Spasticity in Multiple Sclerosis: Symptoms, Triggers and Treatment Options

Spasticity is a common movement problem in multiple sclerosis, but it does not feel or behave the same for everyone. One person may notice a stiff ankle only after a long walk; another may have painful leg spasms, disturbed sleep or difficulty with transfers and personal care. The most useful approach is to identify what has changed, look for reversible triggers and choose treatment around a specific goal rather than trying to remove all muscle tone.

A physical therapist discusses mobility and leg spasticity with a woman living with multiple sclerosis

Key takeaways

MS-related spasticity may cause stiffness, spasms, clonus, pain and restricted movement, but weakness, fatigue, sensory change and joint stiffness can produce similar difficulties.
A sudden increase should prompt a check for infection, bladder or bowel problems, pain, skin pressure, poor positioning and other triggers.
Treatment is goal-based. Some tone may help a person stand or transfer, so reducing it too far can occasionally make function worse.
Physiotherapy, occupational therapy, exercise, positioning and self-management are often combined with medication or focal treatment.
New neurological symptoms, especially when they persist or progress, need clinical assessment rather than being assumed to be “just spasticity.”

Why does spasticity occur in multiple sclerosis?

Multiple sclerosis can damage myelin and nerve pathways in the brain and spinal cord. When pathways that normally regulate muscle activity are disrupted, stretch reflexes may become overactive. A muscle can then resist movement more strongly when it is moved quickly. This velocity-dependent resistance is one defining feature of spasticity.

Spasticity is only one part of the upper motor neuron syndrome. MS can also cause weakness, slowed movement, poor selective control, tremor, ataxia, altered sensation and fatigue. A leg that feels “heavy and stiff” may therefore reflect several problems at once. Treating muscle overactivity alone will not necessarily correct weakness, poor balance or reduced endurance.

Symptoms may fluctuate over a day and across the course of MS. They can be influenced by posture, activity, temperature, pain, sleep and other health problems. This variability is one reason that a brief examination in a clinic should be combined with the person’s account of what happens at home, at work and during mobility.

What can MS-related spasticity feel like?

People often describe tightness, pulling, a limb that will not relax, or a sudden jump or kick. Some notice resistance only during a quick movement; others experience repeated spasms at rest. Clonus is a rhythmic series of contractions, often triggered around the ankle. Symptoms can be painless, uncomfortable or sharply painful.

Stiffness that makes it difficult to bend a knee, place the heel down or clear the foot.
Legs that straighten, cross or pull together during walking or transfers.
Sudden flexor spasms that draw the hip and knee upward.
Night-time spasms that interrupt sleep or repositioning.
Tightness in the arm or hand that affects reaching, dressing or palm hygiene.
Difficulty sitting comfortably or maintaining a stable position.
Skin pressure, pain or difficulty fitting footwear or an orthosis.

Lower-limb symptoms are common, but arms and trunk can also be affected. The impact matters more than the presence of tone alone. Mild stiffness that does not cause pain, limit movement or create a care problem may not require active reduction. Conversely, a moderate change that causes falls or prevents hygiene deserves attention.

Spasticity should also be distinguished from a fixed contracture, joint disease and other forms of abnormal tone. If a joint remains restricted during slow passive movement, read about the difference between spasticity and contracture.

Why can spasticity suddenly become worse?

An unexpected increase is often the nervous system’s response to another problem. Before increasing a medicine or stretching harder, look for a trigger that can be treated. Common examples include:

A urinary tract infection, urinary retention or an overfull bladder.
Constipation, diarrhoea or abdominal discomfort.
Pressure injury, a blister, ingrown nail, tight clothing or poorly fitting equipment.
Muscle, joint, dental or nerve pain.
Respiratory or other infection, fever and general illness.
Prolonged sitting, poor positioning or a change in wheelchair support.
Cold conditions, fatigue, emotional stress or disrupted sleep.
A recent fall, fracture or other injury.

People with reduced sensation may not feel the source clearly, so a careful skin and equipment check can be important. Treating the trigger may return spasticity to its usual level without changing long-term therapy. Our guide to sudden worsening of spasticity provides a practical sequence of checks and warning signs.

Heat deserves a separate note. A rise in body temperature can temporarily worsen many MS symptoms because already-damaged nerve pathways conduct less efficiently. This is sometimes called a pseudo-relapse. It may coexist with greater stiffness, but a new or persistent neurological change should not be attributed to heat without appropriate clinical advice.

How is spasticity assessed in MS?

Assessment begins with the problem the person is experiencing. A clinician may ask about spasms, pain, sleep, falls, walking distance, transfers, hand use, bladder and bowel symptoms, skin, medication timing and recent changes. A short symptom diary can show whether the problem is linked to a particular time, activity or trigger.

The physical examination may compare slow and faster passive movement, joint range, strength, sensation, coordination, posture and balance. The Modified Ashworth Scale records resistance during passive movement, while the Tardieu approach examines the response at different velocities. Neither score is a complete measure of function. Learn more in How Is Spasticity Measured?

Walking and transfers should be observed when relevant. The clinician may examine foot placement, knee control, hip adduction, effort and safety, and may assess the effect of a walking aid or orthosis. For the upper limb, useful outcomes might include opening the palm, reaching, stabilising an object or completing dressing. Pain should be assessed rather than automatically attributed to tone; our spasticity and pain guide explains why the source matters.

It is also important to distinguish a gradual change in a familiar symptom from a possible relapse. A relapse generally involves new or worsening neurological symptoms that persist and are not better explained by fever, infection or another cause. The person’s MS team should assess suspected relapse, especially when vision, strength, sensation, balance, bladder function or cognition changes.

Treatment starts with a specific goal

Reducing a score on an examination is not enough if daily life does not improve. Goals may include fewer painful spasms, easier sleep, safer transfers, better foot placement, easier dressing, improved hand hygiene or the ability to participate in exercise. The team should agree how success will be measured and when the plan will be reviewed.

Some people use extensor tone to remain upright, stand or transfer. A treatment that relaxes the legs may reduce pain but also reveal underlying weakness. This does not mean treatment should be avoided; it means benefits and possible losses must be discussed, and changes should be introduced carefully. A trial, a time-specific dose or a focal approach may sometimes fit the goal better than broad reduction of tone.

Treatment options for spasticity in MS

Physiotherapy, occupational therapy and movement

Rehabilitation may include supported range-of-motion work, strengthening, task practice, gait or transfer training, balance work, positioning and advice about pacing. Exercise should reflect fatigue, heat sensitivity, fall risk and the person’s wider MS symptoms. It is not necessary to avoid strengthening simply because spasticity is present. The practical aim is controlled movement that supports the chosen activity.

Stretching may improve comfort and access to the available range, but it should not be promised as a cure or forced through pain. Our guide to stretching and exercise for spasticity describes safer principles. Occupational therapy can address hand use, dressing, bathing, fatigue management, home routines and equipment. See the wider rehabilitation guide for goal-based planning.

Oral medication

Oral baclofen is commonly considered first when MS-related spasticity causes a defined problem such as pain or impaired mobility. Gabapentin may be considered when baclofen is not tolerated or does not provide enough relief. Other medicines, including tizanidine or selected night-time treatments, may be used depending on the country, symptoms, medical history and specialist advice.

These medicines can cause sleepiness, dizziness, weakness and other adverse effects. The safest option and dose depend on kidney function, other medicines, falls, breathing risk and the role that tone plays in function. Baclofen and some other drugs must not be stopped suddenly. Dose changes and withdrawal plans belong with the prescribing clinician. Read our overview of oral medications for spasticity.

Cannabinoid-based medicine

Nabiximols, an oromucosal cannabinoid medicine, is available for selected adults with moderate to severe MS spasticity in some healthcare systems when other treatment has not provided adequate relief. It is not the same as using unregulated cannabis. Eligibility, a supervised trial, driving advice, cognitive and psychiatric risks, interactions and local prescribing rules must be reviewed by an appropriate clinician.

Botulinum toxin for a focal pattern

When a limited group of muscles creates a clear problem, such as painful hip adduction, a clenched hand or an ankle pattern that interferes with foot placement, botulinum toxin may be considered. The injection weakens selected overactive muscles temporarily. Muscle selection, dose and follow-up should be linked to a functional or care goal and combined with an appropriate rehabilitation plan. See botulinum toxin injections for spasticity.

Intrathecal baclofen

For severe, widespread spasticity that remains problematic despite other approaches, a specialist team may assess whether intrathecal baclofen is appropriate. Medication is delivered into the fluid around the spinal cord by an implanted pump. Screening, surgery, refills and urgent planning for possible pump or catheter problems are essential. It is not a routine option for mild symptoms. Read the detailed guide to intrathecal baclofen pumps.

Orthoses and other interventions

An ankle-foot orthosis, hand splint, seating adjustment or other support may improve stability, positioning, comfort or hygiene when it fits a defined need. Skin and pressure must be monitored, especially when sensation is reduced. Serial casting or surgery is considered only in selected circumstances, particularly when fixed shortening or structural change is part of the problem. Equipment should be reviewed as symptoms and mobility change.

Managing spasticity day to day

Track patterns. Note when stiffness or spasms occur, what you were doing, medication timing, sleep, pain and possible bladder or bowel triggers.
Move regularly. Break up long periods in one position and use the movement plan taught by your rehabilitation professional.
Pace activity. Alternate demanding tasks with recovery and plan around predictable fatigue.
Manage temperature. Use cooling, ventilation, lighter clothing or a cooler exercise setting if heat worsens MS symptoms.
Protect skin. Check areas under splints, footwear and seating supports and respond early to persistent redness.
Review equipment. A brace, walking aid or wheelchair setup that once fitted well may need adjustment.
Do not chase every fluctuation with medication. A temporary increase may have a correctable cause.

A sustainable routine should fit real life. It may include a few minutes of movement during dressing, a planned exercise session, comfortable positioning before sleep and a simple trigger checklist. The best programme is not necessarily the longest; it is the one that is safe, meaningful and possible to continue.

When should you contact a clinician?

Arrange a timely review if stiffness or spasms are worsening, causing pain, disturbing sleep, increasing falls, limiting hygiene or changing walking, transfers or hand use. Contact the MS or rehabilitation team if treatment causes troublesome weakness, marked drowsiness, confusion or a meaningful decline in function. Fever, urinary symptoms, constipation, skin injury or new pain should be addressed as possible triggers.

Seek urgent medical help for sudden one-sided weakness, new facial droop, speech difficulty, severe breathing problems, loss of consciousness, a suspected fracture, rapidly progressing neurological symptoms, or an inability to pass urine with significant discomfort. A new neurological change that persists may require assessment for relapse or another medical cause.

Frequently asked questions

Does every person with MS develop spasticity?

No. Spasticity is common, but MS affects people differently. Some never develop meaningful muscle overactivity, while others experience symptoms that vary by limb, time of day and stage of disease.

Can exercise make MS spasticity worse?

Appropriately selected exercise is generally part of MS management and does not automatically worsen spasticity. Excessive fatigue, pain, overheating or poor technique can temporarily increase symptoms. Reduce the load, cool down and review the plan if the response repeatedly lasts longer than expected.

Is a muscle relaxant always needed?

No. Medication is considered when spasticity creates a problem that matters to the person. Trigger management, rehabilitation, positioning or a focal intervention may be more appropriate in some situations. Any medicine should have a clear goal and a planned review.

Can spasticity be useful?

Sometimes. Extensor tone may help a person keep the legs straight for standing or transfers. Reducing it can reveal weakness. This is why assessment should include real tasks and why treatment decisions should be shared with the person.

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Medical disclaimer: This information is provided as a public service for general education. It is not a substitute for personal medical advice, diagnosis or treatment. Speak with your MS or rehabilitation team before changing medication, exercise or another part of your treatment plan.

Last updated: September 15, 2026. This page has not been medically reviewed.