Spasticity refers to feelings of stiffness and a wide range of involuntary muscle spasms (sustained muscle contractions or sudden movements). It is one of the more common symptoms of MS. Spasticity may be as mild as the feeling of tightness of muscles or may be so severe as to produce painful, uncontrollable spasms of extremities, usually of the legs. Spasticity may also produce feelings of pain or tightness in and around joints, and can cause low back pain. Although spasticity can occur in any limb, it is much more common in the legs.
- In flexor spasticity the muscles are so tight that the limbs are bent and difficult to straighten.
- In extensor spasticity the muscles are so tight that the limbs remain straight and are difficult to bend.
Spasticity may be aggravated by sudden movements or position changes, extremes of temperature, humidity or infections, and can even be triggered by tight clothing.
Some degree of spasticity can provide benefit, particularly for people who experience significant leg weakness. The spasticity gives their legs some rigidity, making it easier for them to stand, transfer, or walk. The goal of treatment for these individuals is to relieve the spasticity sufficiently to ensure comfort and prevent complications, without taking away the rigidity they need to function.
Spasticity and muscle tightness is commonly treated with medications, physical and occupational therapy. Because spasticity varies so much from person to person, it must be treated on an individual basis and demands a true partnership between the person with MS and his or her healthcare team (e.g. physician, nurse, physician assistant, physical therapist and occupational therapist). Left untreated, spasticity can lead to serious complications, including contractures (frozen or immobilized joints) and pressure sores
. Since these complications also act as spasticity triggers, they can set off a dangerous escalation of symptoms.