I googled it and found this:
When an injury occurs in the back area of the spine, and the individual vertabrae become fractured or dislocated, the back can be described as broken.
These 22 sections form the mid to lower portion of our “backbone” and they also serve to protect the spinal cord from injury. If the vertebrae are broken or severely dislocated, but the spinal cord is unharmed, then no neurological problems result.
People with this type of injury are treated very carefully while the bones heal to avoid damage to the spinal cord.
If the spinal cord is bruised or partially damaged due to swelling or laceration, then paraplegia or other neurological problems may occur.
I think I get it now. His back will either heal itself, or if the spinal cord was also damaged then he might be paralysed in some way. I dont think hes paralysed because he does a lot of walking, which is why I didnt understand why he cant get a job. Most likely he has a neurological problem as that would explain why he cant work...right?