Spasticity is a symptom of multiple sclerosis (MS) that causes involuntary muscle stiffness and spasms. MS occurs when the body’s immune system mistakenly attacks the myelin sheath, which is the protective covering around nerve cells.

About 60–84% of people living with MS experience spasticity, which affects individuals to varying degrees. It can range from being a minor annoyance to causing issues that have a significant effect on daily living and quality of life. It can manifest as muscle spasms, tightness, and pain, which influence how someone performs daily tasks.

MS develops because the immune system damages myelin, which is responsible for protecting the nerves. This damage prevents the nerves from relaying signals correctly.

This article looks at MS spasticity in more detail, including its causes and treatments.

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Spasticity is a common symptom of MS. It refers to muscle stiffness and involuntary muscle spasms, including pronounced contractions and sudden, uncontrollable movements.

Spasticity varies in its severity. Some individuals experience minor muscle tightness that has little effect on daily living. However, others may have severe spasticity that causes uncontrollable spasms of the limbs and limits the ability to walk or move objects. Uncontrollable spasms can also cause pain in and around the joints and spine.

Flexor spasticity tightens the limbs in a bent position to the extent that someone cannot straighten them. However, extensor spasticity causes the limbs to straighten and prevents an individual from bending them.

For some individuals, spasticity can cause pain and a sensation of muscle tightness. However, the signs and symptoms are highly variable and may include:

  • reduced range of motion
  • difficulty relaxing or releasing the muscles
  • clonus, which is a repetitive movement of a hand or foot
  • increased deep tendon reflexes

A person can experience powerful spasms that cause their legs and arms to jerk with significant force or fix in uncomfortable positions.

Muscle spasms and stiffness can cause pain ranging from dull aches to sharp, unbearable pain. These symptoms can also interfere with good posture, leading to back pain and other discomforts.

Stiffness can sometimes have a positive effect. For example, it can help someone with weak leg muscles walk and stand.

Spasticity in MS occurs because of damage to the myelin covering nerves that control movement. This damage causes nerve impulses to slow down or stop, resulting in neurological problems.

MS is an autoimmune disease in which the immune system mistakenly attacks the myelin sheath or the cells responsible for producing and maintaining it. This attack leads to inflammation and damages both the myelin sheath and, eventually, the nerves that it surrounds.

The word sclerosis refers to the multiple areas of scarring on the nerves and their myelin sheaths in MS.

Environmental factors, such as extreme temperatures, humidity, or tight clothing, can sometimes trigger spasticity in people with MS. Additionally, some people may find that changing position, sudden movements, or infections can worsen spasticity.

Spasticity and spasms are both symptoms of MS that can affect an individual’s quality of life.

Spasticity causes the muscles to feel stiff, tight, heavy, and difficult to move. Conversely, spasm means that the muscles suddenly contract and stiffen painfully, causing the arms or legs to kick or jerk. Often, people use the term spasticity to encompass spasms.

An MS spasticity scale called MSSS-88 captures a person’s experience of spasticity and its impact on their life. It helps doctors understand how well MS medications, physical therapy, and other treatments are working. It is a patient-reported scale that includes 88 questions.

The scale divides the 88 items into eight subscales:

  • Three cover spasticity-specific symptoms, such as muscle stiffness, pain, and muscle spasms.
  • Three cover the individual’s physical functioning, such as daily living, walking, and body movements.
  • Two cover the psychosocial impact, such as mental health and social functioning.

People can respond to each item using a scale that ranges from not feeling bothered by an issue to the issue having a significant effect on them. Someone with a total MSSS-88 score of 88 is relatively unaffected by the included symptoms. However, if a person has a score of 352, these symptoms all substantially affect them.

The eight subsections of the scale highlight the complex nature of spasticity. These scales provide valuable insights into how people experience spasticity and allow doctors to gauge how to improve their quality of life.

Doctors typically treat spasticity with a combination of medications and physical therapies. They work as part of a multidisciplinary team that includes physical therapists, occupational therapists, and nurses to address the effects of MS on the body.

The following options may help someone manage their spasticity.


Doctors may recommend medications to relax the muscles and relieve pain for some people with spasticity.

Baclofen (Lioresal) is an effective muscle relaxer that doctors prescribe for spasticity in MS. Other medication options include:


People whose symptoms do not respond to the above muscle relaxers may receive onabotulinumtoxinA (Botox), which temporarily blocks nerves and muscles following an injection into the area.

Physical therapy

A physical therapist works with the individual to create an exercise plan to treat MS spasticity. A comprehensive stretching program includes exercises that use gravity to stretch the muscles. A person often performs these in a sitting or lying position.

Passive stretching is a way to reduce spasticity. This involves moving and holding the joints in a position that stretches the affected muscles. The program may also include range-of-motion exercises to maintain joint mobility.

Aquatic exercises in a swimming pool are also valuable for reducing spasticity, as the water helps individuals move with less effort and does not place pressure on the joints.


A doctor may recommend permanently cutting nerves or tendons to relieve symptoms in severe cases.

Rhizotomy is an example of an MS surgery that a person may undergo to relieve facial pain. In this procedure, the surgeon cuts away a section of the nerve to prevent nerve pain in the head and face.

Spasticity is a common MS symptom. Individuals may experience pain, muscle contractions, stiffness, and uncontrollable movements that make everyday tasks challenging.

People living with MS have a range of options to help them manage spasticity. For example, doctors may recommend a combination of gentle muscle stretching exercises and medications.