Sciatic pain is pain that is experienced because of compression ,irritation, or inflammation in or around the sciatic nerve. The sciatic nerve is a nerve that is combined from the spinal nerves L4 through L3. The individual spinal nerves that combine to form the spinal nerve originate in the lower back, and sacral foramina, and run the entire length of the leg. If the nerve becomes squeezed or irritated along any part of its length, sciatic pain may be experienced. Because the sciatic nerve is the longest nerve in your body, there are many locations along its entire path that may be compressed or irritated. That being said, the sciatic nerve is most likely to become compromised near the location where the nerves leave the spine and around the piriformis muscle.
Piriformis syndrome: the piriformis muscle originates in the anterior part of the sacrum and from the greater sciatic notch of the pelvis. The piriformis muscle then runs laterally and slightly inferior to insert into the greater trochanter of the femur. The piriformis is one of several muscles that are involved in laterally rotating the hip. The piriformis muscle lies just above the sciatic nerve as it passes through the hip and buttocks, and inflammation of this muscle may cause sciatic pain. Let's take a look at some other causes of sciatica, sciatic pain, and related lower back pain.
Lumbar herniated disc: Though the spinal cord actually ends at about the first lumbar vertebra (L1), the spinal nerves continue past this point and exit through the intervertebral foramina of the lumbar spine. The spinal nerves also continue below the last lumbar vertebrae and exit through the foramina of the sacrum. The lower spinal nerves and the spinal nerves that pass through the foramina combine to form the sciatic nerve. Disc herniations in the lumbar discs near the spinal nerves that give rise to the sciatic nerve may cause lower back pain as well as sciatic pain. The discs, when healthy, have a full nucleus of gelatin-like liquid that is housed within a strong outer wall. The gelatin interior is known as the nucleus pulposus, and the outer envelop of the disc is known as the annulus fibrosis. If the fibrosis becomes torn, the pressure on it may cause its gel-like nucleus to shoot out, like squeezing on an open bottle of toothpaste. If this material impacts the sciatic nerve, it may cause dysfunction of the nerve.
Lumbosacral Muscle Strain: Sciatic pain may occur when the Lumbosacral muscles of the back become strained due to poor posture, repetitive stress, and muscular deconditioning. Lumbosacral problems may occur due do to a sedentary lifestyle, poor posture, weight gain, and a lack of exercise. These muscles may also become injured from falls, traumas, twisting without stretching, and poor lifting techniques.
Symptoms of lumbosacral strain include stiffness, persistent pain, and a dull ache in the lower back and the sacral region. These symptoms are likely to become more intense after physical activity that challenges the lower back. As a result of the injury, these muscles become chronically tight, or tense while physical activity is occurring, and the tenseness of the muscles causes them to press against the sciatic nerve.
Sciatic pain may also be causes by spinal stenosis, ruptured discs, emotional stress, arthritis, endometrial cysts, ankylosing spondylitis, and sacroiliac ligament tears.