Last Updated on November 16, 2023
Repetitive strain injury also called repetitive stress injury is an umbrella term for conditions where symptoms develop due to the build-up of damage over the period, owing to repetitive motion.
The term includes a lot of disorders which could be occupational, recreational, and habitual activities.
Bernardino Ramazzini, in 1700 was the first person to describe repetitive strain injury.
The condition can affect any part of the body but shoulder, elbow, wrist and hand are most commonly involved. An RSI can affect almost any movable part of the human body. RSIs are associated with repetitive tasks, forceful exertions, vibrations, mechanical compression, and sustained or awkward positions.
A repetitive strain injury is also known as cumulative trauma disorder because the tissue damage gets added from repetitive demands over the course of time.
Other names for repetitive strain injury are
- Repetitive stress injury
- Repetitive motion disorder/injuries
- Cumulative trauma disorder
- Overuse syndrome
- Regional musculoskeletal disorder
The recent surge of gadgets has led to a rise in RSIs.
Examples of Repetitive Motions
Humans perform quite a variety of repetitive motions but the following are examples of the motions responsible for the majority of the cases.
Manual labor, office work, and tech devices are mainly responsible for these conditions. A recent tsunami of available gadgets and overuse for work or entertainment is responsible for rise in related RSIs.
A few common examples of repetitive motions are
- Grasping tools, especially the vibrational tools
- Working in an assembly line
- Rigorous sports training
- Continuous mouse use
- Playing games
- Gaming console
- PC
- Smartphone
- Tablet
Previous injuries or conditions of wrist, back, or shoulder, can also predispose the person.
Examples of repetitive strain injury are
- Tendinosis
- Carpal Tunnel syndrome
- De Quervain syndrome
- Thoracic outlet syndrome
- Tennis elbow
- Golfer’s elbow
- iPod finger
- PlayStation thumb
- Rubik’s wrist or Cuber’s thumb
- Stylus finger
- Emacs pinky.
Causes of Repetitive Strain Injury
The main cause of the injury is repetitive use of the muscle. So any activity or task that has a repetitive nature may increase the risk of having an injury.
Following is a common list
- Use of vibrational tools
- Poor posture
- Forceful exertions
- Carrying heavy loads
- Stress
- Mechanical compression
- Sustained or awkward positions.
- Reading books while looking down
- Use of phone/mobile leaning onto one side
- Watching TV in incorrect position e.g. Too much to the left/right.
- Sleeping with head forward, while traveling
- Specialized cyclical labor activity Cyclical activity due to labor specialization
Pathophysiology of Repetitive Strain Injury
The basic cause is an accumulation of tissue stress because tissues do not get enough time to relax. This leads to mechanical fatigue which is followed by injury.
Thus, put simply, the rate of injury simply exceeds the rate of adaptation and healing in the tissue.
Ischemic injuries to nerves have been suggested as a possible reason.
Continuous activation of low-threshold motor units that occurs in muscles performing repetitive tasks is thought to be another reason.
Altered levels of prostaglandin E2 and nitric oxide have been found at the site of injury.
However, the precise reason for the condition is not clear.
Clinical Presentation (Symptoms and Signs)
The exact symptoms of overuse injury or repetitive strain injury would depend on the region involved and the forces involved. These conditions have been discussed separately in detail. In this article, we will stick to the general nature of the presentation of repetitive strain injury.
The often involved regions are the arm, back, shoulders, wrists, hands, or thumbs that worsen with activity.
Sports-related injuries involve the lower limb.
- Pain: The major complaint usually is pain followed by stiffness in the involved muscle or region. Initially, the pain is intermittent and worsens with activity but it later becomes of constant nature.
- Inability to Perform Task: The patient may complain of weakness and lack of endurance. In occupational injuries, the work or output of the person may be affected.
- Tenderness: The physical examination may reveal the tenderness of the region. Simulation of activity may mimic the pain.
- Swelling: It may be present in some cases but many people do not have any swelling.
- Stiffness: True stiffness may not be there but the patient can guard against the pain by reducing the movements
Diagnostic Work-up
The lab work is often normal. So are X-rays and other images.
Nerve conduction studies and electromyography can reveal the peripheral nerve compression or injury to know about the location and severity of the injury.
Treatment of Repetitive Strain Injury
- Activity Restriction/Modification: Resting the affected part provides enough time to repair itself. The rest can be provided by partial or complete avoidance of the activity. In some cases, activity modification helps.
- RICE: Rest, ice, compression, and elevation
- Splints: Splints can be applied when feasible and can help in restriction of the activity.
- Local Heat or Cold: Applying heat or cold over the painful area is known to soothe.
- Drugs: Pain relief and anti-inflammatory drugs like NSAIDs [Ibuprofen, aceclofenac, etc] are the commonly prescribed drugs. Muscle relaxants can be used as adjuncts. Corticosteroids and antidepressants are useful in certain cases.
- Steroid Injections: Sterois heal the inflammation by their antiinflammatory action.Steroid injections under ultrasonographic control increase accuracy and decrease the possibility.
- Physical Therapy: Physical therapy can aid in early recovery. There are many modalities that can be used-
- Supervised use of the injured part
- Transcutaneous electrical nerve stimulation or TENS
- Ultrasound therapy
- Iontophoresis [technique that applies current on the surface ]
- Heat/cold application
- Proper training and equipment to prevent further injury
- Exercises: Exercises are prescribed as part of physical therapy. The recent trend is not to provide rest and start the exercise straightway.
- Relaxation: Relaxation helps to reduce stress and its effects on pain. Meditation, breathing techniques, or any method can be used.
- Surgery: Surgical intervention is undertaken if conservative approaches fail and if the injury is amenable to surgery. The surgery usually involves the decompression of nerves and the repair of lax or failed ligaments.
Prevention of Repetitive Strain Injury
Because repetitive strain injury is caused by repeated activity, the key to prevention is to break the repetition by taking frequent breaks.
Reduction of the intensity of the activity also can be done.
The following measures are aimed at both – taking breaks as well as reducing of intensity of the activity.
- Take frequent breaks
- For example in computer or typing work- look frequently away from the screen for relaxing eyes
- Change of posture – Standing up and stretching to avoid continuous sitting
- Maintain good general health
- Healthy eating
- Regular exercise- better muscle endurance
- Quit smoking – Increases blood flow and reparative capacity
- Stress management techniques and coping skills
- Better equipment and terrain training for sports
Avoiding Repetitive Strain Injury in Desk Job
- Ergonomic chair, desk, and screen
- Avoid slouching
- Keep an erect posture
- Do not bend your wrists while typing
- Do not hit the keyboard with force
- Do not grip the mouse too tightly
- Wear a headset for a phone conversation, if calling is part of the job
Prognosis
Most individuals respond well to the treatment and show complete recovery. Most repetitive strain injuries resolve after 3-6 months.
Recurrence is common when the offending cause is not removed.
Recovery after surgery varies with the procedure.
