Piriformis Syndrome

What is Piriformis Syndrome?

Piriformis syndrome is a condition in which the piriformis muscle, a small muscle deep in the buttock that rotates the hip outward, irritates the sciatic nerve running beside it and causes sciatica-like pain.^[1] It is a relatively uncommon cause of sciatica, and it remains controversial because the diagnosis rests on history and examination rather than a definitive test.^{[2, 3]}

Common symptoms

The typical symptom is pain in the buttock that may ache or burn, and may shoot down the back of the leg. Numbness and tingling along the path of the sciatic nerve are not unusual.^[1]

• Tenderness over the deep buttock
• Pain that gets worse with sitting
• Pain that increases with movements that stretch or tighten the piriformis muscle, such as turning the hip inward^[3]

Causes and risk factors

Most cases are thought to be secondary, following an injury, overuse or other insult to the muscle. A smaller number are primary and related to a variation in anatomy.^[4] Muscle spasm after overuse or a fall, long periods of sitting, and repetitive hip movement in running or cycling are commonly listed contributors, though not all of these have been well tested.^[1]

How it is diagnosed and treated conventionally

Piriformis syndrome is a clinical diagnosis, and several other problems can mimic it, including lumbar canal stenosis, disc inflammation and pelvic causes.^[1] Some reviewers think it is over-diagnosed and that a spine or pelvic source should be considered first.^[5] Imaging is mainly used to look for those other causes.^[2]

Treatment usually starts with conservative care such as medicines, physical therapy and activity changes. When these fail, injections of steroid or botulinum toxin and dry needling may be tried. Endoscopic release surgery is considered only when other approaches have not worked.^[4]

Why Piriformis Syndrome calls for a whole-person approach

Piriformis syndrome rarely has a single cause. A tight muscle, an irritated nerve, how you sit and move, and other sources of pain in the spine or pelvis can all play a part, so the cause of buttock pain is often hard to pin down.^{[1, 5]}

Care that looks at several of these factors is a reasonable addition to the treatment your physician directs. The factors below are the ones most often discussed.

Muscle tension and overuse

Spasm or tightness in the piriformis after overuse or injury is the most commonly described mechanism, and the muscle can then press on the nerve beside it.^[1] Stretching and physical therapy form the base of conservative care.^[4]

Sitting, posture and hip mechanics

Sitting tends to aggravate the pain, and it is one of the most consistently reported features of the condition.^[3] Changes in movement habits and the balance of muscles around the hip and pelvis are therefore part of a sensible plan.

Nerve irritation and inflammation

Sciatic-type pain is largely driven by inflammation that irritates the nerve, while direct compression more often causes weakness.^[6] Pain from an irritated nerve is a form of nerve-related (radicular) pain, a type of neuropathic pain.^[7]

Other sources of buttock and leg pain

The spine, hip and pelvis can produce similar symptoms, which is why medical evaluation matters.^{[1, 5]} We do not make this diagnosis.

Acupuncture for Piriformis Syndrome

What the research shows

The evidence for acupuncture in piriformis syndrome itself is limited. A PubMed search found no systematic review of completed trials, and most trials were small, done in China and compared one needling method with another or with an injection, not with sham acupuncture.

In one trial of 60 patients, trigger-point acupuncture and a glucocorticoid injection gave similar results at one month. At two and three months, the acupuncture group had less pain, better function and lower analgesic use. No serious adverse effects occurred in either group.^[8] Trials of 100 and 80 patients found that elongated-needle techniques or needling at tender points was more effective than routine acupuncture point selection, but they had no sham or untreated group.^{[9, 10]}

A trial of ultrasound-guided dry needling in 32 patients, a related technique, found less pain at one week than a waiting list.^[11] A review of dry needling for myofascial back pain reported decreased pain and disability, and asked for better long-term studies.^[12]

Studies of acupuncture for sciatica of other causes add indirect support. A meta-analysis of 28 trials with 2,707 participants found acupuncture outperformed pain medicines for sciatica and called for more rigorous studies.^[13] A sham-controlled trial of 216 people with chronic sciatica from a herniated disc found less leg pain and better function with real acupuncture, with the effect lasting 52 weeks.^[14] Those results may not carry over to piriformis syndrome, which has a different source.

How acupuncture may work

Researchers propose that acupuncture for radicular pain relaxes muscle spasm, improves small-vessel blood flow, lowers the release of inflammatory molecules, and changes how the spinal cord and brain process pain.^[7] These are proposed explanations, not settled facts, and have not been shown specifically in piriformis syndrome.

What treatment involves

Treatment uses fine, sterile, single-use needles placed in the buttock, hip, lower back and leg, usually left in place for about 20 to 40 minutes. The trials above used from two treatments one week apart up to ten treatments every other day, and a typical course involves several visits with reassessment.^{[8, 9]}

Serious problems are rare. In prospective studies, about 9 in 100 patients had a minor reaction such as brief bleeding, soreness or redness at a needle site, and serious events occurred in about 1 in 10,000 patients.^[15] Tell the practitioner first if you have a bleeding disorder, take blood thinners, are pregnant, or have a pacemaker (relevant to electroacupuncture).

Ayurvedic medicine for Piriformis Syndrome

The Ayurvedic view

Ayurveda has no classical name for piriformis syndrome. Sciatic-type pain that travels down the leg is described as Gridhrasi, named after the vulture-like walk of a person in pain, and is understood as a disorder of Vata, the principle said to govern movement.^[16] These are traditional categories, not biomedical diagnoses.

Therapies that may be used

Care is chosen for the individual and traditionally combines:

• Diet and daily routine intended to calm Vata, such as warm, regular meals and steady sleep hours
• Warm oil massage over the buttock, hip and leg, with local heat
• Herbs such as nirgundi (Vitex negundo) and guggulu-based formulas, prescribed individually by a practitioner^{[16, 17]}
• Gentle stretching and breathing practices within your physician's guidance

Herbal preparations applied to the skin (transdermal medication therapy) may be considered for local muscle tension. We make no claim of benefit for it. Panchakarma procedures, including medicated enema (basti), are not appropriate during pregnancy, acute illness or frailty, or before red-flag symptoms have been medically assessed.

What the research shows

There are no clinical trials of Ayurvedic treatment for piriformis syndrome that we could find. The research on Gridhrasi, which is closer to sciatica, is very limited. One study of 102 patients reported that symptoms improved with a nirgundi extract and improved more when a small oil enema was added, but there was no placebo or untreated group.^[17] A single-group study of 40 patients given a guggulu formula for 30 days reported mild improvement in about half and moderate improvement in about a third.^[16] Studies without a comparison group cannot show that a treatment caused the change.

Herbal medicine for Piriformis Syndrome

Herbs and formulas that have been studied

No herbal treatment has been tested in piriformis syndrome that we could find. The closest research is on Western herbs for non-specific low back pain, including devil's claw, white willow bark and cayenne (capsicum) applied to the skin.^[18] Chinese and Ayurvedic herbs are traditionally used for muscle and nerve pain, but we have no piriformis studies to cite.

What the research shows

A Cochrane review of 14 trials of herbal medicine for non-specific low back pain found moderate-quality evidence that capsicum cream reduces chronic low back pain more than placebo, and low to moderate-quality evidence for short-term pain relief with devil's claw and white willow bark. Whether this applies to buttock pain from the piriformis is not known.^[18]

Safety and herb-drug interactions

Herbs are active substances and can interact with medicines. Case reports describe bleeding when warfarin was combined with herbs including dang gui (Angelica sinensis), dan shen (Salvia miltiorrhiza), ginger and Boswellia.^[19] People taking blood thinners need a practitioner's review before using any herb for pain.

In one study, about one fifth of Ayurvedic products bought online contained detectable lead, mercury or arsenic.^[20] Herbs should come from tested sources and be prescribed individually. Tell us if you are pregnant or breastfeeding, have liver or kidney disease, or have surgery planned.

Translating traditional medicine into modern biological language

The links drawn here are interpretation, not equivalence. Chinese medicine describes pain in the buttock and leg as blocked flow of qi and blood in the channels, often with cold, damp or injury. Researchers studying acupuncture for nerve-related pain measure things that loosely parallel this picture: muscle spasm, local blood flow, inflammatory signaling and pain processing in the nervous system.^[7]

Ayurveda's aggravated Vata describes sharp, shooting pain that limits movement.^[16] No study has shown that a dosha corresponds to a specific biological process.

How this care fits with your medical care

Integrative care for piriformis syndrome is complementary. Keep your physician, physical therapist or pain specialist, and do not stop or change prescribed medicines or injections without your prescriber. We do not diagnose the cause of buttock or leg pain, so new or worsening symptoms should be medically evaluated.

Please bring your diagnosis, any imaging reports, a full list of medicines and supplements, and details of any injections or surgery, planned or past.

When to seek urgent medical care

Some symptoms point to severe nerve compression or another serious cause that needs prompt assessment.^[6]

• New trouble passing urine, or loss of bladder or bowel control
• Numbness in the groin, genitals or inner thighs (the "saddle" area)
• Leg weakness that is new or getting worse, such as a foot that drags
• Severe pain, numbness or weakness in both legs
• Buttock or back pain with fever, unexplained weight loss or a history of cancer
• Symptoms that begin after a serious fall or accident

If any of these occur, call 911 or go to the nearest emergency department.