Dystonia is an involuntary sustained muscle contraction, and there are different types of dystonia, with various causes. The most common affect only one body part, such as the neck (spasmodic torticollis) or the forearm ('writer's cramp') and are termed focal dystonias. Others will affect many different areas, and are termed generalised dystonia.
The most likely cause is an imbalance in the neurotransmitters which are chemicals that transmit messages in the brain. If the right amounts of the right neurotransmitters are not present, then the message is not switched off and the muscle continues to work, and is unable to relax. The cause for the imbalance is varied and may be due to a brain injury, or may be unknown.
A muscle that is frequently working is likely to become shortened and joints may become tight. Stretches will help to reduce this tightness and ease the pain associated with dystonia. Other muscles may need to be strengthened to help counteract the affected muscles. Posture, balance and walking may all have been affected depending on the location of the dystonia.
Botulinum toxin (Botox) is a common treatment for focal dystonias. This stops the nerve sending any messages to the muscle, and so it has to relax. Physiotherapy is very effective just after any injections to stretch out the tight muscles and joints and strengthen the weaker muscles.