Are you a dedicated cyclist who recently has begun to experience pain in the hip and leg area? Are you a runner, who suddenly is experiencing pain on sitting, or climbing stairs? Are you a dedicated equestrian, practiced in the art of Dressage? If any of these scenarios sounds familiar, it is possible you are suffering from piriformis syndrome. The condition can be very painful, and chronic, but it usually does respond to treatment. Apparently, the sooner treatment is begun, the better your outlook for a less painful future.
Dancing: May Lead to Trouble with the Piriformis
GIF constructed from multiple Pixabay images by 3D_Maenchen
After years of dancing, and not necessarily breakdancing (ballerinas get it too) your piriformis may sharply inform you of its presence and you may feel something like this:
Prolonged Sitting Can Lead to Piriformis Syndrome
As a matter of fact, pain when sitting, or after sitting, is one of the symptoms that helps in making a differential diagnosis.
In order to understand how the piriformis can act up in so many different situations, it's a good idea to understand the neighborhood in which the piriformis resides. One of its closest neighbors is the sciatic nerve. This nerve, the longest in the human body, is a source of agony for millions. As it wends its way it stops to inflict pain randomly. One of its painful stops may be the piriformis muscle.
Composite Picture of the Sciatic Nerve From the Lumbar Spine to the Hip, and From the Hip Down Through the Leg
How Many Times Have You Heard People Complain of Sciatic Pain?
Look at the diagram (above). Note the number of nerve roots coming from the lumbar region of the spine, and from the sacrum. This design is a built in vulnerability. Vertebrae over time are subject to injury, and stenosis. Vertebrae thus affected often compress one of the nerve roots. When this happens, the pain is excruciating. It is also, potentially, disabling.
According to a 2007 article in the Boston Medical Journal, between 49% to 70% of all people will suffer from low back pain over their lifetimes. Of that number it is estimated that between 5% and 10% will have sciatica (that is, low back pain due to sciatica). Overall, the Journal estimates that about 2.2% of the population will experience disc-related sciatic pain every year.
Sciatica Caused by Inflammation of the Piriformis Muscle
Although most people, and even physicians, think of sciatica as originating in the lower back, a small percentage of cases originate with inflammation of the piriformis muscle, in the hip. The piriformis is one of six muscles that help to rotate the hip externally. All six attach at the greater trochanter (see diagram above), at the top of the femur. Together these six muscles are known as the lateral rotator group.
If you're interested in learning about the exact location of these muscles, this YouTube video goes into greater detail.
Dressage: Not Good for the Piriformis
Adapted from a Pixabay vector image
The sport of dressage, which places strain on the horse because of repetitive movements, also poses injury risk to the rider. Among the rider's risks is piriformis syndrome. Ironically, the horse does not run this risk. It seems the piriformis is becoming vestigial in horses.
Relationship Between the Piriformis and Sciatic Nerve in Humans
This diagram shows an inflamed piriformis impinging on the sciatic nerve. I constructed the image with a public domain illustration of the hip as a base. Using information derived from Science Direct, Piriformis Syndrome, I added the muscle, nerve and femur.
While the diagram above shows the sciatic nerve running beneath the piriformis, this is not true in all cases. In some people the sciatic nerve actually weaves through the piriformis. It is not known how often this occurs, though some estimate the number to be around 10%. It is not certain that this anatomical variation affects the risk of developing piriformis syndrome. A 2016 article in Translational Research in Anatomy suggests that the variation may be significant, and that identifying it may be helpful in deciding on a course of treatment.
Sciatic Nerve Entrapment
The difficulty with the relationship between the piriformis and the sciatic nerve arises with nerve entrapment. If the piriformis becomes inflamed, or spasms, it will impinge on the nerve. Besides being painful, this entrapment can lead to serious, long-term consequences.
Diagnosing Piriformis Syndrome
This is obviously not an MRI image of the piriformis. I couldn't get a public image version of that. However, this does show the lumbar region where many cases of sciatica originate. Distinguishing between sciatica that originates here and piriformis syndrome is often a challenge.
Diagnosing piriformis syndrome takes skill. As a matter of fact, there are some who suggest that piriformis syndrome is overdiagnosed, and that the issue is often merely a matter of an inflamed piriformis muscle. In order for the diagnosis to be a true piriformis syndrome, the sciatic nerve must be involved.
Physical examination of the patient is helpful, as are MRI images. A 2019 article published by the American Academy of Physical Medicine and Rehabilitation explains that diagnosis of this syndrome is difficult precisely because so many areas may be affected by inflammation of the piriformis muscle. The symptoms of the syndrome overlap with those of sciatica caused by disc compression, sacroiliac joint disease and even carcinomas that may affect nearby tissue.
Piriformis Syndrome in Dogs
Dog GIF created from Pixabay image by Cocoparisienne/.2626imagenes
Most people who have dogs as pets, particularly certain breeds, are familiar with a condition known as hip dysplasia. This can be painful, and even disabling. It seems that some cases diagnosed as hip dysplasia may actually be cases of piriformis syndrome. The location and function of the piriformis muscle in canines is remarkably similar to that in humans. In a fascinating article by Maja Guldborg, DVM, the case study of a Labrador named Iris is discussed. Iris was treated successfully for piriformis syndrome. Dr. Guldborg applied the same physical therapy remedies for Iris' condition that would be used to treat a human with piriformis syndrome.
Function of the Piriformis Muscle
The pirifomis muscle is essential to the proper rotation of the hip. It helps to stabilize the femur in the hip socket (the aetabulum).
GIF constructed from a Pixabay image.
The figure in the picture demonstrates the external lateral motion that is controlled by the six external rotator muscles that attach to the femur. The piriformis is essential in this action.
Incidence of Piriformis Syndrome in the General Population
While the U. S. National Institute of Neurological Disorders and Stroke characterizes the syndrome as a "rare neuromuscular disorder",
other sources suggest it may not be so rare. A 2013 study in India attempted to assess just how common the syndrome was.
The subjects of the study, 2910 of them, all had lower back or buttock pain associated with sciatica. Age range of the patients was between 15 and 81. The study lasted two years. Results? 6.25% of the patients were found to have piriformis syndrome.
There are several approaches toward treatment. According to an article published by Cedars-Sinai most of the treatments involve conservatively stretching and working the piriformis muscle. The most common approach is physical therapy. Application of heat is frequently recommended. Over the counter anti-inflammatory drugs are also sometimes prescribed.
There are more invasive approaches. These include injection with cortisone, and botulinum. In the most extreme cases, surgery has been tried. This last intervention of course carries the greatest risk.
This list is short, since so many different activities can lead to the development of piriformis syndrome. Skilled advice should be sought early if you experience persistent pain in the hip and leg area. That's what the experts say. It seems like a reasonable recommendation to me.
I'll end with a lovely picture of a mouse. We owe mice so much. They endure pain and suffering to advance human health. Apparently one area of research that mice have endured involves the piriformis muscle.
Mice were used in a study that sought to find a remedy for hip dysplasia in young adults. One procedure to which the mice were subjected was detachment of the piriformis muscle.
Thank you for spending your time with me
Some Sources Used in Writing This Blog
(Animals in the logo image are from Pixabay)
Velo News Piriformis Syndrome and Cycling
The Daily News Running Doc: Tips for Dealing with Piriformis Syndrome
Fran Griffith The Periformis
Healthline.com *Differential Diagnosis
Inner Body Sciatic Nerve
Medscape Lumbar Spine Trauma Imaging
Mayo Clinic Spinal Stenosis Symptoms and Causes
Columbia Spine Sciatica
Boston Medical Journal Diagnosis and Treatment of Sciatica
Yoganatomy Deep Six Lateral Rotators
Semantic Scholar Lameness in the Sport Horse
Peacelovehorses.wordpress.com Copmmon Rider Problems
mywowbb.com Dr. Deb Piriformis Muscle
Science Direct Neuroscience: Piriformis Muscle
Midwest Spine Piriformis Syndrome
Translational Research in Anatomy Anatomical variations of the sciatic nerve, in relation to the piriformis muscle
Muscle Ligaments and Tendons Journal Deep gluteal space problems: piriformis syndrome, ischiofemoral impingement and sciatic nerve release
Osteopath-west.co.uk Piriformis Syndrome or Just a Pain in the Butt
Journal of Clinical Imaging Science Diagnosis and Management of Piriformis Syndrome: A Rare Anatomic Variant Analyzed by Magnetic Resonance Imaging
American Academy of Phyiscal Medicine and Rehabilitation Piriformis Syndrome: A Narrative Review of the Anatomy, Diagnosis, and Treatment
Acupuncture for Sports and Trauma Rehabilitation CHAPTER 14 - General Principles of Treating Soft Tissue Dysfunction in Sports Injuries
Journal of the Medical Society Prevalence of piriformis syndrome among the cases of low back/buttock pain with sciatica: A prospective study*
Cedars-Sinai Piriformis Syndrome
Harvard Health. edu Ask Dr. Rob about Piriformis Synddrome
Orthopaedic Research Novel model for the induction of postnatal murine hip deformity