Where can any improvement of sciatica come from?

See a Doc: See a specialist in this area. This usually is a physiatrist who specializes in the treatment of this and similar conditions. Medications, physical therapy, sometimes injections will help.

Spine Pain Options: This pain in the distribution as you suggested is the result of an irritated nerve or facet joints or other injury typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease, etc requiring further evaluation by a spine specialist and may be candidate for facet injections/radiofrequency ablation and epidural steroid injection.