What can cause weak glutes and hamstrings and no feeling in the leg at all?

Nerve compression: Nerves that normally provide sensory and motor function to the leg can be compressed as the exit the spinal cord with impeding bone, scar, and/or intervertebral disc tissue that is bulging or otherwise pressing on the nerve. Once the compression is bad enough, weakness and numbness can occur. Seek evaluation of your lower back with a back specialist.