Symptoms, Causes of Piriformis Syndrome is a neuromuscular condition characterized by hip and buttock pain. This syndrome is often overlooked in clinical settings because its presentation may be similar to that of lumbar radiculopathy, primary sacral dysfunction, or innominate dysfunction. The ability to recognize piriformis syndrome requires an understanding of the structure and function of the piriformis muscle and its relationship to the sciatic nerve. The authors review the anatomic and clinical features of this condition, summarizing the osteopathic medical approach to diagnosis and management. A holistic approach to diagnosis requires a thorough neurologic history and physical assessment of the patient based on the pathologic characteristics of piriformis syndrome. The authors note that several nonpharmacologic therapies, including osteopathic manipulative treatment, can be used alone or in conjunction with pharmacotherapeutic options in the management of piriformis syndrome.[Rx]
Piriformis syndrome (PS) is a painful musculoskeletal condition, characterized by a combination of symptoms including buttock or hip pain due to compressed and/or irritated sciatic nerve by the piriformis muscle as it passes deeply through your buttock, resulting in pain. It is an uncommon neuromuscular disorder that is caused when the piriformis muscle compresses the sciatic nerve.[Rx]
Piriformis syndrome is an often misdiagnosed cause of sciatica, leg, or buttock pain, and disability. The sciatic nerve may be compressed within the buttock by the piriformis muscle, with pain increased by muscular contraction, palpation, or prolonged sitting. A thorough medical history and physical examination are essential to proper diagnosis. Diagnostic testing may be used to differentiate piriformis syndrome from other causes of sciatica, lower extremity weakness, and pain. This article reviews the pathophysiology and management of piriformis syndrome.
The piriformis is a flat, pyramid-shaped muscle that lies parallel to (in line with) the gluteus medius muscle’s back margin and underneath the gluteus maximus muscle in the hip area.
Pain in your buttocks and radiating sciatic pain is sometimes the result of piriformis syndrome, or tightening and irritation of the piriformis muscle.
Anatomy of Piriformis Syndrome
- Inferior to piriformis
- Superior to superior gemellus
External rotators of the thigh include (superior to inferior)
- Superior gemellus
- Obturator internus
- Inferior gemellus
- Obturator externus
- Quadratus femoris
Causes of Piriformis Syndrome
- Muscle spasm in the piriformis muscle, either because of irritation in the piriformis muscle itself, or irritation of a nearby structure such as the sacroiliac joint or hip
- Repetitive, improper movements or physical activities, such as those commonly found in long-distance running, sitting for lengthy periods of time and/or sports
- Sudden injury, trauma or accident causing irritation to the piriformis muscle or nearby areas, such as the hip or sacroiliac joint
- Previous injuries near the back, pelvis, piriformis muscle or sciatic nerve
- an injury, such as a fall, a blow to the area, or a car accident
- overuse, such as from frequent running, excessive exercise, or over-stretching
- a sedentary lifestyle, especially with long periods of sitting
- changing from a sedentary lifestyle to more frequent exercise
- buttock muscles wasting away
- Tightening of the muscle, in response to injury or spasm
- Swelling of the piriformis muscle, due to injury or spasm
- Bleeding in the area of the piriformis muscle.
- muscle tension and excess weight due to pregnancy
Causes of piriformis syndrome include the following: 
Trauma to the hip or buttock area
Piriformis muscle hypertrophy (often seen in athletes during periods of increased weightlifting requirements or pre-season conditioning)
Sitting for prolonged periods (taxi drivers, office workers, bicycle riders)
Bipartite piriformis muscle
Sciatic nerve course/branching variations with respect to the piriformis muscle
Early (proximal) divisions of the sciatic nerve into its tibial and common peroneal components can predispose patients to piriformis syndrome, with these branches passing through and below the piriformis muscle or above and below the muscle 
In >80% of the population, the sciatic nerve courses deep to and exits inferiorly to the piriformis muscle belly/tendon 
Symptoms of Piriformis Syndrome
- Tenderness, pain, numbness or tingling in the buttocks or along the back of the leg that intensifies without activity
- Pain in the buttock or hip area is the most common symptom.
- Pain may radiate from the buttock area down into the lower leg along the path of the sciatic nerve. Some patients may complain of low back pain.
- There may be numbness and tingling in the buttock area, which can sometimes radiate down to the lower leg.
- Pain with bowel movements may be present.
- Women can sometimes experience painful intercourse.
- There may be tenderness in the buttock area when pressure is applied. Certain patients may have a palpable “sausage-shaped” mass in the buttock area from piriformis muscle contraction/spasm.
- Difficulty participating in daily activities
- Aching, soreness or tightness in the buttocks that can worsen with long periods of sitting, running or walking up or down stairs
- A noticeably reduced range of motion through the hip joint
- Discomfort when light pressure is applied over the p
- Sciatic pain is sharp and searing, rather than dull, and is described as “pins and needles.” You may also experience numbness and weakness in this leg. This pain can be debilitating and make it difficult to stand and walk.
Common complaints associated with piriformis syndrome include
- Pain that becomes more severe following prolonged periods of sitting
- A dull and achy pain located in the gluteus region
- Numbing sensations within the feet
- Pain walking up stairs or an incline
- A headache
- Muscle weakness in the lower limbs
- Difficulty walking
- Reduced range of motion within the hip joint
- Radiating pain
- Abdominal pain, pelvic pain, or groin pain
- Muscle spasms
- Pain during bowel movements
- In women, pain during intercourse