repetitive stress injury

Repetitive stress injury

Repetitive stress injury also called repetitive strain injury (RSI), overuse injury, work-related upper limb disorder, non-specific upper limb pain or cumulative trauma disorder, is a general term used to describe the pain felt in muscles, nerves and tendons caused by repetitive movement and overuse. Repetitive stress injury is usually associated with repetitive hand movements such as typing, but any part of the body can be affected. Repetitive strain injury (RSI) can affect the tendons and muscles of the fingers, hands, wrists, elbows, shoulders, back and neck.

Repetitive strain injury mostly affects parts of your upper body, such as the:

  • forearms and elbows
  • wrists and hands
  • neck and shoulders.

There are certain jobs and activities that can cause repetitive stress syndrome, including:

  • Working on an assembly line.
  • Sewing.
  • Playing a musical instrument.
  • Working on the computer.

All of these jobs and activities can put a lot of repeated stress on your hands and arms. When you push these body parts to their limit, it often results in repetitive stress syndrome.

An repetitive stress injury typically stems from:

  • Training errors. Training errors can occur when you take on too much physical activity too quickly. Going too fast, exercising for too long or simply doing too much of one type of activity can strain your muscles and lead to an overuse injury.
  • Technique errors. Improper technique also can take its toll on your body. If you use poor form as you do a set of strength training exercises, swing a golf club or throw a baseball, for example, you may overload certain muscles and cause an overuse injury.

Repetitive stress disorder symptoms include swelling, pain and weakness in the affected joints. Vulnerable tendons can be overworked and inflamed by repetitious manual tasks such as working on a keyboard, working on an assembly line or even playing a musical instrument.

If you develop symptoms of repetitive stress injury and think it may be related to your job, speak to your employer or occupational health representative. In consultation with your occupational health and safety officer you can devise ways to change and improve work practices and workspace design.

It may be possible to modify your tasks to improve your symptoms.

See your doctor or physical therapist if symptoms continue, despite attempts to change how you work.

Rest is usually the best cure. Sometimes poor workspace design or work practices contribute to occupational overuse syndrome. Making minor changes can alleviate or prevent overuse syndrome.

Can repetitive stress injury cause arthritis?

There’s no known link between repetitive stress injury and arthritis, though repetitive stress syndrome can lead to some other ailments, including:

  • Tendinitis.
  • De Quervain’s tenosynovitis (irritation in the wrist and thumb tendons).
  • Stenosing tenosynovitis (swollen flexor tendons).
  • Capsulitis (inflamed ligaments).
  • A muscle or tendon strain.

Repetitive stress injury causes

Repetitive stress injury is commonly related to the overuse of muscles and tendons in your upper body, caused by repetitive movement, constant muscle contraction or straining, forceful movements, or awkward postures in a work environment causing soft tissue injury without sufficient recovery time. In other words, the rate of injury exceeds the rate of healing in the tissue. The greater and/or the more sustained the forces involved in a repetitive activity, the greater the chance of developing an overuse injury. Jobs that can lead to occupational overuse syndrome include office work (eg: keyboard use), manual work (eg: lifting and carrying heavy items), and process work (eg: working on an assembly line or a supermarket checkout).

Repetitive stress injury can also result from recreational activities that involve repetitive and/or high-intensity movements, such as practicing a musical instrument or training for a particular sport or other type of physical activity.

Specific factors or conditions that can lead to overuse injuries developing include:

  • Awkward or constricted postures
  • Repetitive movement
  • Prolonged muscle tension
  • Forceful holding or movement
  • Vibration, especially over long periods.
  • Poor design or arrangement of equipment and furniture (ergonomics)
  • Poor work practices eg: poor time management, poor work techniques, lack of training
  • Psychosocial factors eg: excessive workload, tight deadlines, an uninspiring social and work environment.

Starting a new physical activity or intensifying a current training routine can increase the risk of an overuse injury. This is usually due to training errors (eg: too much activity too quickly) and/or technique errors (eg: poor form when doing strength training exercise or swinging a tennis racket).

Certain things are thought to increase the risk of repetitive stress injury, including:

  • repetitive activities
  • doing a high-intensity activity for a long time without rest
  • poor posture or activities that involve working in an awkward position

Cold temperatures and vibrating equipment are also thought to increase the risk of getting repetitive stress injury and can make the symptoms worse. Stress can also be a contributing factor.

Jobs that involve repetitive movements can lead to repetitive stress injury, such as working on an assembly line, at a supermarket checkout or on a computer.

Your work environment should be as comfortable as possible. You should ideally have a workplace assessment so that any adjustments needed can be made.

Your employer has a legal duty to try to prevent work-related repetitive stress injury and ensure anyone who already has the condition doesn’t get any worse.

Repetitive stress injury high-risk jobs

Any manual task that requires fast and repetitive movements or working in fixed or awkward postures for long periods of time can trigger repetitive stress injury. Anyone who works with their hands, such as hairdressers, musicians and mail workers, can experience repetitive stress injury.

Occupations at risk include:

  • office work – such as typing and clerical duties
  • process work – such as assembly line and packing
  • piece work – such as sewing
  • manual work – such as bricklaying and carpentry.

Risk factors in developing repetitive stress injury

Workplace design and work practices can contribute to repetitive strain injury. Risk factors can include:

  • furniture, tools or equipment that don’t conform comfortably to the body
  • benches or workstations that are too high, too low or too far from the body
  • machinery that operates too quickly for user comfort, such as speedy conveyor belts that force the worker to move fast
  • workspace design that requires repeated bending, stretching or twisting
  • tight deadlines that prevent workers from taking sufficient breaks
  • repetitive manual tasks.

Although an overuse injury can happen to anyone, you may be more prone to this type of injury if you have certain medical conditions. Repetitive strain injuries are also more likely to occur as you get older — especially if you don’t recognize the impact aging can have on your body and modify your routine accordingly.

For these reasons, it’s a good idea to talk to your doctor before starting a new activity or ramping up your current routine. Your doctor may offer tips to help make physical activity safer for you. If you have a muscle weakness in your hip, for example, your doctor may show you exercises to address the problem and prevent knee pain.

Repetitive stress injury prevention

Making changes to the design of a workplace and workplace practices, and using adjustable furniture can reduce the risk of repetitive strain injury.

Changes to workplace design

Suggestions include:

  • Use ergonomically designed furniture and equipment.
  • Rearrange the workspace to keep everything needed within easy reach.
  • Keep benches at waist height, so that shoulders can relax and arms can bend gently at the elbows.

Changes to work practices

Suggestions include:

  • Schedule work to include frequent breaks.
  • Vary tasks so that repetitive hand movements are alternated with other work.
  • Set realistic deadlines.

Adjusting furniture to suit your body

Keyboard operators and typists are commonly at risk of developing repetitive strain injury. Furniture, such as chairs and desks, should be adjusted to suit the dimensions of the individual and support good posture.

Suggestions include:

  • Adjust the height of your chair until your elbows are level with the keyboard.
  • Use a chair with a lumbar (lower back) support.
  • Keep document holders next to the computer screen, at the same viewing distance.
  • Use a footstool to raise the level of your knees slightly higher than your hips, if you cannot make adjustments to your desk and chair.
  • Locate the mouse close to the keyboard and use a mouse pad.
  • When possible use regular-sized computers instead of smaller laptops.

Most overuse injuries are avoidable. To prevent an repetitive strain injury:

  • Regular stretching and strengthening exercises for your sport, fitness or work activity, as part of an overall physical conditioning program, can help to minimize your risk of muscle strains. Try to be in shape to play your sport; don’t play your sport to get in shape. If you have a physically demanding occupation, regular conditioning can help prevent injuries.
  • Use proper form and gear. Whether you’re starting a new activity or you’ve been playing a sport for a long time, consider taking lessons. Using the correct technique is crucial to preventing overuse injuries. Also make sure you wear proper shoes for the activity. Consider replacing your shoes for every 250 to 500 miles you walk or run — or at least twice a year if you regularly exercise.
  • Pace yourself. If you’re starting a new fitness program, avoid becoming a weekend warrior. Compressing your physical activity for the week into two days can lead to an overuse injury. Instead, aim for at least 30 minutes of moderate physical activity a day. If you don’t have time for a full 30 minutes, you can break it down into smaller blocks of activity throughout the day. It’s also a good idea to take time to warm up before physical activity and cool down afterward.
  • Gradually increase your activity level. When changing the intensity or duration of a physical activity, do so gradually. For example, if you want to increase the amount of weight you’re using while strength training, increase it by no more than 10 percent each week until you reach your new goal.
  • Mix up your routine with cross-training. Instead of focusing on one type of exercise, build variety into your fitness program. Incorporating a variety of low-impact activities — such as walking, biking, swimming and water jogging — can help prevent overuse injuries by allowing your body to use different muscle groups and not overload any one particular group.

And be sure to include strength training for the major muscle groups in your arms, legs and core at least twice a week.

Repetitive stress injury symptoms

Repetitive stress injury symptoms vary, depending on the individual, the site of injury and the severity of the condition. At the beginning, your arms and hands will just feel tired and fatigued, which you may think is normal. Then, you may begin to feel musculoskeletal pain, meaning pain in your muscles, bones, ligaments, tendons and nerves. If it continues to get worse, you could be dealing with microtrauma, which occurs when small parts of your soft tissue begin to tear. Eventually, your muscles and tissues will experience more and more trauma, resulting in pain and loss of use.

The symptoms of repetitive stress injury can range from mild to severe and usually develop gradually. They often include:

  • pain, aching or tenderness
  • stiffness
  • throbbing
  • tingling or numbness
  • muscle weakness
  • swelling
  • restricted mobility of the joint
  • cramp
  • gradual loss of the ability to move your hands and/or arms like you once could.

At first, you might only notice symptoms when you’re carrying out a particular repetitive action.

Tenderness and guarding are often present in overuse injury. Other signs and symptoms may include a history of popping, clicking, rubbing, erythema, or vascular phenomena 1.

It is not possible to ‘work through’ cumulative trauma disorder. Initially the pain and stiffness may be slight and only noticeable while the particular manual task is performed. If these symptoms are ignored the discomfort will escalate until the joints, muscles and tendons are painful even when at rest.

But without treatment, the symptoms of repetitive stress injury may eventually become constant and cause longer periods of pain. You may also get swelling in the affected area, which can last for several months.

Repetitive stress injury diagnosis

Repetitive strain injury (RSI) may be diagnosed when symptoms develop after a repetitive task and fade when the task is stopped.

Your doctor will examine the area where you have pain and ask about your symptoms and medical history. During the physical exam, your doctor will check for swelling, points of tenderness and passive and active range of motion (ROM). The location and intensity of your pain can help determine the extent and nature of the damage. Tenderness and guarding are often present. Crepitus, either painful or painless, is often found during the ROM examination. Obvious erythema (redness), swelling, and anatomic derangement raise the possibility of an acute injury or infection, as well as the presence of an inflammatory disease 2.

In more severe injuries, where the muscle or tendon has been completely ruptured, your doctor may be able to see or feel a defect in the area of injury. Ultrasound often can help distinguish among several different types of soft tissue injuries.

If your symptoms suggest you have swollen and inflamed tissue, you may have an underlying medical condition, such as:

  • Bursitis – inflammation and swelling of the fluid-filled sac near a joint, such as the elbow or shoulder
  • Nerve entrapment, such as carpal tunnel syndrome
  • Dupuytren’s contracture – a thickening of the tissues in the hand, which causes one or more fingers to bend into the palm
  • Epicondylitis – inflammation of the area where bone and tendon join, such as the elbow
  • Rotator cuff syndrome – inflammation of the tendons and muscles around the shoulder
  • Tendonitis – inflammation of a tendon
  • Tenosynovitis – inflammation of the sheath that covers the tendons, most commonly in the hand, wrist or forearms
  • Trigger finger – where swelling in a tendon running along one of the fingers makes it difficult to either bend or straighten the affected finger
  • Ganglion cyst – a sac of fluid that forms around a joint or tendon, usually on the wrist or fingers
  • Raynaud’s phenomenon – a condition where the blood supply to extremities such as the fingers is interrupted, especially when exposed to cold
  • Thoracic outlet syndrome – compression of the nerves or blood vessels that run between the base of the neck and the armpit
  • Writer’s cramp (a type of dystonia) – a condition caused by overuse of the hands and arms

If your symptoms don’t immediately suggest one of the above conditions, you may be referred for further tests.

For example, you may be given an X-ray to test for osteoarthritis, or blood tests to rule out inflammatory joint conditions.

If no other condition is found after having tests, you may be diagnosed with “non-specific upper limb pain syndrome”.

Imaging studies

The diagnosis of most repetitive stress injuries does not require imaging studies. However, if surgical intervention is considered, imaging studies are vital for the decision-making process.

Radiography

Bony avulsions are relatively common among people who participate in dance, athletic activity, and heavy physical labor. Radiography is useful for defining these bony avulsions.

Stress fractures; calcification of tendons, which occurs in persons with chronic tendonitis; joint mice; myositis ossificans; heterotopic ossification; and atrophy of cartilage generally are revealed with radiography.

Bone scanning

This may reveal stress fractures that are not evident on radiographs.

Magnetic resonance imaging (MRI)

Typically, MRI is more effective for acute injuries; findings are generally more subtle with chronic injuries.

MRI is increasingly effective for revealing the site of nerve compression when large nerves are involved (eg, ulnar, median, sciatic), but it is not yet definitive for smaller nerves. Its true sensitivity is still being determined for these uses.

MRI has been quite successful in revealing tendon, ligament, and muscle injuries. It is easily available, does not involve radiation, and can help to assess chronicity of soft-tissue injuries.

The presence of bone marrow edema on MRI scans may precede visualization of stress fractures of the cortical bone and indicates trauma to the trabecular portions of the bone.

Banks and colleagues 3 published a review of MRI findings in athletes’ overuse injuries.

Ultrasonography

In the hands of a skilled clinician, ultrasound can be a quick and effective method in the clinic to assess for fluid collections, impingements, and/or soft tissue tears associated with many overuse injuries. However, ultrasound typically is not utilized as much in the surgical planning process as the aforementioned imaging modalities.

Laboratory studies

Laboratory tests are rarely contributory to the evaluation of overuse injury, and no laboratory results contribute to the diagnosis of overuse injury. However, several tests are generally ordered during the initial workup to rule out other etiologies of pain, depending on the patient’s presentation, including, but not limited to, the following:

  • Erythrocyte sedimentation rate (ESR)
  • Rapid plasma reagent testing (RPR)
  • Antinuclear antibody testing (ANA)
  • C-reactive protein (CRP)
  • Complete blood count (CBC)
  • Vitamin B12
  • Thyroid-stimulating hormone (TSH)
  • Comprehensive metabolic panel (CMP)

Electrodiagnostic testing

Electrodiagnostic testing (eg, electromyography (EMG), nerve conduction studies) can be very useful when employed in the appropriate scenarios. In cases of peripheral nerve compression or injury, such testing can provide evidence of the location and severity of the injury. Electromyography (EMG) and nerve conduction studies are not tests with high specificity, although they can provide much-needed information when vague symptoms are the chief complaint. They are also very useful for documenting work-related injuries.

Repetitive stress injury treatment

The first step in treating repetitive stress injury is usually to identify, modify or avoid the task or activity that is causing the symptoms. If necessary, you may need to stop doing the activity altogether. Using the involved area in nonpainful ways often helps to maintain range of motion (ROM). Total bed rest is virtually never advisable for these patients. Participation in a carefully planned physical therapy program is important for the following reasons:

  • Patient education
  • Supervised use of the injured part 4
  • Appropriate use of modalities (eg, transcutaneous electrical nerve stimulation units, similar electrical treatments, ultrasound/phonophoresis, iontophoresis, heat/cold)
  • Development of a home exercise program
  • Psychosocial benefits related to frequent interaction with an active partner in the treatment regimen

Possible treatment options for repetitive stress injury include:

  • medication – including paracetamol, short-term use of anti-inflammatory medicines, such as ibuprofen, or pain receptor-blocking medications, such as some forms of antidepressants, if you’re getting severe symptoms or interrupted sleep
  • cold packs, elastic supports or a splint
  • physiotherapy – including advice on posture and stretches or exercises to help strengthen or relax your muscles
  • steroid injections to reduce inflammation in an affected area (these are only recommended if an area has definite inflammation caused by a specific condition, such as carpal tunnel syndrome)
  • surgery to correct specific problems with nerves or tendons (for example, if you are diagnosed with carpal tunnel syndrome or Dupuytren’s contracture) if other treatments haven’t helped

To relieve symptoms, your doctor may recommend taking acetaminophen (paracetamol) or a short course of a non-steroidal anti-inflammatory drug (NSAID), such as ibuprofen. They may also suggest using a hot or cold pack, elastic support or splint.

You may also be referred to a physiotherapist for advice on posture and how to strengthen or relax your muscles. Some people find that other types of therapy help to relieve symptoms, including massage, yoga and osteopathy.

If you have a specific medical condition, well-established treatments can often be recommended. These include self-help measures, medication, or even surgery, in some cases.

Some of these treatments may help even if a specific medical condition can’t be diagnosed from your symptoms. However, in these cases, their effectiveness may be limited.

Repetitive strain injury physical therapy

Many people who have repetitive stress injury for a long time try other types of complementary therapies and relaxation techniques to help relieve their symptoms, such as:

  • yoga
  • acupuncture
  • the Alexander technique

However, while some people with repetitive stress injury find these helpful, there’s little scientific evidence to suggest they’re consistently effective for repetitive stress injury.

Occupational therapy

Occupational therapists with experience in this field can help to identify workplace modifications. In cases of individuals with disabilities who develop overuse injuries as a result of the interface with adaptive equipment, occupational therapy may be of great benefit. Often, simple modifications in the manner in which the patient performs activities of daily living or modifications in the equipment itself confer relief.

Vocational rehabilitation and work-hardening programs are often effective for bringing motivated patients back into the workforce. Integration of this type of program has proven to be effective in the corporate world and has decreased the overall financial impact of overuse injuries in the workplace.

Workplace health

If your repetitive stress injury is caused by repetitive activity at work, the first step is to speak to your employer or occupational health representative. It may be possible to modify your tasks to relieve the symptoms. Small changes to your lifestyle and working environment can often help.

Think about your working environment and what activity may be causing the problem. Take steps to reduce how much time you spend doing this activity or change how you do it.

If you can’t stop doing it completely, take regular, short breaks to stretch and move about. Software packages that remind you to take regular breaks from the keyboard can be useful.

It can also be helpful to get advice from an occupational health representative at work on how to set up your work station.

Exercise

Some people with symptoms of repetitive stress injury find that including exercise in their daily routine, such as walking or swimming, also eases their symptoms.

Medical therapy

Injection of involved structures with combinations of corticosteroids and local anesthetics is frequently quite helpful in persons with overuse injuries. Pain relief enables more effective participation in therapy, and it may help to limit the likelihood that the patient will develop a chronic pain syndrome. In most cases, injections should be performed after less invasive measures fail.

Steroid injections are the most commonly used procedure in the treatment of overuse injuries, although controversy surrounding this treatment is still readily apparent. Tendons and ligaments can become structurally weakened by the use of steroids, predisposing them to rupture. The use of local anesthetics and steroids should be reserved for patients with significant pain who have the ability to change the underlying cause behind their injury. Repeatedly injecting patients who will inevitably return to the same routine that initially caused the injury is not advisable 5.

Many steroid injections can be performed under ultrasonographic guidance to increase accuracy and decrease the possibility of intratendon or intraligament injection.

Rarely, immediate relief of pain may be necessary to allow participation in an athletic or performing arts event, and this can be achieved through injection therapy.

Surgical intervention

Surgical intervention is undertaken if conservative approaches fail and if the injury is amenable to surgery. Decompression of nerves and repair of lax or failed ligaments are the most common overuse injuries that lead to surgery. Surgeries that are performed solely to relieve pain in the absence of objective findings are notorious for suboptimal outcomes.

You will likely have a physical or occupational therapist who can help you recover after the surgery. They’ll teach you some different range of motion exercises that will help you regain normal functionality in either your hand or arms.

When you’re ready, you can start performing strengthening exercises to further improve how your hand and/or arm functions.

Repetitive stress injury prognosis

Most overuse injuries resolve after 3-6 months. However, unless the offending causes are addressed, recurrences are quite common. Patient motivation and commitment to prevention are key to rehabilitating repetitive stress injuries. Making a small, but significant, lifestyle change, and incorporating helpful stretching exercises, will help relieve pain in your hands and arms and prevent another nagging injury.

Home exercise programs tailored to the individual’s biomechanics are another important facet of treatment.

But if you don’t seek treatment for overuse syndrome, it can lead to permanent injuries, sometimes so severe that you completely lose functionality in the affected area.

Recovery after surgery varies depending on the procedure.

References
  1. Pritchard MH, Pugh N, Wright I, et al. A vascular basis for repetitive strain injury. Rheumatology (Oxford). 1999 Jul. 38(7):636-9.
  2. Battery L, Maffulli N. Inflammation in overuse tendon injuries. Sports Med Arthrosc. 2011 Sep. 19(3):213-7.
  3. Banks KP, Ly JQ, Beall DP, et al. Overuse injuries of the upper extremity in the competitive athlete: magnetic resonance imaging findings associated with repetitive trauma. Curr Probl Diagn Radiol. 2005 Jul-Aug. 34(4):127-42.
  4. Meltzer KR, Standley PR. Modeled repetitive motion strain and indirect osteopathic manipulative techniques in regulation of human fibroblast proliferation and interleukin secretion. J Am Osteopath Assoc. 2007 Dec. 107(12):527-36.
  5. Cartwright MS, White DL, Demar S, Wiesler ER, Sarlikiotis T, Chloros GD, et al. Median nerve changes following steroid injection for carpal tunnel syndrome. Muscle Nerve. 2011 Jul. 44(1):25-9.
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