Erik Dalton - Piriformis or SI Joint Pain?

Piriformis or SI Joint Pain?
by Erik Dalton Ph.D., Certified Advanced Rolfer®
founder of Freedom From Pain Institute™

A frequently asked question in Myoskeletal Alignment® seminars is how to differentiate sacroiliac from piriformis syndrome pain (Fig. 1). Indeed, these structures are often involved in a symbiotic relationship. Length/strength piriformis imbalance strongly influences movement of the sacrum between the two hip bones and clinically, we know both can cause sciatic-like symptoms – a condition which affects nearly 40 percent of adults at some point during their lifetime.1 But, unlike SI joint dysfunction, piriformis pain is a “functional entrapment syndrome” resulting from a positional abnormality in which the sciatic nerve becomes compressed between piriformis and either the sacrospinous ligament and/or, the bony sciatic notch. The burning question is... why are some clients symptomatic and others not? Is there a genetic predisposition or could a torsioned pelvic bowl possibly be contributing to this painful dysfunction? In my early Rolfing days, I blamed piriformis syndrome on almost all non-low back sciatic pain symptoms because it was so easy to visualize muscle pushing on nerve. But through dissection studies, it became clear that even in athletic overuse cases, it takes more than a vigorous rubbing to damage the sciatic's enveloping dura mater (Greek for tough mother). Much like lumbar intervertebral disc herniations, the sciatic nerve must be squashed against something to trigger intraneural edema and accompanying neurological symptoms such as pain, numbness, tingling and weakness.

It is estimated that 40% of non-discogenic sciatica results from SI dysfunction and piriformis syndrome. 2 Of the six groups of hip and thigh muscles attaching to the pelvis, the piriformis suffers the greatest stress when it comes to binding down (stabilizing) the SI joint. Therefore, a torsioned pelvis due to foot pronation, a valgus knee, etc. can drag piriformis into an altered position in the sciatic notch causing sciatic nerve entrapment between muscle and bone (Fig. 2) Bilateral hip and leg pain may indicate a 'double-crush' syndrome where lower quadrant muscle asymmetry displaces one SI joint and entraps the sciatic under piriformis on the contralateral side (Fig. 3).

Bottom Line: Even in the presence of a positive Pace, Freiberg or Beatty test, piriformis syndrome should never be treated as an isolated event. A successful therapeutic approach begins with a full spinal and pelvic evaluation including functional spring tests, muscle length/strength comparisons, hip abduction firing order exams and, in extreme cases, an orthopedic referral may be necessary. I've found the new MRI neurography scan to be very helpful in weeding-out questionable piriformis, thoracic outlet and carpal tunnel syndrome cases. Once positive identification of sciatic entrapment between the piriformis and bone (or sacrospinous ligament) has been verified, hip external rotator releases such as those shown in Figures 4 and 5, should help relieve neural compression allowing the dural membrane and capillary beds to heal.

For the rest of this article go to: http://erikdalton.com/piriformis-or-si-joint-pain/