Piriformis is one of the lesser known muscles of the hip joint although any trainer at your local gym should of know it´s importance. Along with the Gemelli, Obturator and Quadratus Femoris muscles, the Piriformis is a short muscle forming the core of the hip external rotators. Consider the position of a hurdler; these are the muscles which provide the stability for external rotation of the hip joint when the leg is positioned away from the body.
These muscles are not big prime movers .The larger Glutei, Adductor and Abductor muscles (buttocks and thigh) provide the force required to run, jump and charge upstairs but the Piriformis is an important hip joint core muscle controlling the finer points of hip angulations.
We are looking at this picture from the back of the hip joint.
The Obturator and Gemelli cross over the hip joint at a lower level to Periformis and while they can control the rotation they are not strong abductors (moving the leg out to the side)
The Gluteal muscles have a much better angulation of attachment to bring about the abduction movement and also to perform external rotation.
Periformis however is perfectly attached to perform both movements together. Abduction of the thigh with external rotation of the hip … hurdler´s position.
You may well question why your Piriformis may be the cause of your pain when you do not regularly jump hurdles. In fact we perform this movement quite often without even being aware of it but in a much smaller range, for example, getting in and out of a car or stepping over an obstacle or fence.
Most of us will rarely put this muscle through it´s full range of stretch on a daily basis and so it can become tight and shortened giving rise to symptoms with no history of trauma at all.
Causes of Periformis Injury
Almost any sport requiring a twist and abrupt changes of direction may give rise to a Periformis injury ( rugby, tennis, squash ) as can prolonged exercise such as long distance running and overtraining in the gym. We can also include trauma such as a fall pulling the leg away from the body (skiing or skating)
Signs and Symptoms
Deep pain in the top of the buttock.
Pain may extend down the back of the thigh.
There may also be tingling or numbness down the back of the thigh and in more severe cases, possibly as far as the foot.
Symptoms will worsen with prolonged sitting and when the legs are apart in the sitting position but may be relieved with walking.
The above symptoms I have described are very similar to sciatic nerve pain and this is why correct diagnosis is all important..
The sciatic nerve emerges from the pelvis alongside the Periformis and in some people may actually pass through this muscle and so it is possible that any injury to Periformis can be mistaken for sciatica.
Sciatica is most commonly caused by an irritation of the sciatic nerve where it exits the spine from the last few vertebrae in the spinal column (L4, L5, S1) Compression or irritation of the sciatic nerve from this source can be caused by many conditions such as herniated discs, spondylolysthesis, arthritis, osteophytes, postural anomalies ….
Sciatic nerve symptoms caused by injury to the Periformis muscle is known as
Periformis Syndrome, an irritation of the sciatic nerve, the cause of which has evolved outside the spinal column.
Diagnosis may require X ray or MRI scan to rule out the possibility of a discal herniation.
Physiotherapy will required to help heal a damaged Periformis which may include deep tissue massage, passive stretching, ultrasound and interferential diathermy or TNS.
It is most important to learn the correct stretching techniques.
The Physiotherapy Centre
+34 609 353 805