Piriformis syndrome is one of the possible causes of sciatica in pregnancy. The piriformis muscle lies deep within the pelvis. The sciatic nerve passes either over, under or within this muscle. If the piriformis is tight is can compress the sciatic nerve causing the radicular pain. The diagnosis of this condition is generally one of elimination when all other potential causes have been ruled out. This condition does not show up on common imaging techniques of X-ray, CT scan or MRI.
What's happening in piriformis syndrome?
Weakness and/ or inactivation of the gluteus medius causing the piriformis muscle to be overworked, tight and easily fatigued.
- Inactivation of the piriformis muscle caused by reciprocal inhibition from overactive hip flexor muscles. This can occur due to prolonged sitting (ie- office workers).
- Overuse can cause the piriformis muscle to hypertrophy or grow in size. Like any other muscle in the body (eg-biceps), if you increase the load, it gets larger. If the muscle gets too large, it starts to compress the sciatic nerve and cause symptoms of sciatica.
- Overuse of the piriformis such as with cycling, rowing or excess driving.
- Overuse of the piriformis associated with a waddling gait or excess rotation your legs outwards to increase stability in the later stages of pregnancy.
- Dysfunction in the joints of the pelvis altering gait and biomechanics of the lower limb resulting in increased strain on the muscles.
- Over pronation (flattening ) of the foot results in medial rotation of the knee which activates the piriformis muscle to reduce further rotation. Overtime this can cause hypertrophy of the muscle.
Specific symptoms of piriformis syndrome
- Symptoms can be worse after physical activity in which the piriformis and gluteal muscles are fatigued. Eg- long walks, standing for long periods, long drives.
- You may find your symptoms are aggravated in positions where you stretch the muscle such as putting socks and shoes on, sitting crossed legged, resting your foot on your opposite knee.
- Muscular pain localised deep in the pelvis, behind the hip.
Generalised symptoms of sciatica
The primary symptoms are all neurological or nerve based due to the compression on the sciatic nerve or nerve roots, one or more of these symptoms need to be present in order for the diagnosis to be sciatica.
- Pain that starts in the low back or buttock, and radiates down the thigh and typically into the lower leg and/or the foot.
- The pain experienced tends to be a sharp pain, as opposed to a throbbing or dull ache. Words people often use to describe sciatic nerve pain include burning, searing, sharp pain.
- In addition to pain, other common symptoms include heaviness, tingling, pins and needles, numbness and weakness in the thigh, leg or foot.
- Pain levels can range from dull to extreme.
- Decrease in reflexes may be picked up by your Doctor or therapist.
- Symptoms typically only occur in one leg.
- Difficulty is walking due to foot drop caused by neurologic weakness.
- In extreme cases loss/change in bladder and bowel control.
- Acute muscle spasms/cramps.
Please ensure that you speak to your GP, Obstetrician, midwife or other therapist if you are experiencing any of these symptoms.
Treatment of piriformis syndrome
- Stretch the piriformis muscle.
- Stretch the hip adductors and flexors.
- Decrease sitting time if possible.
- Increase variety in your exercise regime to include such things as swimming, yoga, pilates and walking. Decrease cycling and running.
- Strengthen your glute medius muscle.
- Get your feet checked for over pronation.
- Lying with tennis balls under your pelvis can help reduce muscle tension.
Please refer to the post on sciatica for other generalised suggestions for management of sciatica in pregnancy.