Piriformis Muscle Essentials

The ability to recognize and comprehend the nature of piriformis syndrome requires understanding of the anatomical structure and physiological function of the piriformis muscle and its relationship to the sciatic nerve.

Piriformis Muscle and the Sacrum

The sacrum is a shield-shaped bony structure found between the hip bones and the lower area of the lumbar spine. It is a part of the spine in the gluteal region. The sacrum is connected to the pelvis bones to form the sacroiliac joint. There are two sacroiliac joints in the human body.

Piriformis Muscle

The piriformis muscle is described as a flat, triangular-shaped, and oblique muscle. It begins at the sacrum, between S2 and S4. This opening is considered as the main passageway for the piriformis muscle entering or leaving the pelvis. The piriformis muscle exits through the larger sciatic foramen, occupying most of the passage. After passing through the greater sciatic eminence, the piriformis connects to the upper middle part of the large and bumpy bone on the top side of the hip. The attachment of the piriformis muscle to the greater trochanter is secured by a round tendon. (Boyajian-O’Neill, McClain, Coleman and Thomas, 2008). To be visualize it more clearly, the piriformis muscle runs from the sacrum to the hip joint.
The piriformis muscle is supplied by spinal nerves S1 and S2 and at times, by the spinal nerve L5.
The piriformis muscle acts as an external rotator of the hip, a hip abductor, and hip flexor. During hip extension, the act of bringing the hips backward, the piriformis functions as the main external rotator. In this range of motion, the piriformis muscle assists the thigh in turning outward. During hip flexion, the act of moving the hips forward, the piriformis acts as a hip abductor. Hip abduction is the movement of the leg away from the midline of the body.
Overall, the actions of the piriformis muscle provide postural stability during standing and walking.

Piriformis Muscle and the Sciatic Nerve

The sciatic nerve, similar to most other nerves, performs two essential functions. First, it sends signals to the muscles from the brain, and second, it gathers all the sensory information in the lower extremities and sends it back to the brain. Any abnormal occurrence affecting the sciatic nerve will alter these normal functions. It can be manifested by pain or weakness.

The sciatic nerve is recognized as the largest, widest, and longest nerve in the human body. In an average adult, this nerve has a diameter of approximately 16 to 20 millimeters at its origin near the sacral plexus (Alian and Zhang, 2008). Its diameter is about the size of an adult thumb. It exits the pelvis through the greater sciatic foramen, the same exit point as that of the piriformis muscle. The sciatic nerve then descends between the femur’s greater trochanter and the ischial tuberosity, or the sitting bone. To put simply, the sciatic nerve runs from the lower spine to the buttock and hip area and down the back of each leg.

I hope this gives you a better idea about piriformis syndrome. If you would like to end you piriformis syndrome pain, you should click here.

Rick Kaselj, MS

Overview of Piriformis Syndrome

The term sciatica has been used more frequently in the past few years. This development is probably caused by an increasing number of individuals with spine problems.

Sciatica is described as pain in the low back that shoots down the buttock and the back of the leg. This extremely painful symptom is associated with radiculopathy or compression of the nerve root due to a herniated or prolapsed disc.
Piriformis syndrome can cause pain that is similarly seen in radiculopathy; however, this neuromusculoskeletal condition is due to neuritis, or inflammation of the proximal sciatic nerve, due the piriformis muscle. Piriformis syndrome can disguise itself as other dysfunctions, and as an effect, it frequently goes unrecognized or misdiagnosed.

Piriformis syndrome is also referred to as:

wallet sciatica
pseudosciatica
hip socket neuropathy

Initially described in 1928, piriformis syndrome is a medical problem in which contracture or spasm of the piriformis muscle causes the irritation or compression of the sciatic nerve. This causes of tightening or contracture of the piriformis muscle. I will go into more detail about this later in this report.

Diagnosing and treating piriformis syndrome are difficult at best. In contrast to radiculopathy, people have different anatomical variations with regard to muscle to nerve relationship. In most cases, if signs of sciatica are noted without any clear spinal origin, it is only then that piriformis syndrome is considered as a possible diagnosis.
Similar to true sciatica pain, piriformis syndrome can be a debilitating condition, if misdiagnosed, left untreated or inappropriately managed. It is for this reason that the pain in the buttock, and at times, along the back of the leg and into the foot frequently reported by patients with piriformis syndrome is not always distinguished as true sciatica pain, from a technical standpoint. Health care providers and patients must understand the most essential details of information about piriformis syndrome.

Piriformis syndrome is not a life-threatening condition, but it can significantly cause a decline in one’s quality of life. Often described as a refractory condition, it can be, literally and metaphorically, a real pain in the butt. This ebook will help you understand the essentials of piriformis syndrome, including the anatomy of the piriformis muscle, the causes and their connection to piriformis syndrome development, and the treatment options available, focusing on piriformis syndrome exercises.

What is Piriformis Syndrome?

Piriformis syndrome is mainly manifested by pain in the hip area and buttock. Manifested by a set of signs and symptoms that have a tendency to occur together to reflect a particular medical condition, piriformis syndrome is often missed or misdiagnosed as its overall manifestation is strikingly comparable to that of 5% lumbar radiculopathy (Boyajian-O’Neill, McClain, Coleman and Thomas, 2008). It can also masquerade as sciatica, sacroiliatiis, and intervertebral discitis. Of all these mentioned medical problems, piriformis syndrome is frequently misdiagnosed as lumbar radiculopathy.

Piriformis syndrome involves compression of the sciatic nerve; however, in contrast to other neurolomusculoskeletal conditions, its associated signs and symptoms are caused by a contracted or spastic piriformis muscle. As emphasized, piriformis syndrome is not life-threatening; however, a delay in its diagnosis and treatment cause more severe conditions involving the large sciatic nerve (Brolinson, Kozar and Cibor, 2003). Without implementing the right treatment strategies, compensatory changes may lead to muscle weakness, abnormal increase in sensitivity to stimuli, pain, and paresthesia (Boyajian-O’Neill, McClain, Coleman and Thomas, 2008).

Who will Most Likely get Piriformis Syndrome?

Piriformis syndrome frequently occurs between 40 and 50 years of age, regardless of their past or present occupations and levels of activity.

Women are particularly more vulnerable to develop this condition. Some reports indicated that piriformis syndrome is six times more common in women than in men (Klein, 2010). Its higher prevalence in women is possibly due to the inherent anatomy of the female and the biomechanics involved.

There is a lack of agreement among the experts and clinicians on exactly how to diagnose piriformis syndrome. Accurate determination of its true prevalence continuous to be a great challenge as it is commonly mistaken with other conditions. For these reasons, the frequency of sciatica caused by piriformis syndrome varies widely. Reports by Pace and Nagle, Papadopoulous and Khan, and Foster, it was found that the prevalence of piriformis can be anywhere between 5% and 36% (Boyajian-O’Neill, McClain, Coleman and Thomas, 2008). In a report written by Boyajian-O’Neill et al., it was documented that about 6% of patients diagnosed with chronic low back pain had piriformis syndrome. Given that approximately 90% of adults will have at least one episode of disabling pain in the low back in their lifetime, obtaining an accurate figure has been difficult (Klein, 2010).