What can be done for sciatica pain? why is it worse when i sit and better when when i stand? when i sit i have burning in the back and to the knee?

First, 90% get : Better over time no matter what you do but guided exercise such as physical therapy, medication, activity modification & pain management injections like epidural steroids can help. It is worse sitting as that generates 4 times body weight across the discs of the lower back while standing generates only 2 times body weight. Lifestyle changes like not smoking, regular exercise & not smoking help.

Fix the problem: Try some physical therapy, some anti-inflammatories or maybe some steroid injections. Surgery is the last option. When you stand the nerve is shorter than when you sit so there's more tension on the nerve when you're sitting. See your doctor.

Sciatica & position: As per studies by nachemson performed on medical students many years ago, it was found that sitting unsupported generates the most pressure inside the disk. Thus, sitting will tend to extrude the disk and increase pressure upon your nerves and worsen sciatica. Understand, 80% of the time, sciatica from disk herniation heals. Treatment with pt, nsaid's, nerve blocks, surgery if pain persists.

Weeks to Months: Generally most people can get relief from sciatic pain doing the conservative care within 3-6 weeks. If it persists after that, it can take up to 6 months to heal by itself. You may still be a candidate for epidural steroid injections that may help relieve the pain while your body heals itself.