What is Sciatica?
By: Dale J. Buchberger, PT, DC, CSCS, DACBSP
It is a common misconception that “sciatica” is a condition when in reality sciatica is a symptom. It is a symptom that may have a multitude of causes or predisposing factors. The most common symptom pattern is leg pain, which might feel like a bad leg cramp, or it can be excruciating, shooting pain that makes standing, sitting or sleeping nearly impossible. The sciatic nerve is the longest and widest nerve in the human body. It begins as a series of individual nerve roots in the lower back, joins together in the buttocks extending down the legs, ending just below the knee where it splits into two different nerves that control the leg, ankle and foot.
Sciatic pain is typically made worse when you sit, sneeze, cough or move your bowels. Sciatica can occur suddenly or it can develop gradually. You might also feel weakness, numbness, or a burning or tingling (“pins and needles”) sensation down your leg, possibly even in your toes. Less common symptoms might include the inability to bend your knee or move your foot and toes. What causes sciatica? Sciatica might be a symptom of a “pinched nerve” affecting one or more of the lower spinal nerves. The nerve might be pinched inside or outside of the spinal canal as it passes into the leg. Conditions that cause sciatica: A herniated disc can cause direct pressure on a nerve root. This is the most common cause of sciatica. Spinal stenosis is a condition that results from narrowing of the spinal canal putting pressure on the exiting spinal nerves. This is usually degenerative in nature caused by excessive arthritic development in the canal. Walking with a flexed or bent over posture is a common symptom of spinal stenosis. Spondylolisthesis or a slippage of one vertebra on a another so that it is out of line with the one above it may cause narrowing the neural foramina or opening through which the spinal nerve root exits.
Several conditions or disorders of the hip can cause sciatic like symptoms. Piriformis syndrome develops when the piriformis muscle, a small muscle that lies deep in the buttocks, becomes tight or spasms. The sciatic nerve runs directly under the piriformis muscle. Once this muscle becomes shortened or tight it can put pressure directly on the sciatic nerve resulting in irritation and the typical symptoms of sciatica. Two other conditions of the hip can cause the muscles in the hip to also tighten around the sciatic nerve resulting in pain down the leg. Avascular necrosis of the hip, which is essentially, death of the hipbone caused by poor circulation. The other is femoral acetabular impingement or FAI of the Hip. Since the hip is a ball and socket joint either the ball portion can become mis-shaped or boney spurs can grow off of the socket causing the tendons of the hip to get pinched or impinged. This ultimately limits the range of motion. This limited motion causes the surrounding muscles to become tight and again compressing the sciatic nerve.
Another yet more remote cause of sciatica that we have seen clinically is known as a sports hernia or athletic pubalgia. Simply put a sports hernia occurs when the tendons of the lower abdominal muscles begin to degenerate and thin out and eventually tearing. Once the abdominal tendons begin to tear the pubic symphysis (the area at the bottom of the abdomen where the pelvic bones join) can become slightly unstable. This causes the small rotator muscles of the hip including the piriformis muscle to spasm and compress the sciatic nerve.
As you can see “sciatica” is not as straightforward as many people would have you believe. If you perform simple stretching exercises, over the counter anti-inflammatory such as ibuprofen (Advil or Motrin) or naproxen sodium (Aleve) and ice to the lower back region that fails to resolve the sciatic pain in 14 days you should see a healthcare professional and be assessed for one of the previous underlying causes of sciatic pain. This may involve an XR to assess the bone structure or an MRI to assess the soft tissue components such as the muscles, tendons, ligaments or spinal discs. Once this information is available your doctor, chiropractor or physical therapist can formulate a plan to treat the underlying cause of the sciatic symptoms.
More times than not the cause and symptoms of sciatica can be treated conservatively with a combination of physical therapy based treatments. Manual therapy techniques such as joint mobilization or manipulation are commonly combined with soft tissue treatments such as Active Release Techniques. Therapeutic exercises designed to strengthen the hip and CORE muscles are combined with stretching exercises. An experienced healthcare provider can formulate a home exercise program in order to assist recover and prevent recurrence of your sciatic symptoms.