Post by Anna Walsh, Physiotherapist
The piriformis is an important muscle in the gluteal or buttock region. It sits deep to the gluteus maximus, which is the muscle which gives shape to your backside. The piriformis muscle runs from the side of the sacrum (tailbone), outward and across to the greater trochanter (outside of the hip or femur). Underneath the piriformis muscle lies the sciatic nerve, which passes down the back of the thigh and branches off into the lower leg. In 15% of the population, the sciatic nerve actually pierces through the piriformis, putting these people at a somewhat higher risk of developing Piriformis Syndrome.
This condition refers to compression or irritation of the sciatic nerve by a shortened or spasming piriformis muscle, usually due to trauma or overuse. Symptoms include pain, tingling or numbness in the buttocks and down the back of the thigh or lower leg. Another smaller nerve, the pudendal nerve, may or may not also be involved. In cases of pudendal nerve entrapment, symptoms to look out for include bladder and bowel dysfunction or groin/saddle region tingling or numbness. The sciatic nerve can commonly be irritated by a bulging lumbar disc, so lower back pathology should be ruled out by your Physiotherapist when diagnosing Piriformis Syndrome.
Potential causes of this condition include unwanted inactivity of the gluteals or buttocks as a whole. This may be due to shortening of the hip flexors at the front of the hip. The hip flexors may become tighter with overtraining in running drills, and may be worsened by following this with long periods of sitting, such as office work. The inactive larger gluteal muscles are compensated for by other muscles, including hamstrings and the piriformis itself, which may then become overused and place pressure on the nerve.
Overuse of the piriformis muscle is common in runners, rowers and cyclists. Disproportionately weak hip abductors (larger buttock muscles and outside hip muscles) and tight adductors (inner thigh muscles) can be a negative effect of too much forward motion training, as is often the case with such athletes. Hip abductor strengthening exercises should follow a graduated progression from non-weight bearing (sidelying) to weight-bearing (standing using body weight) to functional (explosive, propulsive drills). Adductor stretching is equally important.
Your Physiotherapist, Exercise Physiologist or Strength and Conditioning Coach can direct you towards the best way to manage this condition, and should progress you through a series of strengthening and stretching exercises as your symptoms allow. Remember, Piriformis Syndrome can be quite restricting, limiting your ability to run, walk and even sit down. Most commonly aggravated by sitting on hard surfaces, relief can be gained by sitting on a cushion or better still an inflatable “donut” pillow. Avoid placing a wallet in the back pocket of trousers when sitting. Rest from running is definitely advised, and cross training should be done to keep up cardiovascular fitness. Deep water running and swimming are particularly effective as they are free of impact. Pilates and yoga are useful to maintain core stability and flexibility, and when performed correctly may in turn lead to more efficient training and running technique once symptoms subside.