First described in 1928, piriformis (peer-ee-form-us) syndrome is a painful neuromuscular disorder that occurs when the piriformis muscle irritates and/or compresses the proximal sciatic nerve. Sometimes referred to as wallet syndrome, pseudosciatica, or hip socket neuropathy, piriformis syndrome is six times more prevalent in females than males. This may be caused by differences in the angle of the quadriceps femoris muscle, differences in pelvic structure, or to hormonal changes, especially during pregnancy, that affect the muscles around the pelvis.
The piriformis muscle is a flat pyramid-shaped muscle located deep in the buttocks near the hip joint that connects the sacrum to the top of the femur. Activation of the piriformis muscle lifts and rotates the thigh away from the midline of the body, allowing us to walk by shifting weight from one foot to the other and to maintain balance. The muscle is activated during all movements that require lifting and rotating the thighs — the vast majority of hip and leg motion.
Passing alongside, or in some individuals through the piriformis muscle, the sciatic nerve descends down the back of the thigh to the lower leg and eventually branches into smaller nerves that terminate in the feet. Although relatively rare, piriformis muscle spasm also can impinge the pudendal nerve that controls our bowels and bladder, resulting in groin tingling, numbness, and sometimes even incontinence.
CAUSES AND SYMPTOMS OF PIRIFORMIS SYNDROME
Compression or irritation of the sciatic nerve can occur when the piriformis muscle becomes inflamed, has spasms, or becomes tight. Typically, this results from overuse, prolonged sitting, and activities such as rowing in the sitting position. In addition, weak hip abductor muscles, such as the gluteals, combined with tight adductors, increase the risk if they do not engage regularly. Athletes performing forward-moving activities such as running and cycling are more susceptible to the disorder, especially if they do not engage regularly in lateral stretching and strengthening exercises. Excessive or prolonged sitting (e.g., the hips flexed while sitting at work) also increases the likelihood of developing piriformis syndrome.
Piriformis syndrome is not diagnosed frequently because the symptoms of the disorder mimic those of sciatica and a definitive diagnostic test is lacking. Typical symptoms can include:
- Tenderness or pain behind the hip, in the buttocks
- Pain can radiate down the back of the leg into the hamstring muscles and, at times, the calf muscles.
- Numbness and tingling in the lower extremity
- Tenderness when pressure is applied on the piriformis muscle, such as with sitting
- Low-back tenderness and pain
Conservative treatment includes nonsteroidal anti-inflammatory medications for symptom relief, massage, pain-free stretching exercises, and avoidance of contributing activities such as running, cycling, and rowing. Avoidance of prolonged sitting is highly recommended, and short movement breaks every 30 minutes also are recommended. Light stretching is recommended three to four times per day up to, but not beyond, the point of pain.
As symptoms alleviate, strengthening exercises should be added that involve the hip abductors, adductors, external rotator, and extensor muscles. A physical therapist or personal trainer can provide guidance with developing an appropriate strengthening and stretching routine.
Most causes of piriformis syndrome are preventable and frequently are related to activities of daily living. Avoidance of prolonged sitting and utilization of correct sitting posture are two important prevention strategies and essential for other aspects of overall health and wellness. Other preventive strategies include:
- Using a proper warm-up and cool-down period
- Maintaining correct posture with even weight distribution on both feet
- Wearing proper-fitting shoes that are not worn out
- Using correct lifting techniques
- Regular stretching
- Strengthening exercises that include activities such as:
- ○ Resistance band abduction and adduction exercises
- ○ Side-lying clam shells
- ○ Stability ball wall squats
Although a painful and restricting condition, piriformis syndrome largely is preventable. Avoidance of prolonged sitting and chronic repetitive activities, along with undertaking proper warm-up, stretching, and strengthening exercises, will minimize the risk of developing this debilitating condition.