Treating patients who complain of sciatica can be daunting as they are often in quite a lot of pain. This higher pain intensity, can be explained, at least in part, by the sciatic nerve possessing a larger amount of ASIC acid-sensing cells than many other nerves. As a result, the pain response from inflammation in or around the sciatic nerve can be greater due to the lower pH inflammation causes in the tissue.
Despite the common presence of a higher level of pain, successful treatment can occur if you follow a few important rules. First, treating the source of the pain usually gives the patient better long-term results than only treating the pain itself. Second, to treat the real source of the pain you have to do a good differential diagnosis to determine where the most likely source is located.
In my clinical experience, the most likely causes of sciatica include the following:
- Pelvic and Hip Dysfunctions: Somatic dysfunctions in the pelvis and hip can cause tightness and irritation in the piriformis muscle on the side of the pain. Piriformis tightness often causes compression of the sciatic nerve that travels under it, and in some unlucky people, through it. Proper treatment should include correcting the mechanical dysfunctions in the pelvis and hip, decreasing muscle tightness in the piriformis, and restoring proper sciatic nerve gliding in the surrounding fascial tissues. Many people, often unsuccessfully, try to treat piriformis tightness through stretching exercises. Keep in mind that the piriformis is a muscle that originates in the anterior sacrum. Like many muscles that derive embryologically from anterior structures, it has a higher degree of neurological input that other muscles as neural crest cells help form it. These types of muscles often respond poorly to stretching. You can get better results by placing the piriformis in slack and adding a little compression into the hip to dampen the neurology allowing the muscle tension to ease. Think of this as rebooting a computer when it starts acting wonky or escaping from the Chinese finger trap toy you may have played with as a child.
- Ankle and Foot Dysfunctions: Sciatic nerve irritation can also begin in the foot and ankle. In some sciatica patients, your evaluation of the pelvis and hip do not reveal much dysfunction. Or at least not enough to cause the degree of pain the patient is experiencing. In these cases, the issue may begin far away from the problem. Be sure to ask, if you have not already, if this patient has a history of foot or ankle injuries. I successfully treated a patient in his 60s with a long history of sciatic nerve pain, who was heading for surgery, by correcting the foot and ankle dysfunctions that occurred from all of his ankle sprains suffered while playing basketball in high school and college. How could this cause sciatica? Ankle sprains often involve dysfunction in the lateral ankle resulting in hypomobility in the joints involving the talocrural, subtalar, cuboid, and fibular structures. Fascial restrictions then result that travel up the kinetic chain that encompass the lateral ankle, peroneal muscles, fibular head, lateral knee, and biceps femoris (lateral hamstring). The biceps femoris attaches to the ischial tuberosity in the pelvis with these restrictions then extending to the sacrotuberous ligament. Resulting sacral restrictions then spread to the sacrospinous ligament that is the floor of the sciatic notch through which the sciatic nerve passes. Treatment of the joint dysfunctions and long-chain myofascial restrictions that extend from the lower extremity to the sciatic notch can take the strain out of the sciatic nerve. Release of piriformis tightness and sciatic nerve gliding techniques work well here also and can complete the treatment. Removing all of these dysfunctions will dramatically increase blood flow to the nerve allowing it to decrease the inflammation and eventually heal.
- Both 1 and 2 are present and you need to treat both areas.
- The sciatica may be discal in nature. The sciatic nerve is derived from the ventral rami of spinal nerves L4 through S3 and contains fibers from the lumbosacral plexus. Disc problems involving the L4-5 and L5-S1 segments can be the source of the problem. While this potential source is the most likely reason given for the sciatica, I find this to be the true cause rarely (see previous posts). Usually when I encounter the issue of a potential discal source of pain, the rationale is based on radiological findings for a MRI, CT scan, etc. But is there clinical correlation? Usually the answer is no and your evaluation will find a much more likely source from the possibilities above. There are a few ways to quickly determine if the sciatica is truly from discal irritation. One is have your patient try to walk on their heels and then toes. A true discal problem will cause sensory, motor, and reflex changes. If the patient can walk on their heels and toes, then no motor weakness is present in the L4-S1 segments. Other quick scans that can be done involve testing neural gliding during straight leg raise and Slump testing. Personally I think about a true discal cause if these tests produce pain and restriction in less than 20 degrees of a straight leg raise and almost immediately with knee extension during Slump testing on the side of the pain. These occurrences are uncommon. I also consider a true disc if the patient’s pain never changes during the day no matter what position they are in.
While treating sciatica can be tricky, finding the true cause is not as hard as you might think, which will lead you to more successful treatments.