The Sciatic nerve runs from your lower back, through the buttock area, down the back of your leg and to your foot. It is a very large nerve and is commonly affected by low back injuries. Often the pain in your leg is worse than your back. Other sensations are common such as pins and needles or numbness and weakness of the leg. The reason it becomes a problem is because it takes a nerve branch from many different levels of your spine, most of these levels are the ones commonly overstrained or injured.