Causes, symptoms and treatment of piriformis syndrome

Due to the fact that the sciatic nerve passes next to the piriformis muscle, when it contracts excessively, compression of the nerve is possible, which leads to intense pain from the buttock to the foot. The main task of the doctor at the initial appointment is to determine the causes of the spasm, search for the main source of pain (the tense piriformis muscle itself, compressed sciatic nerve, sacroiliac joint, pelvic organs, bone pathology) and develop the correct treatment algorithm.

Causes of the disease.

When the first symptoms appear, we often wonder why this happened to us. Often we do not perform unusual actions, do not lift extremely heavy loads, and do not spend the whole day in a forced position.

In fact, each of us has an adaptive reserve of the body, thanks to which for a long time we do not notice excess tension in the muscles, which can work at the limit of their capabilities for years. But there comes a moment when the muscle tells us in the language of pain: “master, I can no longer work in this mode.” A muscle spasm accompanied by pain is a muscle’s cry for help.

The cause of pain may be one awkward movement, but the history of the problem goes back to the distant past, because previously we simply did not notice tension in the muscle and could not take preventive measures to prevent clinically significant pathology. Therefore, it is more advisable to first consider the prerequisites for the appearance of excessive tension in the piriformis muscle, and then the immediate causes of the appearance of piriformis muscle syndrome.

Knowing the function of a muscle allows you to identify potential conditions that may lead to overuse of the muscle, called risk factors. The piriformis muscle is involved in external rotation of the leg, that is, the outward rotation of the forefoot when the leg is straightened.

If you bend your leg at the hip joint 90 degrees, this muscle will be involved in hip abduction, that is, moving the knee outward. The piriformis muscle is one of the main stabilizers of the hip joint, preventing excessive movement when moving on slippery and inclined surfaces and rough terrain.

Main risk factors for developing piriformis syndrome

1. Flat feet. With longitudinal flatfoot, the medial (inner) arch of the foot becomes flattened, which leads to pronation (internal rotation) of the forefoot. We remember that the piriformis muscle turns the leg outward, that is, with flat feet it is forced to take on a large load, counteracting the forces tending to turn the foot and the entire lower limb inward. Since flat feet are extremely rarely symmetrical, the piriformis muscle on the side of the more flattened foot is more susceptible to spasm.
2. Shortening the leg. Functional or anatomical shortening of the lower limb leads to an asymmetrical position of the pelvis and the appearance of a functional block in the sacroiliac joint. To compensate for impaired body statics and stabilize the pelvis, the piriformis muscle on the side of the shortened limb is forced to be in a state of greater tension, which serves as a prerequisite for the occurrence of piriformis muscle syndrome.
3. Scoliotic deformity of the spine. The formation of scoliotic arches of the spine inevitably affects the position of the pelvis and sacrum, which is accompanied by asymmetric tension in the muscles of the trunk and lower extremities and is a prerequisite for the occurrence of muscular-tonic syndromes of various localizations.
4. Coxarthrosis. Osteoarthritis of the hip joint leads to a reflex spasm of the muscles involved in the movement of the femur relative to the pelvis. Since the piriformis muscle is a stabilizer of the hip joint, it inevitably contracts and can lead to the development of piriformis syndrome.
5. Pathology of the pelvic organs. Any volumetric processes in the pelvic area (tumors, aneurysms, abscesses) can lead to the formation of a reflex spasm of the piriformis muscle. This must be remembered in the presence of concomitant complaints and symptoms from the pelvic organs, as well as in case of atypical manifestations of piriformis syndrome.

Immediate causes of piriformis muscle spasm (you may recognize yourself in one of the situations presented)

• an attempt to prevent a fall (slipped on a slippery surface, miraculously maintained balance, did not fall, but a few hours later pain appeared in the sacrum);
• staying in a forced position for a long time, standing with legs wide apart, performing physical activity (unloading goods to stabilize the pelvis with legs wide apart, moving the load from top to bottom, at first I felt tension in the lower back and pelvis, then pain appeared in the buttock);
• monotonous performance of repeated unusual actions to which the person was not adapted (planted/digged potatoes at the dacha, decided to finish everything in one day, and the next morning felt severe pain in the buttock);
• strong intense muscle contraction at a high pace under changed conditions (I used to run on a track in the gym, everything was fine, but I decided to run through the forest and the next day pain appeared in the thigh and buttock);
• long stay in the position of bending the legs in the hip joints with the knees apart (there were no problems with the pelvis throughout the pregnancy, but after a long labor I could barely get up from the couch, walked and dragged my leg, there was pain in the buttock and radiated to the leg);
• direct injury to the gluteal region (after the accident, fortunately, I did not receive any serious injuries; the impact was from the driver’s side; I did not feel it immediately, but after a couple of days I began to experience pain in the gluteal region);
• long-term fixed position of the leg (I decided to go with my family to Sochi by car in order to save time, I decided to drive without stopping, I sat behind the wheel for 18 hours, I get out of the car, and it’s like my leg is not mine, it’s numb and hurts).

Clinical picture

Manifestations of the syndrome include a whole range of disorders:

• local symptoms;
• signs of sciatic nerve compression;
• clinical picture of vascular compression.

Local manifestations include the following:

1. Drawing and aching pain. It is located in the buttock, sacrum, and hip joint. The pain increases in a vertical position, with movement, with adduction of the hip. It progresses when a person squats.
2. Vilenkin sign. In this case, discomfort appears during percussion. It is localized in the area of ​​the piriformis muscle.
3. Reducing pain in a horizontal position. It also decreases if a person sits with his legs apart.
4. Bonnet-Bobrovnikova sign. When the large gluteal muscle is completely relaxed, a compacted piriformis muscle is felt underneath it. When pulled, it causes pain.
5. Discomfort in the ischial spine. It is this area that the finger feels when quickly moving from the ischial tuberosity straight up.

Quite often, tonic tension of the piriformis muscle is complemented by the same condition of other muscle tissues of the pelvic floor. Almost always the deviation is accompanied by unexpressed sphincter deviations. In this case, there is a delay in the onset of urination.

When the sciatic nerve and vessels of the infrapiriform region are compressed, the following symptoms occur:

1. Dull pain. In this case, a vegetative coloration is observed, which manifests itself in the form of chilliness, decreased sensitivity or burning in the affected area.
2. Distribution of pain throughout the lower extremities. It mainly passes through the area of ​​​​innervation of the peroneal and tibial nerves.
3. Weakening of the Achilles reflex. A person experiences a deterioration in surface sensitivity.
4. Symptoms worsen when exposed to stressors or heat. Also, the clinical picture may intensify when the weather changes.

If the abnormal process predominantly involves the fibers that form the tibial nerve, discomfort affects the posterior group of muscle tissues of the lower leg. It occurs when walking.

When the blood vessels are compressed, a sudden spasm of the lower limb occurs, which provokes lameness. In such a situation, a person is forced to stop while moving. Dermanogi acquires a pale tint. After resting, the person can continue to move, but soon the attack recurs.

How to treat piriformis syndrome.

Drug treatment.

To reduce the severity of muscle spasms, muscle relaxants (mydocalm, sirdalud, baclofen) are traditionally prescribed. In case of severe pain, non-steroidal anti-inflammatory drugs (diclofenac, airtal, meloxicam, movalis) can be used, as well as drug blockade of the piriformis muscle (local anesthetics, hormonal drugs, vitamin B12).

The use of drug treatment is justified as an emergency treatment for the relief of acute pain. The main treatment should be aimed at modifying risk factors and eliminating the immediate causes of piriformis muscle spasm.

Physiotherapy.

Traditionally, laser therapy (HILT), magnetic therapy, and phonophoresis with hydrocortisone are prescribed for piriformis syndrome. One of the most effective physiotherapeutic methods is shock wave therapy.

Surgical intervention.

According to modern data, surgical treatment for piriformis muscle syndrome is of questionable effectiveness. Today it has been almost completely abandoned.

Manual therapy.

Manual therapy can be used to mobilize the sacroiliac joint. Also in the arsenal of a chiropractor there are techniques for post-isometric relaxation of the piriformis muscle, which are more effective than self-stretching the muscle.

Physiotherapy.

Physical therapy is indicated for all patients with piriformis syndrome as an important addition to the treatment prescribed by the doctor. Exercises to relax the piriformis muscle consolidate the therapeutic effect and, when performed regularly, serve to prevent the occurrence of repeated episodes of pain.

Pathogenesis

The narrow part of the piriformis muscle is fixed on the greater trochanter of the femur, and the wide part is attached to the sacrum. It is responsible for external rotation and helps to abduct the hip inward. This part of the muscle tissue passes through the sciatic foramen. Nerves and blood vessels are located in this area.

Due to the constant contraction of muscle tissue, the size of the infrapiriform opening decreases. As a result, blood vessels and nerves are compressed. First of all, the sciatic nerve is affected, which leads to severe pain.

In addition, compression of blood vessels disrupts blood circulation in the nerve trunk. This is considered an additional factor in the development of sciatica.

Secondary pathology

Secondary syndrome is associated with the influence of external factors. These include the following:

1. Traumatic injury to the buttocks. It can cause inflammatory damage to soft tissues, muscle spasms, and a combination of both. As a result, compression of the nerve occurs.
2. Direct damage to the piriformis muscle, postoperative injuries, increased stress on the lower back. Under the influence of these factors, muscle spasms appear.
3. Shortening of muscles. The syndrome is caused by changes in the biomechanics of the leg and lumbosacral region. This often causes compression and irritation of the sciatic nerve.

Secondary pathology is associated with microtraumas. They appear due to overuse of the piriformis muscle. These include long distance movement or direct impact.

Diagnostic methods

It is important to differentiate the pathology from sciatic neuropathy and deep-seated piriformis muscle. For this purpose, clinical tests are carried out. The basic ones are:

Consultation with a neurologist with collection of anamnesis and determination of neurological status. There is pain on palpation of the sacroiliac joint and the ventromedial surface of the greater trochanter. You can provoke discomfort with a number of tests:

• Attempting to raise the knee on the healthy side.
• Passive internal rotation of the hip.
• Active internal rotation of the flexed hip.
• Bend your torso forward with straight legs.

Instrumental diagnostics include assessment of the condition of the leg muscles and conductivity of the sciatic nerve. Electronography is used for this. To establish pelvic asymmetry, injuries, and malignant neoplasms, radiography of the pelvic bones, ultrasound of the pelvic organs, MRI and CT of the spine are necessary. It’s easy to view the addresses of diagnostic centers in the capital and clarify the cost of prescribed procedures through the “Unified registration center for MRI/CT/ultrasound in Moscow.”

Additionally, you may need to consult an oncologist, vertebrologist, gynecologist, or urologist. When making a diagnosis, it is important to distinguish between piriformis syndrome and lumbosacral plexitis, radicular syndrome due to herniated disc, and toxic damage to the sciatic nerve. If the pathology is accompanied by intermittent claudication, it is necessary to exclude:

• Obliterating endarteritis of the lower extremities.
• Obliterating atherosclerosis.

How can you relieve pain during exacerbation?

Mechanical overload of the muscle should be avoided. It is possible to correct asymmetry caused by inequality in the length of the lower limbs by using a special heel on shoes. You can correct the asymmetry caused by a decrease in the size of one half of the pelvis by using a pad under the buttock. It is important to restore movement in the sacroiliac joint.

Choosing the right sleeping position is of great importance. When sleeping on the side, the patient should place a pillow between the knees to support the leg. Frequent changes of sitting position are necessary; you can use a rocking chair. Stops should be arranged during long driving periods - for short walks.

It is necessary to perform a set of exercises aimed at stretching the muscles, which include ischemic compression of trigger points. but it is very important to avoid compression of the nerves, so the exercises should be supervised by a specialist.

Treatment

The piriformis muscle is located deep in the gluteal region. It is impossible to remove trigger points in it using classical massage techniques. The main treatment for problems caused by the piriformis muscle is manual therapy. In the presence of secondary disorders caused by pathology of the piriformis muscle, separate correction is required. Thus, neurovascular disorders in the affected limb, caused by compression of the vessels supplying the sciatic nerve, require the prescription of drugs that improve blood circulation. Depending on the severity of vascular disorders, drugs can be prescribed intravenously or in tablets. If the problems of the piriformis muscle are caused by a violation of its innervation, autogravitational traction of the spine is necessary.

As accompanying methods that accelerate the normalization of muscle tone and blood supply to the sciatic nerve, acupuncture, hirudotherapy, and some physiotherapeutic techniques are used. After pain relief, it is necessary to regularly perform special exercises for a long time to maintain normal muscle tone and form the correct pattern of movements.