It could be possible that a pinched nerve cause sharp pains in lower back?

Numb leg: Yes! sharp pain in a lower extremity due to nerve compression can cause this. Relieve by squatting down to flex the lumbar spine. Usually, anti-inflammatory medications can help, as well as some core strengthening with a flexion-based exercise program. Make sure nothing else is the cause of the leg pain! see a doctor and maybe have a scan performed. U need a diagnosis!

Nerve impingement: Pinched nerve can cause back pain. The other possible causes are muscle strain, spinal stenosis, ruptured disc...