Rebecca, a 48-year-old sales associate, stands on her feet all day at work. After driving to Minnesota for Thanksgiving, she developed severe pain in her right buttock, referring down the back of her thigh, and into her calf and ankle. Lying on her right side is painful and prolonged sitting makes it difficult for her to get up from her chair, stand up straight, or walk without a limp. During physical examination, her doctor discovered several trigger points in her right buttock, but no numbness or muscle weakness. An MRI revealed degenerative changes and a bulging disc between the L5-S1. Does Rebecca have “sciatica” or something else?
Sciatica is a term associated with radiating pain from the buttock down to the outer side of the leg, with numbness and weakness usually caused by nerve compression due to severe arthritis in the spine, disc herniation, or spinal stenosis. The gluteal minimus muscle is part of a group of muscles in our buttock, whose primary function is to keep the pelvis level during single-limb weight bearing. Trigger points (TrPs) are muscle “knots” that are tender to the touch and when active, can create pain that radiates into other areas. Active TrPs in the gluteus minimus muscle can be caused by sudden or recurring overload, prolonged immobility, displacement of the sacroiliac joint, and nerve root irritation. Pseudo-sciatica (sciatica-like-distribution) is produced by the TrPs in the gluteal minimus muscle, which can create referred pain from the buttock, down the thigh, calf, leg, and into the ankle. Researchers found that 55 out of 70 percent of patients seen for “sciatica” in fact had ligament or muscle pain caused by gluteal musculature, rather than a pinched nerve. In reality, pseudo-sciatica is more common than sciatica.
During her long drive, her right foot was fixed on the accelerator, which immobilized her right hip muscles and activated TrPs. Furthermore, prolonged sitting and standing can create a weight-bearing overload and shorten the gluteal minimus muscle, keeping the TrPs ablaze. Even though Rebecca’s x-ray revealed degenerative changes in the lumbar-spine with mild disc bulging, her pain is caused by TrPs in the gluteal minimus, thus she has pseudo-sciatica instead of true sciatica. Because x-rays and MRIs can only reveal structural changes, they cannot pinpoint trigger points or muscle pain. Only careful palpitations by your doctor, physical therapist, chiropractor or massage therapist can detect the presence of trigger points.
Treatment of trigger point-induced muscle pain, such as trigger point injection, acupuncture, therapeutic massage, and soft tissue manipulation is quite different from the treatment of arthritis or of a pinched nerve. Jumping the gun and assuming your pain comes from arthritis or a pinched nerve can misguide the treatment plan and prolong recovery.