SMA can weaken the muscles that support the spine. Without this support, it can be pulled by gravity and curve.  It is estimated that of the people who have SMA and are unable to sit or can sit but not stand and walk, between 6 and 9 out of every ten (60-90%) develop a spinal curvature.  For people who can walk it is 5 out of every 10 (50%).

• When the spine curves sideways into a “C” or “S” shape it is called a scoliosis.
• When the spine bends forward it is called a kyphosis.

At the same time as the spine curves, there are changes to the chest wall and rib cage. This reduces the space available for the lungs to grow and for breathing.

Weakening muscles can also mean that some people who are sitters and walkers have ‘unstable hips’. How much muscles weaken and what effect this has on anyone’s spine and hips day-to-day is very individual – no two people are the same.

Another issue for many who have SMA is being unable to use bones and muscles as much as someone who can walk. This makes you more at risk of bones being weaker and more likely to break (osteoporosis) causing bone fractures.  If you can, standing can help with this as well as being good for many things including:

• breathing
• blood circulation
• bladder
• bowels
• joints.

Your physio and OT can tell you more about how and why.