Repetitive Strain Injury (RSI)



Repetitive Strain Injury is a descriptive term for an injury to the musculoskeletal and nervous systems caused by repetitive tasks, forceful exertions, mechanical compression, vibrations, or sustained and awkward positions. It is also known as Occupational Overuse Syndrome (OOS), Repetitive Motion Disorder (RMD), Cumulative Trauma Disorder (CTD), and Regional Musculoskeletal Disorder.

RSI’s can be associated with a variety of conditions caused by repetitive tasks, including:

Tendinosis: This describes the cellular degeneration of collagen within the tendons, due to overuse. This condition is thought to be caused by microtears in the connective tissue in, and around the tendon, resulting in an increase in tendon repair cells. This usually leads to reduced tensile strength, therefore increasing the chance of tendon rupture. Symptoms include pain, aches, or stiffness in the local area of the tendons, or a burning sensation that surrounds the whole joint around the affected tendon. The pain is usually worse during and after activity.

Tendinitis: An inflammation of the tendons caused by overuse. Symptoms include pain, tenderness, and swelling of the affected area, as well as sometimes causing stiffness in the nearby joints. Symptoms can last from a few days to months.

Tenosynovitis: The inflammation of the lining of the sheath that surrounds a tendon. This condition is caused by overuse and commonly affects the wrists and hands. Symptoms are the same as those for tendonitis.

Carpal tunnel syndrome: Caused by the compression of the median nerve, surrounding tissue, and the bony structures in the wrist. It is a common condition that causes pain, numbness, or burning, as well as a tingling sensation in the fingers (index, middle, or ring finger) and hands.

Epicondylitis (Golfer’s elbow/Tennis elbow): This describes the irritation of tendons where they attach to the epicondyles (bony projections at the end of long bones), such as the joint where the tendons of the forearm muscles attach. This condition commonly occurs in the lateral and medial side of the elbow region, hence the terms ‘golfer’s’ and ‘tennis’ elbow. Symptoms include pain, inflammation, and tenderness of the affected part of the body.

Bursitis: This is defined as the inflammation of a bursa (a small fluid-filled sac that forms under the skin over joints and between tendons and bones). A bursa’s purpose is to provide a surface to reduce friction between tissues, and can become inflamed through injury, repetitive movements, or chronic overuse. Symptoms include localised pain, swelling, tenderness, redness of the affected joint, and stiffness.

Ganglion cysts: These are swellings or lumps of varying sizes which are commonly found on top of a joint or covering a tendon, usually in those of the hands or wrists. The cysts contain a thick, clear fluid which serves as a lubricant for joints. A ganglion cyst occurs when this synovial fluid leaks out of a joint or tendon and forms a swelling underneath the skin around the affected area. There can either be no symptoms for a ganglion cyst, or symptoms of restricted movement and localised pain.

Reynaud’s Disease: Blood vessels in the extremities constrict when cold or stressed. With this condition, the smaller arteries that supply blood to the skin narrow, and limits blood circulation to the affected areas. This condition can be triggered by work involving vibration, such as using a jackhammer. Symptoms include: cold fingers or toes, colour changes in skin in response to cold or stress, and a numb, prickly feeling or stinging pain upon warming or stress relief.

Focal dystonia: This is a neurological condition that affects a muscle or group of muscles in a specific part of the body, causing involuntary muscular contractions and abnormal postures. An example, focal hand dystonia causes the fingers to either curl into the palm, or extend outward without control. In musicians, the condition is called Musician’s focal dystonia, and in sports athletes it’s known as the yips.

Blackberry thumb (De Quervain’s Syndrome): This is the term used to describe a type of RSI caused by the frequent and prolonged use of the thumbs while texting. It is defined as the irritation of the muscles and tendons at the base of the thumb. Symptoms include pain, aching/throbbing, and cramping in the thumbs, fingers, and wrists.

Cubital tunnel syndrome: This condition can result from repeated or prolonged pressure on the ulnar nerve in the “funny-bone” area, or for stretching this nerve for long periods of time. You are more likely to develop this condition if you: repeatedly lean on your elbow, particularly on a hard surface, or bend your elbow for sustained periods of time for example, talking on a mobile/telephone, or sleeping with your arm bent and hand tucked under your pillow. This condition also sometimes results from abnormal bone growth in the elbow from intense physical activity that increases pressure on the ulnar nerve. Baseball pitchers commonly have this problem. Symptoms include: pain and numbness in the elbow, tingling in the fingers (especially the ring and little fingers), weakness affecting the fingers (especially the ring and little fingers), decreased ability to pinch the thumb and little finger together, decreased overall grip, muscle wasting in the hand, and claw-like deformity of the hand.

Thoracic outlet syndrome: This condition occurs when the blood vessels or nerves become trapped between the collarbone and the first rib. It mainly affects people with jobs requiring heavy usage of the upper extremities against resistance. Doctors have noticed that people who perform repetitive tasks such as typing on a computer, using a jackhammer, working on an assembly line, or lifting things above their heads are more likely to develop this condition. Certain athletes such as baseball pitchers, weightlifters, and swimmers are also more likely to develop this condition. This condition can cause pain in the shoulders and neck, and numbness of the fingers. There are 3 different types of thoracic outlet syndrome, each depending on which structures are compressed. Neurogenic thoracic outlet syndrome is characterized by the compression of the brachial plexus. The brachial plexus is a network of nerves that come from the spinal cord and control muscle movement in the shoulder, arm, and hand. Symptoms of neurogenic thoracic outlet syndrome include: muscle wasting in the fleshy base of the thumb, numbness or tingling in the arms or fingers, pain or aches in the shoulders, arms, or hands, and a weakening grip in the hand. Vascular thoracic outlet syndrome is defined as when one or more of the veins or arteries under the collarbone are compressed. Symptoms of vascular thoracic outlet syndrome include: bluish discolouration of the hand, arm pain and swelling (possibly due to blood clots), blood clots in veins or arteries in the upper areas of the body, lack of colour in one or more of the fingers or the entire hand, weak or no pulse in the affected arm, cold fingers, hands, or arms, arm fatigue with activity, numbness or tingling in the fingers, weakness of the arm or neck, and a throbbing lump near the collarbone. Nonspecific-type thoracic outlet syndrome is characterized by a chronic pain in the area of the thoracic outlet that worsens with activity, but a specific cause of the pain cannot be determined.

Trigger finger: Also known as stenosing tenosynovitis, this condition occurs when one or more of the fingers becomes stuck in a bent position. The finger may straighten or bend with a snap, like that of a trigger being pulled and released. It occurs when inflammation narrows the space within the sheath that surrounds the tendon in the affected finger. People with work or hobbies that include repetitive gripping actions are more likely to develop this condition. Symptoms include: finger stiffness, particularly in the morning, a popping or clicking sensation when the finger is moved, tenderness or a bump/nodule in the palm at the base of the affected finger, the finger catching or locking in a bent position which suddenly pops straight, and finger locked in a bent position from which it is unable to straighten. This condition can affect any finger, including the thumb, more than one finger can be affected at one time, and both hands may be affected. Symptoms are usually worse in the morning, when firmly grasping an object, or when straightening the finger.

Radial tunnel syndrome: This condition is caused by increased pressure on the radial nerve, usually at the elbow, as it travels from the upper arm to the hand and wrist. This occurs when the radial nerve becomes irritated and inflamed from friction caused by the compression of muscles in the forearm. Symptoms include: fatigue, or a dull, aching pain at the top of the forearm (or the back of the hand and wrist) with use. Muscle weakness is caused by pain and not muscle denervation and so there are no symptoms of tingling and numbness associated with this condition.

Intersection syndrome: This condition can be defined as an overuse disorder of the dorsal distal forearm which appears after a long period of repeated activity using continuous flexion and extension or radial abduction. It is also known as tenosynovitis of the radial wrist extensors and is a cause of radial-sided wrist and forearm pain, often brought on by athletic or other activities involving repetitive wrist flexion and extension. It is a relatively uncommon condition which is often misdiagnosed as De Quervain’s tenosynovitis. Symptoms include: pain and swelling in the area within 7cm of the distal radius, erythema, oedema, grating, crackling, or popping sounds accompanying the flexion or extension of the wrist. This condition most commonly affects weightlifters, rowers, racket sports players, horse riders, and skiers.

Dupuytren’s contracture: Also known as Viking’s disease, this condition affects a layer of tissue that lies under the skin of the palm. Knots of tissue from under the skin, eventually forming a thick cord that can pull one or more fingers into a bent position, which cannot be straightened. It can be defined as the thickening and shortening of the palmar fascia that gradually causes clawing of the fingers as they are pulled towards the palm. Dupuytren’s contracture tends to develop and progress slowly over years and usually begins as a thickening of skin on the palm of the hand. As it progresses, the skin on the hand may become puckered or dimpled, and a lump of firm tissue may develop on the palm. In the later stages of this condition, cords of tissue from under the skin of the palm, and extend up to the fingers. As the cords tighten, the fingers are pulled in towards the palm. The pinky and ring finger are the most commonly affected, and the middle finger may also be affected. It is very rare for the thumb and index finger to become affected. This condition is not usually painful, although some itching and aching may occur. Using vibrating tools is thought to be one of the causes of this condition.

Rotator cuff syndrome: This injury is common in people whose work involves prolonged overhead activity. Examples of this include painters, carpenters, baseballers, and tennis players. It is a highly common shoulder injury that affects the group of muscles and tendons that surround the shoulder joint. Symptoms include: shoulder pain that can extend from the top of the shoulder to the elbow, a deep dull ache in the shoulder, pain when lying on affected shoulder, shoulder pain when at rest, muscle weakness or pain in the shoulder when attempting to reach or lift, pain or clicking when arm is at shoulder height or overhead, stiffness, and loss of mobility in the affected arm.

Hand dystonia (writer’s cramp): This is characterized by pain, cramping, and/or spasms of the hand due to overuse, and occurs when the affected individual attempts to perform fine motor tasks such as writing or playing an instrument. It is a task-specific focal dystonia of the hand.

Repeated use of the same movements causes inflammation and damage to the soft tissues (muscles, nerves, tendons, and tendon sheaths etc.)

RSI’s can potentially end up damaging the muscles, tendons, nerves, and joints through repeated microtrauma.

Since the widespread use of typewriters and computers in the 1970’s there has been a worldwide increase in Repetitive Strain Injuries of the arms, hands, neck, and shoulders.

The first description of RSI came from an Italian physician, Bernardino Ramazzini, in 1700 as he described more than 200 categories of RSI as he observed the industrial workers of Italy.

Today, workers in certain fields such as manual labour (trades, miners, farmers), and office workers are more at risk for RSI’s. Technological advances have also caused an abundance of Repetitive Strain Injuries such as Gamer’s thumb, Rubik’s wrist, Stylus finger, Blackberry thumb/iPhone thumb (De Quervain’s tenosynovitis), text neck, and Raver’s wrist.

RSI’s on a Muscular level:

When muscles and tendons are used, tiny tears can occur in the tissue, causing the local area to become inflamed for a short time until the body can repair the damage. Thickening and scar tissue begins to form over the torn muscle or tendon tissue, resulting in pain. The body would usually repair the damage, but without sufficient rest, more activity causes further damage and more inflammation, thickening, scar tissue, and pain. Microscopically, changes can be seen in the muscle or tendon which has been damaged by overuse. Collagen bundles which are normally tight and parallel, appear disorganised and discontinuous, and a noticeable increase in fibre diameter and fibre loosening has also been seen.

RSI’s and nerve damage:

Nerves can also be damaged by RSI’s. Nerves run through the muscles, so if the muscle health is poor, likely so is the nerve health. Damaged nerves have the ability to heal, but the process is extremely slow. Most cases of chronic and persistent RSI’s originate in the nerves that run down from the neck, through the shoulders, and into the wrists and hands. If the discs and muscles in the neck become damaged or tight, then the nerves in the arm cannot move freely. If these tight nerves are then used repeatedly, in processes such as typing, or texting, they become painful and inflamed. Without sufficient rest and time for the body to repair, the problem will worsen, causing difficulty in everyday tasks.

As there are so many nerve fibres that exit from the neck and into the arms, symptoms and vary widely and pain can be felt almost anywhere, therefore nenerve-relatedain is often misdiagnosed.



• Burning, aching, or shooting pain
• Tremors
• Clumsiness
• Numbness
• Tingling in the fingers
• Stiffness and swelling
• Fatigue or lack of strength
• Tenderness and pain in the affected area or joint
• Throbbing or pulsating in the affected area
• Loss of sensation
• Weakness in the hands and/or forearms, often resulting in inability to perform simple tasks
• Chronically cold hands, particularly the fingers/fingertips
• Difficulty with normal activities such as opening doors, or turning on taps
• Soreness, tingling, or discomfort in the neck, arms, wrists, fingers, or shoulders

Symptoms may appear when the individual performs a repetitive task, and may disappear when they stop the aggravating activity. It may take only a few hours for the symptoms to settle, or up to a couple of days. Over time, without sufficient rest and recovery, minor RSI’s have been known to turn into chronic injuries.



Repetitive Strain Injuries can be caused by many factors. These include:
• Use of equipment that doesn’t fit properly
• Overuse of a particular muscle or group of muscles
• Vibrating equipment
• Overexertion
• Poor posture
• Direct pressure to particular areas
• Carrying heavy loads
• Fatigue
• Forceful activities
• Working at a fast pace
• Not having enough recovery breaks
• Holding your muscles in the same position for an extended amount of time
• Lack of training in the safest way to carry out a task
• Working in cold conditions
• Lack of variety in the type of work done



A doctor will usually be able to diagnose an RSI through a physical examination and by asking questions about the sorts of repetitive tasks the individual regularly carries out, what causes discomfort, and when it tends to happen.

There are 2 broad types of RSI.

Type 1 is a musculoskeletal disorder, with symptoms usually including the swelling and inflammation of specific tendons or muscles.

Type 2 has a range of causes and is often related to nerve damage resulting from work activities. A type 2 RSI will have no additional symptoms, just a general feeling of pain and discomfort. It is sometimes known as or referred to as non-specific pain syndrome.

Blood tests are done to rule out inflammatory joint disease.



While it is relatively easy to diagnose and treat RSI’s successfully, it is difficult to cure chronic RSI.

Commonly used treatments for RSI’s include:
• Medication: Such as anti-inflammatory painkillers (aspirin or ibuprofen), and muscle relaxants. Sleeping tablets may be prescribed if sleep is affected.
• Cold or Heat treatment: Applying cold packs or heat packs may be an effective way to treat the pain and reduce the swelling associated with RSI’s.
• Splints: Elastic supports or splints are often beneficial as they prevent movement of the damaged tendons or muscles and therefore aid in healing the affected area.
• Physical Therapy: This includes exercises, manual therapy, bracing and splinting, and advice on adapting activities to cope and prevent worsening the injury. Exercises are often focused on gently strengthening the affected area and the surrounding areas so as to reduce the risk of recurring injury.
• Steroid injections: These injections are only advised if there is inflammation associated with a specific medical condition, as they can have moderate to severe side effects.
• Surgery: Used as a last resort, surgery can improve and correct problems with specific tendons and nerves.



The main way to reduce the risk of an RSI is to stop or reduce the intensity of the activity. If this is not possible, other options for reducing the risks of an RSI include:
• Taking frequent breaks, particularly if you feel tired or feel any kind of strain.
• Standing up, stretching, and taking short walks frequently throughout the day, especially if you are in an office job, or sitting a lot.
• Eye break: This is particularly important if you spend a lot of your time looking at a screen, or doing a lot of reading. Repetitive eye strain can be avoided by regularly looking up and staring for a moment at objects in the distance.
• General health: Eat healthily and exercise regularly to keep your body in good health as you are less likely to develop injuries. Avoid smoking as well as it reduces blood flow.
• When sitting in an office, ensure the desk, chair and screen are aligned in an ergonomic fashion. Avoid slouching and ensure that your ears and back are in a straight line with the pelvis. Certain aids can be bought to promote good posture.
• When typing, avoid bending the wrists too much and that the fingers, wrists, and arms are in alignment. Also, avoid hitting the keys too hard when typing.