Client reports, "I have low back pain," as they rub the palm of their hand over their sacrum and ischial tuberosity. They walk with a limp to avoid standing on the painful side (antalgic gait) and are unable to find a comfortable seated position. Hip flexion is limited. Their sacrum and/or coccyx are tender to touch. While each symptom could have numerous origins, let's look at referred pain from myofascial trigger points (TrPs) in the gluteus maximus muscle.

There are numerous ways to differentiate trigger points in the gluteus maximus muscle from trigger points in the gluteus medius, minimus and deep hip rotator muscles, including the location and depth of the trigger points, the referred pain patterns identified and the specific movements that are restricted.

First, a quick anatomy review, proximally the gluteus maximus muscle attaches to the posterior surface of the ilium, posterior surface of the sacrum and coccyx and the sacrotuberous ligament. Distally, the majority of the fibers merge into the iliotibial tract, which is a thickened region of the fascia lata, which attaches on the lateral condyle of the tibia. The remaining fibers attach on the gluteal tuberosity of the femur. (Photo 1) The gluteus maximus muscle is innervated by the superior gluteal nerve (L5-S2).

The main action of the gluteus maximus is extension of the thigh at the hip. It also assists in lateral rotation of the thigh. When standing in forward flexion, the gluteus maximus works with portions of the erector spinae and hamstrings help us to stand erect. Gluteus maximus can influence posture by posteriorly rotating the innominate bone. When you are checking the client's range of motion, if the gluteus maximus is shortened, it will restrict flexion at the hip, verses the gluteus medius and minimus effecting adduction.

Just one or a combination of factors can cause trigger points to develop in the muscle including direct trauma from a fall, muscular stress from poor posture or improper workplace ergonomics. Repetitive movements that include leaning forward, ie: lifting a baby from a crib or lifting boxes off the floor, walking up an incline, hiking up a hill, jumping or running, are possible factors. Sometimes, the cause is a new exercise that requires hyperextension of the hip and low back when standing or prone (ex. swimming the crawl stroke).

Three regions in the gluteus maximus muscle have been identified for locating myofascial trigger points. Each trigger point region produces unique pain patterns. In photo 2, "X" indicates the common location of trigger points and the red color indicates the pain referral areas. Clients will describe the referred sensations from a trigger point as: pain, burning, tingling, numbness, aching, etc.

The region labeled Trigger Point 1 (TrP1) is immediately lateral to the midpoint of the sacroiliac joint. Referred pain from TrP1 can cover the sacroiliac joint, the gluteal cleft and continue over the ischial tuberosity. A small spillover pattern into the upper portion of the posterior thigh is sometimes reported. (Photo 2)

The second region, labeled (TrP 2), is just superior to the ischial tuberosity. Referred pain is often felt over the sacrum (not the coccyx or rectum), over the ischial tuberosity and buttock. The pain may feel like it originates in the deeper muscles. (Photo 2)

The third region (TrP 3) is located in the most medial and inferior fibers and can be the source for coccygodina (pain in or around the coccyx). (Photo 2)

Manual therapy techniques are one link in the healing chain. Teach client's self-care techniques like stretching. Show them how to stretch, when to inhale and exhale, where to place there hands, how to pull their knees to their chest or toward the opposite shoulder, etc.

Client education often involves explaining the negative effects of sitting all day with a wallet in their back pocket. If the client sleeps on their side, suggest they place a pillow between their knees to avoid over stretching the gluteus maximus at night.

Pain over the sacrum, coccyx and ischial tuberosity can start for many reasons. I hope it will be easier to identify and locate these three myofascial trigger points in the gluteus maximus.