Spasticity and muscle spasms

Your muscles play a role in every movement you make – helping you walk, balance or even stay still. In multiple sclerosis (MS), these muscle movements can be affected by spasticity – when muscles become stiff, tight or twitch involuntarily.

MS spasticity and muscle twitching are common symptoms that can vary from mild stiffness to painful muscle jerks or spasms. With the right treatment, exercises and support, these symptoms can be managed to improve comfort and mobility.

What is spasticity?

Spasticity is one of the most common MS symptoms. In MS, the brain's messages telling muscles to righten or relax can become delayed or blocked, causing the muscle to stay contracted or suddenly twitch. It causes stiffness or muscle spasms due to disrupted nerve signals between the brain and muscles. For some people, this muscle stiffness or twitching can cause pain, fatigue, or difficulty walking, sleeping or completing daily tasks.

Spasticity can affect any muscle, but it most often involves the calves and thighs, inner thighs (adductors), arms, wrists and fingers.

Spasticity vs. muscle spasms and twitches

While they’re related, spasticity and spasms are not the same:

• Spasticity – Ongoing muscle stiffness or tightness (also called spastic paresis).
• Spasms – Sudden involuntary contractions that may come and go.
• Muscle twitching (fasciculations) – Small, repetitive muscle jerks, often in the shoulder, forearm or around the eye or forehead.

Some people with MS describe twitching in one forefinger, a twitching shoulder muscle, or eye twitching with MS. These small movements may be harmless but can also signal MS-related nerve irritation.

How spasticity affects the body

Common signs of MS spasticity include:

• Muscle tightness or pain
• Difficulty relaxing or straightening a limb
• Uncontrollable muscle jerks or shaking
• Involuntary twitching in the legs, arms or face
• Fatigue or stiffness in joints and the lower back

Because spasticity makes your muscles work harder, it can increase tiredness and cause soreness over time.

Types of MS-related spasticity and spasms

Triggers and causes

Certain triggers may set off spasticity symptoms. While different for everyone, they may include:

• Infections or other health conditions
• Tight clothing
• Heat, cold, anxiety, fatigue, stress or overexertion
• Sudden movements
• Certain medications
• Other MS symptoms, such as bowel or bladder problems and pain.

Identifying and avoiding triggers can help reduce muscle twitches and spasms.

Managing spasticity, spasms and twitching in MS

If you notice new or worsening muscle twitching, shaking or spasticity symptoms, speak to your MS Nurse, GP or neurologist. Treatment options include:

Movement and stretching

Regular movement, stretching or gentle exercise such as yoga or Pilates can keep muscles flexible and reduce spasms and twitches. A physiotherapist or exercise physiologist can guide you through safe stretching routines and postures to prevent tightening.

Therapy and medication

Your healthcare team may suggest:

• Physiotherapy or exercise physiology
• Muscle relaxants or antispasticity medications
• Stress management or relaxation techniques

Peer and emotional support

Living with twitching muscles or spasticity can be frustrating. Our Peer Support program connects you with others living with MS who understand these challenges and can share practical coping strategies.

When to seek help

Contact your healthcare team if spasticity or muscle twitching causes:

• Pain or limited movement

• Difficulty walking, sitting or sleeping

• Emotional distress or loss of independence

Early management helps prevent worsening stiffness and supports better comfort and mobility.