Ather Bios Clinic – Bridgefords’s Best Bites
The term was introduced by Robinson in 1947, implies a group of signs and symptoms caused by piriformis muscle disorders, leading to irritation and compression of the anatomic structures passing under its belly, notably the sciatic nerve, causing sciatica that is not related to the spine or discs. There is no consensus regarding diagnosis, pathophysiology, investigation and management.
Anatomy: There are 2 piriformis muscles located across the bottom, attaching at one end to the ball at the top of the hip bone (the greater trochanter of the femur) and at the other end to either side of the sacrum (the triangular bone at the base of the spine) where the utero-sacral ligament also attaches. Piriformis muscles pass over the sacro-iliac joints, having a strong relationship with sciatic nerve, which passes under or through piriformis muscle slightly differently in each individual, making some people more susceptible to related sciatic nerve irritation.
Symptoms: Are mostly related to spasm of the muscle and irritation of the underlying sciatic nerve. Buttock tenderness in the muscle itself and deep seated gluteal pain, which can radiate to coccyx and back of the leg. Aggravated by prolonged sitting, hip flexion, abduction (taking the leg out to the side) and internal rotation. There may be different leg lengths, weak hip abductors and pain on resisted hip abduction in sitting position.
Causes: Usually by a fall on the buttocks or direct trauma. Can also be from irritation of the sacro-iliac joint or a lump near the sciatic notch, lipoma (fat containing lump) in the muscle, chronic expanding hematoma across the gluteal muscles, fibrosis after a deep injection, one leg shorter than the other, pyomyositis (bacterial infection in skeletal muscle that can cause a pus-filled abscess), dystonia (neurological movement disorder causing contractions and spasms), possibly adverse effects of atorvastatin. The layer of fascia surrounding the abdominal cavity can provide a route for infection from pelvis to piriformis, involving it in urino-genital irritation. Piriformis syndrome after caesarean section spinal anaesthetic is attributed to the spinal procedure, though can be caused by prolonged upright sitting after delivery, compressing sciatic nerve at sacro-iliac joint, inflaming and irritating piriformis. Ballet dancers often need help with piriformis due to leg turn-out position.
Diagnosis: Neurological examination and imaging results are usually normal and used to rule out other causes of sciatica; each leg can be lifted up when laying on the back; symptoms are not be relieved by lumbar facet joint injections as lumbar nerve origin sciatica would be. Flexion, adduction and internal rotation movements of the hip cause pain. Pain can be reproduce by deep palpation in piriformis; contracting piriformis with Pace’s manoeuvre: seated patient abducts the legs; stretching piriformis with Freiberg’s manoeuvre: forceful internal rotation of the extended thigh and Side-laying: patient laying painful side up, upper leg bent, then lifting and holding upper knee several inches off the table.
Treatment: Focuses on stretching (hip flexion, adduction, and external rotation), hip muscle strengthening, physical therapies, deep soft tissue work, acupuncture dry-needling, pain medication and ultrasound guided nerve blocks and injections, including corticosteroid and botulinum toxin; surgical management should be a last resort and can include arthroscopic release of the muscle.
Osteopathic/Manual Management: Adjusting spinal and hip bones, soft tissue and myofascial techniques, stretching, dry needling, home rehabilitation exercises; attention to postural habits and ergonomics.
We are happy to advise you on your health matters and offer a free 15 minute joint and spinal check, without obligation.
Lin Bridgeford DO KFRP MICAK MICRA FSCCO MSc
Registered Osteopath & Kinesiologist & Yoga Teacher
Aether Bios Clinic