I would suggest that a mobile spine can accommodate the most rigid of mattress. However most are not so mobile and it appears the less mobile the spine in a supine or side lying the more difficult it is to sleep on a firmer mattress.

The problems often include neck, shoulder and arm symptoms on a firm mattress. Yet on the other hand a mobile spine can wake up in all sort of bother on a to soft mattress. My suggestion usually is based on the above assumptions. If you know that the client is not going to change in their spinal mobility, e.g. if they are going to remain kyphotic and rigid, then perhaps a softer option is more comfortable and ? therefore "appropriate".

Many of my clients have purchased over mattress covers made of memory foam from companies such as Harley (www.spinalproducts.com) 8o