Following my February 2007 Massage Today column on sacroiliac joint syndrome, I received several e-mails from therapists asking how to differentiate low back, sacroiliac and piriformis syndrome pain. The first distinction requiring clarification is that piriformis syndrome is considered a “functional entrapment syndrome.” The word “functional” describes neurological compression disorders resulting from positional or kinesiological factors that are not exclusively linked to structural or inflammatory conditions. Therefore, clients presenting with piriformis syndrome for the most part only experience sciatic-like symptoms during certain movements or when pressure is applied to the affected area (Figure 1- reprinted with permission of Medical Multimedia Group).
Sacroiliac and piriformis syndrome anatomy is comprised of many complex elements involving bone, muscle, connective tissue, and nerves. Understanding this anatomy helps reveal the difficulty that exists when developing a healing program for these often-debilitating conditions. Oftentimes, piriformis syndrome pain begins as the external femoral rotator balance that is distorted by pelvic obliquity, due to conditions such as backward sacral torsions, iliosacral inflares and foot hyperpronation. The most common and tormenting of the sciatic-like SI dysfunctions is called a right-on-left backward sacral torsion. It happens when the sacrum gets stuck rotated right and side-bent left between the two innominates. For detailed images, visit my Myoskeletal Alignment articles page.
Normally, backward torsions involve a lifting incident, during which the person bends forward and side-bends left at the lumbosacral junction. Intervertebral discs, facet joints, sacroiliac ligaments, and piriformis muscles are most exposed to injury in this position. However, the movement that precipitates the greatest long-term discomfort takes place when the person attempts to straighten up while L5 is side-bent left and rotated right. As L5 jams backward into the sacrum, sharp, burning sciatic pain shoots into the buttocks and down the leg. Alas, backward torsions commonly are mistaken for disc pathology, causing many unneeded and unsuccessful surgical procedures. Prolonged ligament and joint capsule stress caused by an unstable (crooked) sacroiliac joint can sympathetically spasm the piriformis muscle, causing contracture, fibrosis and sciatic impingement, even though a torsional SI joint fixation may have been the issue responsible for initiating the sciatic assault. Soon, the fibrotic piriformis escalates the symptoms by trapping the nerve between it and other muscles, ligaments or bone in the sciatic notch. The end result of this double-crush disorder is neural breakdown and interruption of the axoplasmatic flow of necessary nutrients. Some researchers estimate that double-crush syndromes occur in as much as 40 percent of the sciatic population.1
Hamstrings and Piriformis Role in SI Dysfunction
Double-crush sciatic pain often originates from a piriformis injury brought on by lifting or overuse. As the L5 facet joints slide forward on the sacrum during trunk flexion, the piriformis and sacrotuberous ligaments must restrain the sacrum from moving forward (counternutation). Unfortunately, tendon, and ligament fibers are vulnerable to microtraumatic tearing during this bending/twisting maneuver. Because the piriformis partially originates from the sacrospinous ligament that is fascially interconnected to the hamstrings, trauma or overuse can create adhesive scar tissue that shortens the piriformis and drags on the sacrum. Exstensive unilateral sacral drag leads to ligament hypermobility, inflammation and sacroiliac imbalance...
Read More ~
Erik Dalton, Ph.D., Certified Advanced Rolfer, started the Freedom From Pain Institute and created Myoskeletal Alignment Techniques to share his passion for massage therapy home study courses, Rolfing, and manipulative osteopathy. Go to the Erik Dalton website for information on workshops, conferences, and CE home study courses.