Bilateral leg pins and needles with back extension

Hi
I have recently had a patient come in complaining of bilateral leg P&N in the posterior thigh and mild lower back and buttock pain on upright standing and back extension, flexion eases symptoms off totally. Nil other red flags and neuro is all intact. Has anyone come across this?

dear dawn

sounds like a textbook case of either one of the following...spondylolisthesis, spinal stenosis, large disc herniation...is this person elderly?