Hello Martin
With the amount of damage to your back,I would expect you to have been in sever pain and needing medication for it!!!
The consultants must have done a Skelton ex ray plus MRI,scan which show the damage,if it’s pain from that area ,there should be some relief as chemo does the job of removing cells,but if it’s the bones crumbling as the treatment works causing nerve pain,that is different.
Most people take a bone strengthener like Zometa which helps.
You alone know your body,listen to it,ask your consultant or see your doctor,excise in small doses is good for you,helps strengthen muscle around the bones.
You have to learn to be vocal with this disease,but first you have to find out what is causing the pain,lots of people are on very strong pain relief,you have a lot of damage to your spine,which could relate to Myeloma itself or damage caused by Myeloma causing more problems,you need to know which. Eve