What are some of the symptoms of spondylolysis and spondylolisthesis?

Many: Both conditions give different set of symptoms if nervous tissue are involved. Pain in spine area, crackling sound on movement, painful movement with or without restriction. Weakness, numbness, tingling, spasm, bladder control. Etc.

Several possibilitie: From least severe to most severe: back pain, pain/numbness/tingling in legs, weakness in defined muscles of legs/calves/feet. Change of brel and bladder control.