Soft Tissue Techniques in Piriformis Syndrome

Piriformis syndrome is caused by prolonged or excessive contraction of the piriformis muscle. Because of the close proximity to the sciatic nerve, piriformis syndrome is associated with pain in the buttocks, hips, and lower limbs. Yeoman was the first to describe pain in the sciatic distribution to piriformis syndrome. Many synonyms for the condition are used in the literature, such as ''deep gluteal syndrome'' and ''pelvic outlet syndrome''. It has been suggested that piriformis syndrome is responsible for 5-6% of cases of sciatica. In the majority of cases, piriformis syndrome occurs in middle-aged patients (mean age 38 year). The ratio of female to male patients with piriformis syndrome has been reported as 6:1.

Three specific conditions may contribute to piriformis syndrome:

1. myofascial referred pain from trigger points in the piriformis muscle
2. adjacent muscles, nerve and vascular entrapment by the piriformis muscle at the greater sciatic foramen
3. dysfunction of the sacroiliac joint. Myofascial pain syndrome in the piriformis muscle is well recognized. Gluteal pain is reported to be observed in 97.9% of cases, pain (and paresthesias) in the back, groin, perineum, buttocks, hip, back of the thigh (81.9%),calf (59%),foot, in the rectum (during defecation), and in the area of the coccyx. Low back pain is reported to be observed in 18.1% of cases. Intense pain will occur when the patient sits or squats. Nevertheless, true neurologic findings are not usually present in piriformis syndrome and sensory deficits may be completely absent.

There is no gold standard in diagnosing piriformis syndrome. The physical examination may reveal several of the following well-described signs:

• The piriformis sign, (which presents as tonic external rotation of the affected lower extremity) is reported to be observed in 38.5% of the patients.
• Freiberg's sign involves pain on passive forced internal rotation of the hip in the supine position, thought to result from passive stretching of the piriformis muscle and pressure on the sciatic nerve at the sacrospinous ligament. This test is positive in 56.2% of the patients.
• Pace's sign consists of pain and weakness on resisted abduction and external rotation of the thigh in a sitting position . A positive test is reported to occur in 46.5% of the patient.
• Lasegue's sign involves pain on the affected side on voluntary adduction, flexion, and internal rotation.
• Beatty's maneuver is an active test that involves elevation of the flexed leg on the painful side while the patient lies on the asymptomatic side. Abducting the thigh to raise the knee off the table elicits deep buttock pain in patients with piriformis muscle but back and leg pain in those with lumbar disk disease.
• The Hughes Test (external isometric rotation of the affected lower extremity following maximal internal rotation) may also be positive in piriformis syndrome.
• Gluteal atrophy may be present.Sacroiliac tenderness is reported to be observed in 38.5% of the patients.

Piriformis syndrome causing sciatica usually responds to conservative treatments, including physical therapy, lifestyle modification, pharmacological agents (non-steroidal anti-inflammatory agents, muscle relaxants, and neuropathic pain medication) and psychotherapy. Physiotherapy management for piriformis syndrome includes application of heat therapy and ultrasound therapy in conjunction with stretching of piriformis muscle shows good effect on treatment. Also manual therapy approaches like myofascial release (MFR), muscle energy technique (MET), Active release technique shows beneficial effect on the treatment of soft tissue. The last option is surgical intervention which involves endoscopic decompression of sciatic nerve.

The Active release technique (ART) is a manual therapy used to recover function of soft tissue and in many ways similar to traditional 'Pin and stretch' techniques. Technique works on a variety of muscle, tendon, ligament, fascia and nerve tissues. In this technique deep pressure is applied over the tender point in a shortened position of the muscle and then patient is asked to actively take it in an opposite lengthened position. This will break the adhesions and restores the proper texture, elasticity and functions of soft tissues. There are a variety of studies that imply the value of ART as a treatment method for soft tissue injuries. ART has been used to treat nerve entrapment, tendinopathy, muscle strain, snapping hip syndrome, lateral epicondylitis, impaired range of motion, overuse syndrome, and improve performance and contributed to faster return to activity and decreased treatment time.

Muscle energy technique (MET) is an active muscle based treatment approach that involves the voluntary contraction of a subject's muscle(s) in a precisely controlled direction, against a counterforce provided by the therapist. The MET may be used to decrease pain, stretch tight muscles and fascia, reduce muscle tonus, improve local circulation, strengthen weak musculature and mobilize joint restrictions. The MET is used for achieving tonus release in a muscle before stretching via introduction of an isometric contraction to the affected muscle producing post isometric relaxation. Post isometric relaxation (PIR) is a MET used to relax and lengthen a hypertonic and shortened muscle. This gentle stretching technique is typically used on postural muscles. These muscles often become short and tight and can lead to muscle imbalances. This can limit range of motion and cause joint restrictions.

The effects of ART on gluteus medius for chronic lower back pain and concluded that ART was effective in reducing lower back pain.

ART for ITB syndrome and results showed that ART decreases pain and improves function.

The effects of Neuromuscular therapy and ART on piriformis tightness and concluded that significant improvement was observed in the VAS score and ROM in ART group.

Compared the effectiveness of ART with mulligan bent leg raise for hamstring tightness and concluded that ART was better in improving flexibility and ROM of hamstring.

Compared post isometric relaxation with stretching on piriformis syndrome and concluded that PIR technique group significantly improved in all outcome measures (pain, ROM).

The effects of PIR technique on myofascial tightness of lumbo-pelvic musculature in patients with chronic low back pain and concluded marked improvement in pain and functional disability.

Compared PIR technique with high velocity low amplitude techniques and concluded that both of the techniques are equally effective in managing low back pain.

Compared post isometric relaxation and reciprocal inhibition and concluded that post isometric relaxation is more effective in treating piriformis syndrome than reciprocal inhibition and proposed to follow further in chronic piriformis syndrome.

Currently there is little evidence of relative effects of Active release technique and post isometric relaxation in piriformis syndrome. Both techniques are found to be effective individually in different conditions but no research has been done yet on comparison of active release technique with muscle energy techniques like PIR in piriformis syndrome. Studies of ART on hamstring tightness shows significant immediate effects but the study was on healthy subjects. Effectiveness of ART is evident by one another study but only immediate effects were analyzed. Thus, effective long term follow up is lacking in literature. This present research will fill the gaps by studying the effects of ART and PIR in chronic piriformis syndrome and will help the clinicians with an alternative treatment approach