The sacrotuberous ligaments form a crucial structural crossroads in the human body. As mediators between the spine and legs, this pair of strong, broad ligaments bridges the upper and lower body; as stabilizers of the sacrum, they accommodate the left/right forces of foot-to-foot weight transfer; in efficient walking and running, these ligaments are key connective-tissue links in the chain of kinetic energy uptake, adding spring to each step.1
That is, they do these things when they’re balanced and healthy. When they aren’t, the sacrotuberous ligaments can play an equally significant role in many client complaints, including low-back pain,2 a condition that affects nearly 95 percent of all Americans at some point in their lives. While the sacrotuberous ligaments aren’t involved in all back pain, a very large portion of low-back pain cases stem from issues related to these important ligaments, including:
• Sacroiliac joint hypermobility, hypomobility, and pain. When one sacrotuberous ligament is tighter than the other, it can be associated with sacral rotation, side bending, or fixation.
• Coccyx (tailbone) injuries and pain, since the sacrotuberous ligament attaches to and stabilizes the coccyx.
• Sciatic pain (both axial and appendicular), including piriformis syndrome, since the sciatic nerve and piriformis are close neighbors.
• Peroneal pain and numbness, as the pudendal or cutaneous nerves can become entrapped within the sacrotuberous ligament, or between it and the sacrospinous ligaments.
• Painful sitting, hamstring tendinitis, or ischial bursitis.
• Leg length differences, both anatomical and functional.
• Spinal scoliosis or lordosis (swayback).
• Pelvic torsions, upslip, and pubic symphysis irritation.
• Slumped or twisted posture in sitting or standing, since the sacrotuberous ligaments are key determinants of sacral angle and segmental relationships all the way through the body.
• Pelvic floor, prostate, and urogenital issues, because muscles and fascia of these structures attach to the sacrotuberous ligaments.
In addition, many models of movement and fascial continuity describe the sacrotuberous ligament as a key structure. At its superior origin at the posterior superior iliac spine (Image 2), its fibers are continuous with the back’s lumbar intermuscular aponeurosis.3 Inferiorly, its superficial fibers cross the ischial tuberosity in about 50 percent of people, and are thus continuous with the biceps femoris tendon in the leg.4 Each of these structures continues, in turn, as parts of longer chains. These long connections through the body lend the sacrotuberous ligament (in its central location) its linchpin role in whole-body theories of connective-tissue relationships, such as Thomas Myers’ Anatomy Trains model, the ipsilateral longitudinal sling concept in functional medicine, or Serge Gracovetsky’s Spinal Engine theory.
Functionally, the bilaterally oblique arrangement of the two sacrotuberous ligaments serves to prevent the sacrum from being tipped forward (into anterior nutation) by the downward pressure of the spine. Together with the sacroiliac and sacrospinous ligaments, the sacrotuberous ligaments also stabilize the sacrum against excessive side bending and twisting within the pelvis. Because of this paired, left/right arrangement, a side-to-side imbalance in the sacrotuberous ligaments’ length or tension will be linked to sacral rotation, pelvic torsion, and strain on the sacroiliac joints and low back.
Sorting out the root cause of sacrotuberous ligament imbalances can be a chicken-or-egg pursuit: are the ligaments different left and right because of a pelvic torsion, or is their difference causing the pelvic asymmetry? Often, determining cause can be elusive. On the other hand, an injury or an observable structural irregularity (such as an anatomical leg-length difference) can make the root cause of imbalance clearer. The sacrotuberous ligament can be strained or injured in sports and activities that involve arching or twisting the low back, such as basketball, golf, gymnastics, hurdles or jumping, pitching, tennis, or volleyball spiking. Falls onto the buttocks or other direct trauma can strain or tear the sacrotuberous ligament, as well as injure the coccyx. Lifting or bending injuries, repetitive and asymmetrical activities, hamstring tendinitis, and pregnancy can all cause strain and sensitivity as well. The result of any of these impairments is often inflammation, scarring, adhesions, pain, and loss of connective-tissue adaptability.
Sacral Balance
Even when the cause or source of a left/right sacrotuberous ligament imbalance is not apparent, your work here can nevertheless be helpful in addressing the related conditions listed above.
The boney space between the sacrum and the ischial tuberosity is often palpably different left to right, with one side often being more open or wider than the other; this indicates an asymmetrical pelvic pattern, most likely involving sacral side bend or rotation. Sacral biomechanics are complex and quite arcane, and their details are beyond the scope of this article. However, one useful principle is that if the space between two bones (the sacrum and the ischial tuberosity, in this example) is shorter on one side of the body, the ligament on the shorter side will be tighter or harder if it is a contributor to the asymmetry, but softer if it is being slackened by the boney asymmetry (that is, if the asymmetry is due to other forces or structures and not the ligament itself). Furthermore, if a ligament is tighter on the longer or wider side, it is most likely being stretched by the structural asymmetry, and the root cause lies elsewhere (for example, leg length, patterns of usage, etc.).
Using these principles, you would then work more with the tighter or harder sacrotuberous ligament if it was on the side of the sacrum with less space between it and the ischial tuberosity (the shorter or narrower side), but work elsewhere in the body (such as the hamstrings or hip joint) when the tighter sacrotuberous ligament is on the longer side.
If you suspect sacrotuberous ligament involvement in your client’s symptoms, but don’t perceive a length or tissue difference left and right, let your client’s experience be your guide: work one side, and then have your client get up and walk or bend. Easier than before? You’re on track. Not easier? Work the other side’s sacrotuberous ligament, and recheck. Clients will frequently report less pain and greater ease when you work in this way to balance any left/right differences you find in the sacrotuberous ligaments.
Sacrotuberous Ligament Technique
Because the sacrotuberous ligaments are in a personal, private part of the body, before working with them it is important to get your client’s explicit consent and buy-in. Inform your client of the reasons for working the ligaments. I’ll often show my clients the anatomy involved,5 and I always explain why I think work here might be helpful by relating it to their particular symptoms. If you haven’t already been trained in sacrotuberous ligament work, get familiar with the anatomy of the area by practicing palpation with a colleague or learning partner before attempting these techniques on a client.
Once you have your client’s permission to work these ligaments, stand at his or her side, and begin by making tactile contact somewhere other than the ligament itself (such as the knee or low back). In other words, ease into the area being worked. Checking in with your client all the while, reach across the body to find the opposite-side ischial tuberosity with one hand, and the posterior side of the coccyx with the other. The sacrotuberous ligament runs between these two landmarks, just anterior to the medial margin of the gluteus maximus. Palpate the sacrotuberous ligament on the lateral side of the upper gluteal cleft. Work on the opposite side of where you’re standing, as this gives a better angle for your two thumbs to gently but firmly press into the ligament’s inferomedial margin (Image 5). You aren’t trying to feel the ligament through the gluteus; rather, you’re feeling in front of the gluteus maximus. The ligament will feel ropy or hard on most people; remember, it is in front of the gluteal mound.
Keep your two thumbs together in order to avoid straining them. Switch sides of the table and use this stable mono-thumb to compare the hardness and tension of the left and right ligaments. Also, compare the boney space and tissue quality on each side of the coccyx. The sacrotuberous ligaments and sacrospinous ligaments converge here, and each can contribute to coccyx pain or misalignment.
Once you’ve assessed both sides, spend comparatively more time on the side where you found the harder ligament or less boney space. Beginning with the upper or proximal end of the ligament, find a level of pressure that your client can relax into, and wait for a sense of tissue release in each place before moving slightly to the next part of the ligament. Avoid sliding or friction—static, focused, firm but receptive touch will allow your client to release the tissues in a way that won’t be possible if your touch is active or moving.
Around the coccyx itself, work patiently to gradually release the ligaments and tissues surrounding the tailbone using sensitive, stationary thumb pressure. Again, spend more time on the shorter, harder, or narrower side of the coccyx. Rather than attempting to straighten any boney crookedness you find in the coccyx, your goal is evenness of tissue tone on each side of the tailbone, along with gentle desensitization of any painful or excessively guarded areas. If the coccyx has been injured, for example in a fall or in childbirth, it can be extremely sensitive. If you work slowly enough that your client can continue to relax and breathe freely, you’ll see any hypersensitivity diminish.
After working the upper end of the sacrotuberous ligament, continue working down the length of each ligament, one area at a time. If there is peroneal pain or numbness, pay special attention to the midsection of the sacrotuberous ligament, since it is here that the pudendal nerve can be entrapped between the sacrotuberous ligament and the deeper sacrospinous ligament. Continue your step-by-step release until you reach the ischial tuberosity. Alternatively, you can add passive or active leg rotation to access different aspects of the ligament (Image 6). Another alternative is to work the sacrotuberous ligament with your client in a side-lying position, carefully using the elbow to address the ligament on the lower side of the body.
Finish your sacrotuberous ligament work on each side with special attention to the medial aspects of the tuberosities and ischial ramus, where pudendal nerve impingements can also occur in the area of the ligament’s falciform process (Image 1).6
Summary
Done sensitively and properly, this work will feel deep and very effective, rather than invasive or overly personal. Including the sacrotuberous ligaments in your work will help you more effectively address a wide variety of structural and functional conditions, reflecting the critical role these structures play in efficient posture and function.
Til Luchau is a member of the Advanced-Trainings.com faculty, which offers distance learning and in-person seminars throughout the United States and abroad. He is also a Certified Advanced Rolfer and has taught for the Rolf Institute of Structural Integration for 22 years. Contact him via info@advanced-trainings.com and Advanced-Trainings.com’s Facebook page.
Notes
1. S. Gracovetsky, The Spinal Engine (New York: Springer-Verlag, 1988).
2. J.P. van Wingerden et al., “The Spine-Pelvis-Leg Mechanism; with a Study of the Sacrotuberous Ligament,” First Interdisciplinary World Congress on Low Back Pain and its Relation to the Sacroiliac Joint (San Diego: Rotterdam ECO, 1992): 147–8.
3. Warren Hammer, Functional Soft-Tissue Examination and Treatment by Manual Methods (Connecticut: Jones & Bartlett Learning, 2007): 438.
4. A. Vleeming et al., “The Sacrotuberous Ligament: A Conceptual Approach to its Dynamic Role in Stabilizing the Sacroiliac Joint,” Clinical Biomechanics 4, no. 4 (1989): 200–3.
5. It would be ungracious not to mention Primal Pictures here, to whom I owe much thanks for the use of their outstanding anatomical imagery, which I use with my clients, in our trainings at Advanced-Trainings.com, and in this column.
6. The falciform process of the sacrotuberous ligament, present on about five people in six, blends with the fascial sheath of the internal pudendal vessels and nerves.