Repetitive strain injury (RSI), also known as Cumulative Trauma Disorder (CTD), occupational overuse syndrome, non-specific arm pain or work related upper limb disorder (WRULD), is a diagnosis used for hand and arm pain that is believed to be caused by chronic misuse, for instance, while using a computer. Conditions such as RSI tend to be associated with both physical and psychosocial stressors.
The following complaints are typical in patients that might receive a diagnosis of RSI:
In contrast to carpal tunnel syndrome, the symptoms tend to be diffuse and non-anatomical, crossing the distribution of nerves, tendons, etc. They tend not to be characteristic of any discrete pathological conditions. A 2008 study showed that 68% of UK workers suffered from some sort of RSI, with the most common problem areas being the back, shoulders, wrists, and hands.
The physical examination discloses tenderness and diminished performance on effort-based tests such as grip and pinch strength. Often tendon stress tests show muscles as weak and spinal joint problems are often found by chiropractors in those with RSI. Diagnostic tests such as x-ray, are normal.
The term “repetitive strain injury” is most commonly used to refer to patients in whom there is no discrete, objective, pathophysiology that corresponds with the pain complaints. It may also be used as an umbrella term incorporating other discrete diagnoses that have (intuitively but often without proof) been associated with activity-related arm pain such as Carpal tunnel syndrome, Cubital tunnel syndrome, Thoracic Outlet Syndrome, DeQuervain’s syndrome, Stenosing tenosynovitis/Trigger finger/thumb, Intersection syndrome, Golfer’s elbow (medial epicondylosis), Tennis elbow (lateral epicondylosis), and Focal dystonia.
Finally RSI is also used as an alternative or an umbrella term for other non-specific illnesses or general terms defined in part by unverifiable pathology such as Reflex sympathetic dystrophy syndrome (RSDS), Blackberry thumb, disputed Thoracic Outlet Syndrome, Radial tunnel syndrome, “Gamer’s thumb” (a slight swelling of the thumb caused by excessive use of a gamepad), “Rubik’s wrist” or “cuber’s thumb” (tendinitis, carpal tunnel syndrome, or other ailments associated with repetitive use of a Rubik’s Cube for speedcubing), “Stylus Finger” (Swelling of the hand caused by repetitive use of mobile devices and mobile device testing.), “Raver’s wrist”, caused by repeated rotation of the hands for many hours (for example while holding glow sticks during a rave).