients with RSI are aching, pulsing pain, tingling and extremity weakness, initially presenting with intermittent discomfort and then with a higher degree of frequency. Definition Repetitive strain injury (RSI) and associative trauma orders are umbrella terms used to refer to several discrete conditions that can be associated with repetitive tasks, forceful exertions, vibrations, mechanical compression, sustained or awkward positions, or repetitive eccentric contractions. The exact terminology is controversial, but the terms now used by the United States Department of Labor and the National Institute of Occupational Safety and Health (NIOSH) are musculoskeletal disorders (MSDs) and work-related muscular skeletal disorders (WMDs). Examples of conditions that may sometimes be attributed to such causes include tendinosis (or less often tendinitis), carpal tunnel syndrome, cubital tunnel syndrome, De Quervain syndrome, thoracic outlet syndrome, intersection syndrome, golfer's elbow (medial epicondylitis), tennis elbow (lateral epicondylitis), trigger finger (so-called stenosing tenosynovitis), radial tunnel syndrome, ulnar tunnel syndrome, and focal dystonia. A general worldwide increase since the 1970s in RSIs of the arms, hands, neck, and shoulder has been attributed to the widespread use in the workplace of keyboard entry devices, such as typewriters and computers, which require long periods of repetitive motions in a fixed posture. Extreme temperatures have also been reported as risk factor for RSI. Risk factors Occupational risk factors Workers in certain fields are at risk of repetitive strains. Most occupational injuries are musculoskeletal disorders, and many of these are caused by cumulative trauma rather than a single event. Miners and poultry workers, for example, must make repeated motions which can cause tendon, muscular, and skeletal injuries. Jobs that involve repeated motion patterns or prolonged posture within a work cycle, or both, may be repetitive. Young athletes are predisposed to RSIs due to an underdeveloped musculoskeletal system. Psychosocial factors Factors such as personality differences to work-place organization problems. Certain workers may negatively perceive their work organization due to excessive work rate, long work hours, limited job control, and low social support. Previous studies shown elevated urinary catecholamines (stress-related chemicals) in workers with RSI. Pain related to RSI may evolve into chronic pain