April 25, 2022


Piriformis and its role in sciatica – an article for students

Piriformis syndrome is described by sufferers as “agonising": often experienced after long periods of driving or sitting, the affected leg feels variously as though it’s gone to sleep, or the leg experiences shooting pains, from the hip to the outside of the calf muscle, and the foot can be affected, too. In its full-blown presentation, piriformis syndrome mimics all the effects (symptoms) of nerve compression caused by intervertebral disc extrusion (the ‘slipped disc’ people talk about). A complicating factor is that many people have benign disk pathology (more on this below) but if you experience sciatica (literally “pain in the sciatic nerve”) and you have an MRI or other test and disc pathology is found, the sciatica very likely will be attributed to it. The problem is that there is a potential biomechanical and muscular problem associated with the hip that can cause these effects, but unfortunately, it is rarely tested for, and accordingly is rarely treated. The good news is that you can identify and treat this yourself—read on!


Piriformis is one of four external hip rotators, acting with the adductors to facilitate walking and running, stabilising the femur in the front-to-back or sagittal plane so that the prime movers (gluteus maximus, quadriceps and the hamstring group) can propel the body over the legs. Less known about piriformis is that in about a fifth of the general population, one or both trunks of the sciatic nerve pass directly through this muscle instead of passing between it and the one inferior to it, gemellus. Accordingly, if piriformis is in spasm, or simply tight, it can place sufficient pressure on the sciatic nerve to cause sciatica. (*Later research has identified eight further sub-classes of this grouping, where one or more nerves branch off the trunks inside the pelvis, and these individual nerves pass though piriformis, while the trunks emerge from the pelvis between piriformis and gamellus; see below.)

The Oriental connection

From the Oriental medical perspective, both the lung and large intestine meridian pass through piriformis as they run deeply through the body here and the small intestine and kidney meridians pass above it (following Masunaga, below). We have found that deep elbow pressure (whether applied by shiatsu or deep tissue massage techniques) can be effective in calming this area down, if applied and held still for 15–60 seconds. If you do not have a practitioner, this pressure can be created using a small firm ball, too, by folding the bottom leg across under you, and carefully lowering the affected hip on to it and using your arms to stabilise the body. Static pressure is tolerated better by most people with this problem, but once settled, by all means move around slowly, to find the most effective treatment spots. Let the body ‘melt’ over the ball; this both applies pressure and lengthens the tissues involved.

Click on the image series below to see positioning and instructions.

Necessity of stretching

Pressure alone is rarely completely effective treatment in my experience. After much experimenting, we devised exercise 16 in the book Overcome Neck & Back Pain, which is effective in most cases, and is offered in partner-applied and solo versions. Click on the image below to view the video.

floor piriformis solo and partner

If you don’t have enough hip flexor suppleness to get into the starting position be sure to elevate the hip you are working on using a bolster (this reduces the hip flexor length requirement). If you can’t get in to the starting position, try exercise 5 from the same book. Click on the images below to view the videos.

seated hip
cherie chair piriformis

In time you’ll be able to use the more difficult exercises. Note that sciatica or simple hamstring tightness can make even the easiest of the floor versions difficult to use, in which case the table or chair versions (where the straight leg is bent at the knee) will be effective, because hamstring length will not be a limitation. One or a combination of these exercises, combined with rolling on a ball, has proved effective in both identifying and treating this problem.

In saying this, I mean that  if you have sciatica, and you use either ball rolling or stretching, and the sciatica changes or is reduced, you know you have found one of the causes, at least. Be aware that using these techniques will take time to be completely effective, but most people have found that one repetition of the right stretch provides immediate relief—if this is your experience, you know you’re on the right track. In the figures we kept over the many years we taught at the ANU, and the workshops we have run, about half the people diagnosed with disc-induced sciatica had piriformis syndrome, and the majority responded extremely well to the rolling and stretching protocol.

Maintaining suppleness of the hips, once the problem has settled down

The easiest way to maintain the required range of movement in the hips following successful resolution of the problem is to learn how to do the full squat. By all means use a small lift underneath your heels, and hold on to something in front of you as you try this for the first time. Once you can lower the hips to the back of the lower legs, simply stay in this position while moving your weight subtly from one foot to the other. In time this position will become what it is for most of the rest of the world, a resting position. Occasional use of the advanced piriformis exercise following a 10 minute rest in the full squat position and piriformis syndrome will be a memory for you. Find a tutorial below.

full squat

Further reading:

Travell and Simons, Myofascial pain and dysfunction: the trigger point manual (here, volume 2, p. 186 ff.,1992). Truly excellent anatomical illustrations, too.
Laughlin, K., Overcome Neck & Back Pain., 1995, 1996, 1998, 2006, 2016. The section referred to here will be found in the Causes of neck and back pain chapter, p. 225 ff., in the latest edition.
* For the reference to the other ways nerves can exit the pelvis in addition to the four classes Travell and Simons identified, see Chiba et al., 1994, in the References section of this book.
Shizuto Masunaga. Kit studied with his senior student for a number of years when he lived in Japan.

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