Repetitive strain injury in its chronic form can be totally crippling and debilitating. It affects the central nervous system, causing pain, weakness and fatigue. It is vital that interpreters reduce the risk of RSI by adopting good working practices and by taking note of any warning signs.
Repetitive strain injury is caused by three main factors:
- Static muscle loading - holding muscles that are designed for movement, such as those in the upper arms, in static or contracted position. In sign language interpreting static muscle loading occurs in the neck, shoulders, upper back and the upper arms. The effect is to significantly reduce the circulation of blood through the muscles. This, in turn, causes a reduction of oxygen and a build up of waste products in the affected muscles leading to muscle fatigue.
- Overuse - repetition of movement in specific muscle groups; tendons, joints and nerves. Much depends on the task performed but overuse may cause a localised injury. The risk areas for interpreters are the forearms, wrists and hands.
- Stress - caused by pressure or pace of work. As the pace is set by the speaker it does not allow sign language interpreters to control his/her own work rate. This can increase stress levels, giving rise to greater muscle tension and generally reducing the body’s tolerance.
If sign language interpreters sit whilst working, there is a greater inclination for static muscle loading. Standing incorporates more full body movements, assisting circulation and reducing the risk of upper limb disorders. It also allows for extension of the elbow, which can be restricted if sitting. Increasing the elbow angle will slow circulation to the lower arm and increase the likelihood of nerve irritation at the elbow and lower arm injuries.
As it is not always appropriate or convenient to stand when interpreting, correct posture when seated is vital if injury is to be prevented. The body should be in an optimal position to allow the blood to flow freely, and the joints to be in a neutral position - not bent or over-stretched. Crossing the legs should be avoided as the compression on the lower leg decreases the blood supply and the back will be slightly twisted, giving rise to tension through the spine. If possible, the interpreter should use a chair that is at the right height and adjusted to support the spine. It is important to remember that the circulatory system and the nervous system are interlinked and spread throughout the entire body - it is necessary therefore to consider the whole body and not just the areas at risk.
- Stretching exercises can help to reduce the risk of RSI
Interpreters need to relax their arms and shoulders and fingers and hands should not be clenched. When taking a break, interpreters should concentrate on relaxing all joints, particularly the shoulders, elbows, hands and fingers. Learning some practice stretches could also be beneficial. They take minimal time to complete yet allow the body to perform to an optimum capacity all day.