The sciatic nerve is the body's longest nerve. It extends from the spinal cord to the buttocks and hip area, and then runs down the back of the leg. This nerve controls the movements and sensations of your legs and feet. Sciatica may be caused by compression of a nerve root in the lower part of the spine. The compression is often the result of a herniated disk. Disks are the fluid-filled shock absorbers that cushion the vertebrae. Age or injury can cause the fibrous outer sac of the disk to rupture. The jelly-like fluid inside the disk may seep out and put pressure on the nerve. "Sciatic" describes the effects of this compression on the legs and feet.
The pain caused by sciatic nerve damage often follows the pathway of the nerve. This sharp, shooting may begin in the lower back or buttocks, and then travel down the leg, calf and foot.
Numbness and Muscular Weakness
Sciatica may also cause numbness and muscular weakness in the leg, calf or foot. In fact, it's possible to experience a sharp pain in one part of the leg, and total numbness in another part. Numbness can be a serious problem, because it can alter proprioception, which is the body's awareness of its position in space. Altering this awareness may cause falls, ankles sprains and other balance-related injuries.
Pins and Needles
Pins and needles or a tingling sensation in the legs or feet are also aftereffects of sciatic nerve damage.
Chronic pain and/or numbness may cause the patient to alter his alignment and/or gait, as a means of protecting the leg from pain. This may lead to other types of injuries.