I need to know what's an injury that makes a person not be able to walk but can be recovered from?

Lumbar spine strain: A low back strain or even a herniated disk can affect ambulation. You can completely recover from a lumbar strain; however, a herniated disc can be severe enough that you may need invasive medical treatment to restore normal motor function.

S;inal cord injury: You can experience inability to walk but recover from an bruising of the spinal cord. The process is sometimes called spinal shock.