Repetitive Strain Injury

Repetitive strain injury (RSI) is an umbrella term for injuries to parts of the musculoskeletal or nervous system caused by repetitive use, vibrations, compression, or prolonged fixed positions. Also referred to as repetitive stress injury, cumulative trauma disorders (CTDs), and overuse syndrome, RSIs have become increasingly common with the advent of devices requiring repetitive motions, such as keyboards and typewriters.

Signs and Symptoms

Patients with RSI typically experience symptoms such as aching, pulsing pain, tingling, and extremity weakness. Initially, these symptoms may be intermittent, but they tend to increase in frequency and intensity over time. Conditions related to RSI include tendinosis, 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, radial tunnel syndrome, ulnar tunnel syndrome, and focal dystonia.

Risk Factors

Occupational Risk Factors

Most occupational injuries are musculoskeletal disorders, often caused by cumulative trauma. Jobs requiring repetitive motions or prolonged postures, such as those in mining and poultry processing, significantly increase the risk of tendon, muscular, and skeletal injuries. Young athletes are also predisposed due to their underdeveloped musculoskeletal systems.

Psychosocial Factors

Psychosocial factors, including personality differences and workplace organisation issues, can also contribute to RSI. Workers who perceive their work environment negatively due to excessive work rates, long hours, limited job control, and low social support are at higher risk. Elevated stress-related chemicals (urinary catecholamines) have been observed in workers with RSI, and lack of support from colleagues and supervisors can lead to chronic pain syndrome.

Non-Occupational Factors

Age and gender are significant non-occupational risk factors, with the risk increasing with age and being higher in women due to their smaller frame, lower muscle mass, and endocrine influences. Lifestyle choices such as smoking and alcohol consumption further elevate the risk. Obesity and diabetes can predispose individuals to RSIs by creating a chronic low-grade inflammatory response that hinders tissue healing.

Diagnosis

Diagnosis of RSIs involves various objective clinical measures, including effort-based tests like grip and pinch strength, and diagnostic tests such as Finkelstein's test for De Quervain's tendinitis and Phalen's contortion for carpal tunnel syndrome. Imaging techniques, such as x-rays for the wrist and MRI for thoracic outlet and cervico-brachial areas, are very important for early detection and treatment, preventing long-term adverse effects.

Treatment

There are no quick fixes for RSIs, making early diagnosis essential for limiting damage. Initial treatments include the RICE method (Rest, Ice, Compression, Elevation) to reduce swelling and pain. Occupational therapists can aid in teaching proper functional task movements to minimise injury risk. Other early-stage treatments include analgesics, myofeedback, biofeedback, physical therapy, relaxation, and ultrasound therapy. In some cases, RSIs may require more aggressive interventions, including surgery.

Ergonomics, the modification of one's environment to minimise repetitive strain, is an effective approach to both treatment and prevention. A 2006 Canadian study found that leisure-time exercise significantly reduces the risk of developing an RSI. Doctors may recommend specific strengthening exercises to improve posture and reduce conditions like excessive kyphosis and thoracic outlet syndrome.

History

RSIs have been documented in medical literature for centuries. In 1700, Italian physician Bernardino Ramazzini described RSI in various industrial workers. Carpal tunnel syndrome was first identified by British surgeon James Paget in 1854. The Swiss surgeon Fritz de Quervain identified De Quervain's tendinitis in 1895, and the French neurologist Jules Tinel developed his percussion test for median nerve compression in 1900. American surgeon George Phalen's work in the mid-20th century furthered the understanding of carpal tunnel syndrome.

Society

RSI-related discomfort has been popularly referred to by terms such as Blackberry thumb, PlayStation thumb, Rubik's wrist, stylus finger, and raver's wrist, illustrating the broad impact of repetitive strain injuries on various activities.

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Self-assessment MCQs (single best answer)

What is the term used to describe injuries caused by repetitive use, vibrations, compression, or prolonged fixed positions?

Which of the following is NOT a symptom of RSI?

Which of the following conditions is related to RSI?

What occupational activity is mentioned as significantly increasing the risk of RSI?

What factor is NOT listed as a psychosocial contributor to RSI?

Which demographic is at higher risk of developing RSIs?

Which test is used for diagnosing carpal tunnel syndrome?

What initial treatment method is suggested for RSIs?

Which activity was found to significantly reduce the risk of developing an RSI according to a 2006 Canadian study?

Who first identified carpal tunnel syndrome?