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Repetitive strain injury

Repetitive strain injury is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Repetitive strain injury rather than just read about it. In short: 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 injury, repetitive stress disorders, cumulative trauma disorders, and overuse syndrome.

Repetitive strain injury — main illustration
Repetitive strain injury — illustration

Key takeaways

  • Repetitive strain injury belongs to physics; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Repetitive strain injury to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Repetitive strain injury from memory before moving on to harder problems.

Reference excerpt

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 injury, repetitive stress disorders, cumulative trauma disorders, 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 are musculoskeletal disorders and work-related musculoskeletal disorders. 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. Specific sources of discomfort have been popularly referred to by terms such as Blackberry thumb, PlayStation thumb, Rubik's wrist or "cuber's thumb", stylus finger, raver's wrist, and Emacs pinky. 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 Psychological factors include personality differences concerning 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. Studies show elevated urinary catecholamines (stress-related chemicals) in workers with RSI. Pain related to RSI may evolve into chronic pain syndrome, particularly for workers who do not have supports from coworkers and supervisors.

Non-occupational factors Age and gender are important risk factors for RSIs. The risk of RSI increases with age. Women are more likely affected than men because of their smaller frame, lower muscle mass and strength, and endocrine influences. In addition, lifestyle choices such as smoking and alcohol consumption are recognizable risk factors for RSI. Recent scientific findings indicate that obesity and diabetes may predispose an individual to RSIs by creating a chronic low grade inflammatory response that prevents the body from effectively healing damaged tissues.

Diagnosis RSIs are assessed using a number of objective clinical measures. These include effort-based tests such as grip and pinch strength, diagnostic tests such as Finkelstein's test for De Quervain's tendinitis, Phalen's contortion, Tinel's percussion for carpal tunnel syndrome, and nerve conduction velocity tests that show nerve compression in the wrist. Various imaging techniques can also be used to show nerve compression such as x-ray for the wrist, and MRI for the thoracic outlet and cervico-brachial areas. Utilization of routine imaging is useful in early detection and treatment of overuse injuries in at risk populations, which is important in preventing long term adverse effects.

Treatment

There are no quick fixes for repetitive strain injuries. Early diagnosis is critical to limiting damage. For upper limb RSIs, occupational therapists can create interventions that include teaching the correct approaches to functional task movements in order to minimize the risk of injury. The RICE (Rest, Ice, Compression, Elevation) treatment is used as the first treatment for many muscle strains, ligament sprains, or other bruises and injuries. RICE is used immediately after an injury happens and for the first 24 to 48 hours after the injury. These modalities can help reduce the swelling and pain. Commonly prescribed treatments for early-stage RSIs include analgesics, myofeedback, biofeedback, physical therapy, relaxation, intermittent vacuum therapy and ultrasound therapy. Low-grade RSIs can sometimes resolve themselves if treatments begin shortly after the onset of symptoms. However, some RSIs may require more aggressive intervention including surgery and can persist for years. Although there are no "quick fixes" for RSI, there are effective approaches to its treatment and prevention. One is that of ergonomics, the changing of one's environment (especially workplace equipment) to minimize repetitive strain. A 2006 Canadian study found exercise in leisure time was strongly associated with decreased risk of developing an RSI. Doctors sometimes recommend that those with RSI engage in specific strengthening exercises, for example to improve sitting posture, reduce excessive kyphosis, and potentially thoracic outlet syndrome. Modifications of posture and arm use are often recommended.

… excerpt ends here. Continue reading the full article.

Illustrations

Repetitive strain injury illustration
Repetitive strain injury: Physical Ergonomy: the science of designing the job, equipment, and workplace
Physical Ergonomy: the science of designing the job, equipment, and workplace

Worked examples

Example 1 — a first encounter with Repetitive strain injury

Start with the simplest possible case. Write down what Repetitive strain injury claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Repetitive strain injury before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Repetitive strain injury ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Repetitive strain injury

In research
Repetitive strain injury appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Repetitive strain injury in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Repetitive strain injury is common in secondary-school and first-year university syllabi. It links to neighbouring topics Health risks of performing arts, Musculoskeletal disorders, Occupational diseases, so understanding it makes those chapters shorter.
In everyday life
Look for Repetitive strain injury outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Repetitive strain injury in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Repetitive strain injury means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Repetitive strain injury out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Repetitive strain injury in simple terms?

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 injury, repetitive stress disorders, cumulative trauma disorders, and ov…

Why does Repetitive strain injury matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Repetitive strain injury?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Repetitive strain injury.

Tags

  • Health risks of performing arts
  • Musculoskeletal disorders
  • Occupational diseases
  • Overuse injuries
  • Physical ergonomics

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