Piriformis muscle


German name: pear-shaped muscle


The piriformis muscle is a pear-shaped muscle that belongs to the deep hip muscles.
It helps, among other things, the external rotation, the splaying and moving the leg backwards.

Course of the piriformis muscle

Of the Piriformis muscle arises on the inner surface of the Os sacrum (sacrum), more precisely from the foramina sacralia anteriora (sacral holes) one to four.

In addition, some fiber strands arise from:

  • the upper edge of the major ischial notch
  • from Sacrotuberous ligament
  • of the Articulatio sacroiliaca

It then runs through the greater ischiadic foramen (ischial hole) and attaches to Thigh bone, more precisely on the inside of the apex of the Major trochanter (Tip on the large rolling mound).
This is where the muscles come from Musculi gemelli and Obturator internus muscle together.

Illustration piriformis muscle

Illustration of the piriformis muscle: pelvis from behind (A) and from the side (B)

Piriformis muscle

  1. Pear-shaped muscle -
    Piriformis muscle
  2. Iliac scoop -
    Ala ossis ilii
  3. Posterior sacrum holes -
    Foramina sacralia posteriora
  4. Sacrum -
  5. Great Rolling Hill -
    Greater trochanter
  6. Small rolling hill -
    Lesser trochanter
  7. Femoral shaft -
    Corpus femoris
  8. Ischium -
    Os ischii (ischium)
  9. Fifth lumbar vertebra -
    Vertebra lumbalis V

You can find an overview of all Dr-Gumpert images at: medical illustrations


Piriformis muscle pain

The piriformis muscle runs in close proximity to the exit point of the sciatic nerve from the inside of the pelvis to the back of the buttocks. In some people, the sciatic nerve pulls through the piriformis muscle, which promotes the development of sciatic pain through this muscle. If the piriformis muscle shortens or thickens, for example due to incorrect or insufficient training or limited mobility of the hips due to joint problems, the sciatic nerve is compressed and either pressed against the bony pelvis or pinched in the muscle fibers.
This pressure on the sciatic nerve causes so-called pseudoradicular pain, which is pain that is very similar to the symptoms of a herniated disc, but is not caused by a problem with the intervertebral discs. Pain caused by the pressure of a thickened piriformis muscle on the sciatic nerve or the entrapment of nerve fibers in the thickened piriformis muscle is also known as piriformis syndrome.
Overloading or poor posture can also trigger the piriformis syndrome through an inflammatory reaction. The inflammation of the piriformis muscle can lead to an accompanying inflammation of the surrounding tissue. Since the sciatic nerve is close to the piriformis muscle, it can also be affected by this inflammatory reaction and transmit pain impulses to the brain. Sharp pain in the lumbar spine and deep buttocks can be symptoms as well as long-lasting pain that radiates into the leg on the affected side or a tingling sensation that spreads over the buttocks and back thigh. In severe cases, standing on tiptoe and heels may be restricted.
Piriformis syndrome can cause pain when climbing stairs, cycling, jogging or lying on the sick side. Sitting for long periods of time can also increase the pain, because in a sitting position not only does the piriformis muscle irritate the sciatic nerve, but the weight of the body also leads to additional compression of the sciatic nerve. Crossing your legs while sitting makes the pain worse.

Read more on the subject below Symptoms of Piriformis Syndrome.

Piriformis Syndrome Test

Unfortunately, there is no test to detect piriformis syndrome that can prove with one hundred percent certainty that the pain is caused by the piriformis muscle. However, there are various tests for piriformis syndrome that can be combined with high probability lead to proof or exclusion of the syndrome.
The so-called FAIR test If the patient lies on the healthy side, the leg below is stretched out straight and the upper body is as flat as possible on the examination table. The leg on the painful side is pulled towards the body with the knee bent so that the hip is flexed 60° amounts. Additionally this leg will adducted and internally rotatedThe knee is oriented towards the examination table. The examiner now pushes the overlying leg further down towards the couch and thus releases one strain of the piriformis muscle. Pain in the buttocks during this examination indicate piriformis syndrome. The FAIR test is also positive if, in the examination position, pain in the buttocks can only be triggered by pressing the buttocks over the area of ​​the piriformis muscle. The FAIR test is a very sensitive and specific test for the piriformis muscle, but it can of course also be positive for other diseases of the lower back and buttocks.

Read our topic for more information Tests for Piriformis Syndrome.


The piriformis muscle runs from the Sacrum to the greater trochanter of the Thighbone. Regular stretching can relieve pain caused by the piriformis muscle. The stretching exercises relax the pelvic area and the pressure from the tense piriformis muscle is released. The piriformis muscle acts in the External rotation of the leg, but can also be used with Spreading the thigh or the leg backwards to lead.
The best way to stretch it is to assume a position achieved by movement mediated by the piriformis muscle. One option is to sit on your knees and then stretch one leg back so that the kneecap touches the floor. This position will stretch the piriformis muscle and should be held for about a minute. There are 2-3 repetitions per side.
Another stretching exercise is done lying on your back. The knees are bent so that the soles of the feet are firmly on the floor. Then one leg is pulled towards the upper body and one foot is brought to the knee. The leg to be stretched crosses so the other leg. Now push the knee of the leg to be stretched away from the body and hold the position for about a minute. Here, too, 2-3 repetitions are useful.

Exercise the piriformis muscle

The piriformis muscle conveys a through its contraction External rotation, Abduction (Splaying) and Extension (Extension) in the hip joint. All of its functions are used well by both large and small Glutes exercised, which is why special training is difficult only for the piriformis muscle. Strengthening exercises that use the entire Strengthen the buttocks muscles and thus prevent functional impairment of the piriformis muscle. Exercises are also recommended for the Abductor group of the thigh as well as exercises for the Hip muscles, as these muscle groups stabilize the pelvis and correct bad posture, which can also be a cause of piriformis syndrome.


As mentioned briefly above, the small piriformis muscle many functions.

  • turns the leg outwards (External rotation)
  • stretches the leg (Extension)
  • spreads it to the side (Abduction)
  • and leads him backwards (Retro version)


He is nervously supplied Piriformis muscle from Sacral plexus.
The sacral plexus is a plexus of nerves in the sacrum and is made up of the L5 and S1 nerves.


The great Sciatic nerve runs between the Piriformis muscle and the pelvic bone in the infrapiriforme foramen.
In the event of an accident, the Sciatic nerve through the M. piriformis and thus to Piriformis Syndrome come.
A rarely known phenomenon is the L5 / S1 in a herniated disc Trendelenburg sign can come.
In the case of a herniated disc caused by an L5 / S1, most medical professionals think directly of problems with the lower legs, i.e. the foot levers (M. tibialis anterior = anterior tibial muscle, extensor hallucis longus) and core of the foot (M. gastrocenmius = calf muscle / twin muscle).
The Trendelenburg sign arises from the paralysis of the piriformis muscle and the resulting inability to stand on one leg, as the pelvis can no longer be sufficiently abducted. The consequence of this paralysis is a waddling gait.

Piriformis Syndrome

Muscles have to be innervated by nerves, i.e. controlled. In the case of the piriformis muscle, this happens via direct nerves from the Sacral plexus. The sacral plexus is a large plexus of nerves that lies on the sacrum.

Piriformis syndrome describes one Narrowing of the sciatic nervewhich runs through the infrapiriforme foramen. The sciatic nerve comes from the sacral plexus and supplies the hip, thigh, lower leg and foot muscles. Can cause the constriction jerky, vigorous movements of the hip, one wrong posture, an injury or even long periods of sitting be.

It comes to as a result severe lower back pain, in the buttocks and in Thigh. In some cases, it even extends into the groin, on the front of the body. Also Sensory disturbances such as tingling or numbness are possible. The symptoms often occur when the hips are rotated, i.e. when you turn your upper body to the side or turn over in bed.

Treatment usually consists of one Exercise therapy, stretching and Exercises to build strength in the muscles of the buttocks and thighs. In addition, massages and in extreme cases anti-inflammatory pain relievers how ibuprofen help. You can treat the pain relatively easily, effectively and cheaply and thus reduce it. Nevertheless, the therapy should be taken seriously, as it can otherwise lead to serious consequences such as difficulty walking.