Sciatica. The sciatic nerve goes from the lower back, through the buttock on both left and right, and down the back of the leg to the foot. Pain starting in the low back going down the back of the leg, or pain in the buttocks that goes down or up to the back are likely to be sciatica. There are some serious reasons for sciatica, such as disk damage, so it is suggested that you check with your physician.
It is pain that . Pain that radiates down the leg from the buttocks or back down the leg below the knee that is generally made worse with prolonged positioning or activity & better with rest. Sometimes it may be associated with numbness, tingling or weakness. The pain can vary in intensity & sometimes feel like an " electric shock." the pain can be a continuous one over the path of the leg or can skip areas.