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, golfers 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.
Toxic amblyopia, or nutritional optic neuropathy, is a condition where a toxic reaction in the optic nerve results in visual loss. Various poisonous substances may cause the condition as well as nutritional factors.Tobacco amblyopia is a form of toxic amblyopia caused by tobacco containing cyanide. Tobacco amblyopia is marked by a gradual impairment of vision characterised by visual field defects and hindered central vision. Methyl alcohol amblyopia occurs through acute poisoning by methyl alcohol and may lead to complete blindness. Since the term toxic amblyopia is a misnomer according to modern definition of amblyopia, it is now more accurately termed as toxic retinopathies or neuropathies. == References ==