What is piriformis muscle?
The piriformis muscle is a small but important external rotator of the hip that crosses the sciatic nerve and is believed by some to cause sciatica-type pain when it compresses the nerve. However, the existence of this so-called "piriformis syndrome" remains controversial and diagnosis is difficult.
Controversy is due to the limited research about the condition and the difficulty of making the diagnosis, particularly as symptoms mimic many other more common diagnoses.
How common is it?
Piriformis syndrome may account for 0.3-6% of sciatic-like syndromes.
What causes it?
The sciatic nerve normally passes inferior to the piriformis muscle. Entrapment of the sciatic nerve may develop following trauma to the buttocks or piriformis muscle strain causing scarring and fibrosis around the nerve, or due to the structure of the piriformis, such as when branches of the nerve pass through a bifid piriformis muscle.
During downhill running or sprinting, the piriformis muscle undergoes eccentric contraction and some runners may develop the syndrome via this mechanism.
The activities involved may include running, where the gluteus medius and tensor fascia lata are activated in the stance phase, but more often sports requiring cutting and turning, which involve the external rotators of the hip (eg, piriformis, gluteus medius). The onset of pain is less acute but usually within 24 hours.
What are the symptoms?
The most common presenting symptom is buttock pain of gradual onset that increases with sitting. The "wallet sign" associated with the syndrome is when a male patient finds he can no longer sit on his wallet without causing symptoms. Paresthesias may develop, but the classic radicular symptoms of sciatica are not common.
Clinically, the diagnosis of piriformis syndrome is considered when the classic signs of a lumbar radiculopathy elicited by provocative testing are absent, neurologic examination is normal, and other causes of gluteal and sacroiliac pain are ruled out.
Can you test for it during physical examination?
A provocative test (Freiburgs test) suggesting piriformis syndrome is performed by placing the hip in extension and internal rotation, and then resisting external rotation. Pain or sciatic symptoms denotes a positive test . Another test (Pace sign) involves having the seated patient resist abduction and external rotation. Pain and reproduction of symptoms marks a positive test.
Are there any imaging tests?
When necessary, plain radiographs and MRI of the hip and pelvis are obtained to rule out other causes of symptoms. EMG and nerve conduction studies are rarely positive in piriformis syndrome but can be useful for eliminating other diagnostic possibilities.
What is the treatment?
Treatment begins with physical therapy involving strengthening of the pelvic and hip region and stretching of the piriformis. Physical therapy is effective in the majority of cases.
YouTube search shows same of the exercises: https://www.youtube.com/results?search_query=piriformis+syndrome+exercises Always consider consulting a professional before any treatment is started.
Ultrasound-guided glucocorticoid injections have been beneficial in some cases, and botulinum toxin injections have also been used. Surgery (typically a piriformis tenotomy) may be considered if symptoms are debilitating and persist despite conservative therapy.
Gluteus medius weakness and tendinopathy
The gluteus medius muscle originates along the external surface of the ilium and runs distally and laterally to its attachment on the greater trochanter of the femur. The gluteus medius abducts the hip and assists with pelvic stability during running. Weakness of the muscle causes pain with hip abduction and rotation. Pain generally increases when the muscle is stretched and there may be focal tenderness at the muscle's insertion, just medial and superior to the greater trochanter. Difficulty maintaining a level pelvis while standing on one leg is called positive Trendelenburg sign.
References:
https://www.uptodate.com/contents/overview-of-running-injuries-of-the-lower-extremity
https://www.uptodate.com/contents/approach-to-hip-and-groin-pain-in-the-athlete-and-active-adult
