What is Sciatica?
April 23, 2019
Sciatica is a misused waste basket term. It’s used classically for “leg pain”. Unfortunately, Sciatica is not very descriptive of the real problem. The sciatic nerve is a nerve that comes from the L4-L5-S1 and maybe S2 nerve roots and comes together through the buttocks muscles down the back of the thigh and distributes out to the various parts of the muscles and skin to provide sensation and motor function.
Pressure on that sciatic nerve can be construed to be the problem but it generally comes from pressure against the specific nerve root that I mentioned earlier. A herniated disc pushing up against the nerve or facet subsiding with degenerative changes. Pressure along that particular nerve root will cause pain down the leg.
One of the questions I always ask my patients does the pain go down the:
- back of the thigh?
- side of the thigh?
- front of the thigh?
The front of the thigh is the L4 nerve root. The back of the thigh is the L5 or S1 nerve root. I also ask if the pain goes above the knee or below the knee? If the pain doesn’t go below the knee, generally it is a muscle problem. If the pain does go below the knee, it goes to the lateral calf or the top or bottom of the foot which is the L5 or S1 nerve root. This is known as Pain – Radiation – Referral.
The problem is a Sciatica can be from a degenerative hip . Sciatica can also come from a Gluteus-Medius or buttocks muscle spasm that is tight because someone has a stiff lumbar spine. I often also see very tight biceps-femoris muscle which goes to the lateral aspect of the tibia which goes below the knee and attaches to the ischial tuberosity (the little bone we sit on). If that muscle is in spasm, it can be severe and uncomfortable. The tightness of this muscle causes ischemia or less blood supply to the muscle causing alot of burning. If one sits in the car and has to get out and walk with this type of pain, it becomes apparent that walking can stretch the muscle and restore the blood supply.
To summarize this, Sciatic pain can come from many different causes, not just from a pinched nerve. Just because you have Sciatic pain, it’s not a trigger to get an MRI. A clear diagnosis with a straight leg raise as being positive (less then 30 degrees) and some neurological deficit; numbness, tingling, quadriceps weakness, inability to walk on the toes or the heels, etc.
All of these are indicative of a neurological compromise for true Sciatica. The term Sciatica should not be used across the board, because the specificity of the diagnosis is really important to solve the problem.
