A repetitive strain injury (RSI) (or repetitive stress injury) is caused by gradual damage to a body part over time. Affected body parts may include muscles, tendons, ligaments and even nerves.
Repeating particular tasks or holding awkward or unusual positions can cause an RSI. So can forceful exertions, vibrations or mechanical compression if repeated over time.
RSIs are also known as overuse injuries, repetitive motion injuries and cumulative trauma disorder, just to name a few alternative terms. Many RSIs are also sports injuries that typically affect athletes (e.g. shin splints or lower leg stress fractures).
Whatever the name, RSIs take place over extended periods and can affect just about any movable part of your body. They have been around since humans have been performing manual labour. However, the main RSI causes in the modern world are not only manual labor but office work and technological devices e.g. computers.
RSI symptoms include pain, stiffness and tenderness in the injured area, among other problems. Treatment usually involves some or all of the steps of the P.R.I.C.E. (Protection, Rest, Icing, Compression and Elevation) protocol. In rare circumstances, corrective surgery is required.
The term RSI refers to a multitude of different injuries that all have one common factor – that of occurring over time. Hence, the specific causes of each RSI are different.
However, many RSIs are due to the cumulative effect of repetitive tasks that cause small stresses on a particular body part. None of these stresses is damaging in itself, but they all repeat themselves multiple times over days, weeks and months. The RSI is therefore the result of the cumulative impact of these stresses over time.
Similarly, RSIs due to uncomfortable positions, or prolonged standing, are due to the cumulative impact of this activity over time.
RSI Risk Factors
Some of the factors that can increase your risk of suffering a repetitive stress injury are:
Being in poor physical condition, or having under-developed muscles;
Having a job that requires you to perform repetitive movements on a daily basis. A few examples are gardeners or people who work with computers (typing or handling a mouse);
Working in a job that requires long hours in crouched positions (e.g. plumbers);
Having a job that requires long periods of standing (e.g. bus conductors, air hostesses or teachers);
Playing a sport that requires extensively repeated motions e.g. being a pitcher in baseball.
Symptoms Of A Repetitive Stress Injury
Because the term refers to many different underlying injuries, RSI symptoms can vary greatly from one case to another. However, speaking generally, the symptoms of an overuse injury include:
Painful muscles or joints. This pain may intensify during periods of activity or when you just try to move the affected body part ;
Joint instability (i.e. inability to bear weight without giving way) or weakness;
Muscles or joints being “tender to the touch”;
Lost range of motion of a joint;
Bruising of the skin over the injured muscle or joint;
Loss of sensation in the affected body part.
As mentioned above, the specific symptoms will depend on which body part is affected and on the severity of the injury.
In many cases, the symptoms may appear intermittently (i.e. may come and go) in the early stages of an RSI. Usually, however, they become more consistent and severe over time if the overuse injury is left untreated.
Types Of Repetitive Stress Injury
Doctors divide repeated stress injuries into two types:
A type 1 RSI involves damage to the musculoskeletal system (i.e. to muscles or tendons). Symptoms usually relate to specific muscles and tendons;
A type 2 RSI can have a wider range of causes. Most of them involve nerve damage related to occupational activity.
Diagnosis of an RSI usually involves a physical examination of the affected body part. Your doctor may also ask questions about repetitive tasks you perform using that part of your body. He or she may also inquire about when the pain is most severe or what aggravates it.
Imaging studies are usually not necessary to diagnose a repetitive stress injury. In the rare situations when they are requested, the doctor is probably trying to eliminate another possible cause of your symptoms.
Treatment Of An Overuse Injury
As mentioned above, the symptoms of each RSI can vary. As a result, the treatment plan can also vary from one case to another.
Generally, repetitive stress injuries are treated conservatively using the following R.I.C.E. protocol:
Rest the injured body part by avoiding stressful activities that could aggravate the injury. Wear an orthopedic brace or athletic tape to support injured muscles, tendons and ligaments and protect them further;
Ice the injured body part or apply a cold compress every few hours. This will reduce blood flow and pain. The reduced blood flow will reduce any swelling. Once pain and swelling have eased, switch to using a hot compress to promote blood flow;