Skip to main content

Muscle weakness is common in MS. You may feel like you don’t have the energy or strength to move your body or some of your limbs. Learn more about the types of MS muscle weakness below.

A health professional can work with you to strengthen your muscles and provide tailored solutions for any weakness or other symptoms you may be experiencing.

How does MS lead to muscle weakness

Weakness can be a direct result of MS. This can be caused by damage to the nerve fibres (also known as demyelination) in the brain and spinal cord that send messages to your muscles. Usually, the muscles would receive messages to move through a contraction. MS causes these messages to slow down or be completely disrupted, which can lead to weakness in the muscles.

This is known as primary muscle weakness, as it’s directly related to MS.

Secondary muscle weakness occurs when muscles lose function or strength through being used less, which can happen due to fatigue, pain, poor balance and other MS symptoms.

While it’s not caused by damage to the central nervous system’s nerve pathways, it can lead to other MS symptoms. This can make a person less likely to be active and result in weakened muscles.

For secondary muscle weakness, research shows us that strength training can be an effective way to regain muscle strength.

How can muscle weakness affect people with MS

You may experience MS muscle weakness anywhere in the body, including your:

  • hips
  • knees
  • ankles
  • upper body
  • arms.

Muscle weakness can make it harder for you to move, stay active, maintain good balance, and carry out day-to-day tasks.

Whether your muscle weakness is a primary or secondary result of MS, a physiotherapist can work with you to identify any muscle weakness and give you a training program to start rebuilding your strength.

How muscle strength is measured

Often, health professionals will measure muscle strength using the ‘Manual Muscle Testing Scale’. This is a 6-point scale ranging from 0 (no muscle contraction) to 5 (normal muscle contraction).

Ways to manage or improve muscle weakness

The first step to managing MS muscle weakness is to determine the root cause, which your GP or MS nurse can help establish. You may be referred to allied health specialists – such as a physiotherapist, occupational therapist or physical therapist – who can help you strengthen your muscles and manage day-to-day life.

If it’s primary weakness, the best approach is often to maintain the muscles that aren’t getting enough nerve signals by engaging them and strengthening the surrounding muscles.

For secondary weakness, your therapist will usually create a tailored weight-training program that targets and strengthens your weakened muscles.

Regular exercise

  • Regular exercise can help you maintain or strengthen muscles, improve posture, flexibility, increase endurance and reduce levels of fatigue. Regular exercise is also linked to maintaining strong mental health.

Assistive devices

  • Assistive devices, such as a walker, cane or braces can help you get around more safely and independently. An occupational therapist can give you advice on what assistive devices or technology could help you.

Medication and therapies

  • Your doctor may prescribe medication or therapy to target primary muscle weakness.
  • This may include steroids, muscle relaxants, glatiramer acetate (Copaxone), plasma exchange or interferon-beta therapy.

This page has been reviewed and approved by Executive Manager Client Engagement and Wellbeing Jodi Haartsen. Jodi is a registered MS Nurse who has helped thousands of patients over her 20 years’ experience at Eastern Health MS service in Australia, in several roles including nurse educator, research nurse and nurse practitioner. Jodi is the 2022 winner of the global MS Brain Health Leader Award in the Independent Healthcare Professionals category.

Learn more about MS

Get news and updates from MS Plus

Sign up