How Likely Are You To Have Sciatic Pain? (Piriformis Syndrome)
Piriformis syndrome is a neuromuscular issue that can be felt as pain at the buttocks and hip. The piriformis muscle is a deep rotator (internal and external) of the leg. The piriformis also plays an important role in the stabilisation of the sacroiliac joint (SIJ).
Piriformis syndrome can be an under-diagnosed condition as the symptoms can be similar to that of lumbar radiculopathy, primary sacral dysfunction, or innominate dysfunction.
What is piriformis syndrome?
The piriformis muscle originates from the anterior surface of the sacrum and attaches to the greater trochanter of the femur. If the piriformis is hypertrophied it can compress the sciatic nerve (which is typically underneath the piriformis), causing piriformis syndrome. This is similar to the compression of the median nerve by the pronator teres, known as pronator teres syndrome.
I’ve had many clients over the years who have suffered from piriformis syndrome. A study had found that more than 16% of all adult work disability work evaluations performed were linked to lower back pain. (Centers for Disease Control and Prevention. Prevalence of disabilities and associated health conditions among adults—United States, 1999 [published correction appears in MMWR Morb Mortal Wkly Rep. 2001;50:149]. MMWR Morb Mortal Wkly Rep. 2001;50:120-125.)
Diagnosis had shown that over 6% of those who suffered with lower back pain actually had piriformis syndrome. (Hallin RP. Sciatic pain and the piriformis muscle. Postgrad Med. 1983;74:69-72.)
So it is clear that piriformis syndrome can be a debilitating experience for people. Like many issues in the body, a person’s lifestyle (sports, movement patterns, postures, emotions) can be the cause to these issues. But are some people more likely to suffer with piriformis syndrome due of their genetics?
Sciatic nerve and piriformis genetic variations
The genetic variations of the sciatic nerve and piriformis are:
- Sciatic nerve passing under the piriformis (top).
- Sciatic nerve passing through the piriformis and the tibial nerve passing under (bottom left).
- Sciatic nerve passing under the piriformis and the tibial nerve passing over the piriformis (middle)
- Sciatic nerve passing straight throw the piriformis.
Based on the research done on cadavers the sciatic nerve passing underneath the piriformis is the common variation, about 90%. The variations where the sciatic nerve passes through the piriformis may leave someone more likely to experience sciatica in their life. It is clear with these genetic variations that sciatic treatment is not the same for everyone.
Sciatica can also be caused by other factors other than the piriformis so this is not a straightforward situation to treat.
Improving piriformis function
As mentioned earlier the piriformis is an external rotator for leg. When you go into 45-60 degree of hip flexion, the piriformis will become an internal rotator. It reverses it’s action on the leg. This means that in the cross legged position we can resist internal rotation of the thigh and perform a muscle energy technique (MET) on the piriformis and the other muscles that internally rotate the leg. This can help with improving the piriformis’s capacity to contract which in some of you can alleviate compression at the sciatic nerve (assuming the piriformis is overly compressing your sciatic nerve in the first place). I’m not saying this is a cure for sciatica but it can definitely alleviate neural tension in some people as I have witnessed this when performing this exercise on clients.
Here is the exercise…
- Press your knee into your hands (internal rotation)
- Pressure from the knee is only 20% of you maximum. No movement – isometric contraction.
- Hold for 20 seconds.
- Repeat 4 times. Then swap legs.