Exercise and Spinal Muscular Atrophy (SMA)

 Spinal Muscular Atrophy (SMA) is a rare genetic condition affecting nerves in the spinal cord that are important for movement control, known as motor neurons. Damage to the motor neurons means signals to the muscles can’t get through properly, causing them to gradually weaken and waste away (atrophy). People affected by SMA experience difficulties with muscles throughout their bodies, including:

• those in the back, hips and shoulders – which can lead to difficulties with posture and mobility
• muscles involved in swallowing – which can lead to feeding difficulties
• muscles involved in breathing and coughing – which can make the affected person more prone to chest infections.

People with SMA may also experience muscle twitching (called fasciculations).

There are many types of SMA, and symptoms vary from one person to the next. SMA does not affect an individuals’ intellectual function. To help ensure people with SMA can maintain good health and to minimise disability related to their condition, they need ongoing support from healthcare professionals such as Accredited Exercise Physiologists (AEPs).

WHY IS EXERCISE IMPORTANT FOR PEOPLE WITH SMA?

Because SMA involves progressive muscle weakening, maintaining muscle strength for as long as possible is a key aspect of management. Exercise is the mainstay of keeping muscles healthy. For children and adults with SMA, exercise can help to slow decline in muscle function, improve physical and mental wellbeing, and enhance quality of life.

While there is limited research into exercise for people with SMA, recent studies generally suggest it is safe and beneficial. For example, one study in which five people with SMA type II completed 12 weeks of supervised arm cycling found the participants significantly improved their active cycling distance and duration.

Another study of nine children with SMA found that a 12-week supervised, home-based, resistance exercise training program was safe and well tolerated. More research will throw light onto how people with SMA respond to exercise and aid the development of exercise guidelines for this condition.

WHAT TYPE OF EXERICES IS BEST?

SMA affects everyone differently. For example, some people will experience more difficulties with breathing, while others will have challenges with posture, muscle tone, or mobility. A professional with expertise in prescribing exercise for people with specific health conditions – like an AEP – can tailor a program to suit your individual needs. An exercise program for people with SMA will typically include a variety of exercises and training of support people where needed.

Resistance training

Muscle weakness is the main characteristic of SMA, and can lead to problems with co-ordination, motor skill development, posture and mobility. Resistance exercises help to build or maintain muscle strength and endurance and thereby improve function. It’s important to note that exercise cannot reverse the damage caused by SMA, but it can help to optimise and maintain muscle function.

Aerobic exercise

Regular aerobic activities, such as walking, cycling (including arm cycling and recumbent cycling), swimming, dancing, boxing or rowing, helps to keep the heart, lungs and circulation functioning at their best. It can assist with healthy weight maintenance, and also activates release of the ‘feel good’ hormones that support a positive mood.

Stretching

People with SMA can be at risk of developing muscle shortening and joint stiffness. Stretching exercises can help to maintain flexibility and reduce the risk of contractures.

Breathing exercises

These can help to improve or maintain the strength of muscles involved in breathing and coughing.

TRAINING SUPPORT PEOPLE

Some people with SMA, especially infants and children, will need support to exercise. Children, for example, will need help from parents and/or carers to complete exercises that help with the development of motor skills. Adults with physical disability may need support to access community exercise facilities or to exercise safely at home. Increasing the capacity of caregivers helps ensure individuals with SMA can achieve their health goals with reduced reliance on support from healthcare professionals.

GUIDANCE FROM AN ACCREDITED EXERCISE PHYSIOLOGIST

People living with SMA have complex and varied needs, so it’s important to get guidance from an Accredited Exercise Physiologist before starting an exercise program.

For example, people with SMA can fatigue more quickly during exercise than those without the condition, so they may need a modified program. Muscle weakness may increase the risk of falls or injuries, so caution is needed with activities that require a high level of balance or co-ordination.

Some people with SMA need modified equipment, such as adaptive bicycles that allow you to pedal with your hands instead of your legs.

An Accredited Exercise Physiologist will consider all these factors in their assessment and planning. Your AEP will create a customised program that considers your (or your child’s) function, goals and activity preferences. Safety is a key consideration, and your program will be updated to adapt to any changing needs. Your AEP can also train carers and support people to help exercise become an enjoyable part of your (or your child’s) everyday routine.