TO BE A MASTER CLINICIAN, you must become proficient in clinical anatomy, striving to unlock the mysteries of anatomy, optimum human function and sources of dysfunction. Over the years, I have learned that there are certain anatomical crossroads that lend themselves to patterns of dysfunction and injury. Most of us are familiar with some of these anatomic junctions where dysfunctions are common: the carpal tunnel, the piriformis, the thoracic outlet, the iliotibial band, the inguinal ligament, the sacroiliac joint, the plantar fascia, and of course, the spine. Here, I present another clinically significant anatomical juncture, the sacrotuberous ligament, the pudendal nerve and the sacrospinous ligament. [This is part four of a four-part series. See “Nerve Entrapment (Part One): Lumbo-Pelvic Pain,” Oct. 2015 ACA News, Page 26. See “Lumbo-Pelvic Pain (Part Two): Cluneal Nerve Entrapment,” Nov. 2015 ACA News, Page 22. See “Skinny Jeans Syndrome, Lumbo-Pelvic Pain (Part Three): Meralgia Paresthetica,” Jan./Feb. 2016 ACA News, Page 22.]
I was first introduced to the clinical significance of the sacrotuberous ligament and the sacrospinous ligament by my instructor Patrick Montgomery, DC, at Palmer-West. Dr. Montgomery was a favorite instructor for most students at Palmer. This was due to his very practical clinical knowledge in chiropractic technique; he taught Logan Basic Technique.
Logan University Founder Hugh Logan, DC, heavily emphasized the treatment of this ligament for patients with spine conditions, not simply for low-back pain. He believed a very light and precisely vectored contact on the sacrotuberous ligament would normalize the sacral position and, through that effect, the entire spinal column; in fact, he believed that other subluxations of the spine would be self-correcting if only the primary sacral subluxation was corrected. While I acknowledge the intent of Dr. Logan’s technique for correcting subluxations, this article concentrates on using his technique to treat pudendal neuralgia.
Sacrotuberous Ligament: Anatomical Significance
The sacrotuberous ligament arises from the posterior sacrum and the upper coccyx, with its fibers blending into the complex network of the posterior ligaments of the sacrum, connecting this ligament to the posterior superior iliac spine. It extends to the ischial tuberosity. The sacrotuberous ligament contributes to the strength of the pelvis, inhibits nutation and provides an attachment point for muscles (e.g., gluteus maximus and the long head of the biceps femoris). Some fibers of the long head of the biceps femoris attach to the sacrotuberous ligament (sometimes absent in anatomical variants), and the inferior fibers of the gluteus maximus attach to it as well. Some authors have credited the biceps femoris with providing an active component to sacroiliac stabilization. While far from providing conclusive evidence, some clinical studies have linked normal hamstring function to the enhancement of sacroiliac stability. Additionally, sacroiliac dysfunction has been associated with gluteus maximus weakness. The sacrotuberous ligament is clearly a significant component in joining the myofascial trains of the lower extremities to the upper body.
Another ligament in this region, the sacrospinous ligament, is deep to the sacrotuberous ligament. It arises from the lateral sacrum and coccyx and attaches to the spine of the ischium (see Figure 1). Of clinical significance is that the pudendal nerve travels between these two ligaments and can become entrapped.
Pudendal Nerve Entrapment
Pudendal nerve entrapment between the sacrotuberous and sacrospinous ligaments can result in pudendal nerve neuralgia. Pudendal nerve entrapment can result in recurrent pain or numbness of the genitals, rectal pain, reduced awareness of an impending bowel movement, disturbance of normal urination (including overactive bladder), altered sensation during ejaculation and urinary or bowel incontinence.
Pudendal nerve entrapment can be profoundly life-changing, but due to the intimate nature of the symptomatology, many people suffer in silence. Medical treatment for pudendal neuralgia includes pain injections, surgical decompression and drugs. Chiropractic options include adjustments, pelvic floor myofascial treatment, modalities (such as cold lasers) and my preferred method, the Logan Basic Technique.
Sacrotuberous Ligament: Manual Treatment
While I cannot adequately describe here all of the specifics, principles and techniques that comprise Logan Basic Technique, I will share the basic concept of the contact and my adaptation of this technique. For a more detailed instruction, I recommend a technique class on the subject.
The patient is positioned in a prone position, flexed slightly at the waist and at the knees with any outer, restrictive clothing removed. The doctor of chiropractic (DC) is contralateral to the side being treated. The DC palpates to locate the coccyx and then palpates out lateral from the coccyx to find a web-like structure, which will feel similar to the web between your fingers. This web is the sacrotuberous ligament. The DC will then hook the tip of the thumb under the anterior portion of the ligament and distract posteriorly, slightly oblique and superior. The pressure is light but constant. The direction of pressure can be altered gradually and slightly. While maintaining the contact, the basic technique has you palpate the paraspinal muscles for feedback to determine when to change the contact or discontinue. I usually perform the contact for 45 to 60 seconds.
While I am the first person to admit that the success of this technique is based almost exclusively on clinical outcomes and that there should be more research to validate its success in treating pudendal neuralgia, I am also the first to tout the numbers of referrals from medical providers at our hospital for treatment of this malady with this technique.
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3) van Wingerden JP, Vleeming A, Buyruk HM, Raissadat K. Stabilization of the sacroiliac joint in vivo: verification of muscular contribution to force closure of the pelvis. Eur Spine J. 2004;13:199–205.
4) van Wingerden JP, Vleeming A, Kleinrensink GJ, Stoeckart R. The role of the hamstrings in pelvic and spinal function. Vleeming A, Mooney V, Snijders CJ, Dorman TA, Stoeckart R. Movement, stability and low back pain: the essential role of the pelvis. 1997. New York: Churchill Livingstone; 207–10.
5) Loukas M, Robert G Louis Jr RG, Barry Hallner B, Gupta AA, White D. (2006) Anatomical and surgical considerations of the sacrotuberous ligament and its relevance in pudendal nerve entrapment syndrome. Surg Radiol Anat. 28(2): 163-169.
6) Cooperstein R, Lisi A, Burd A. Chiropractic management of pubic symphysis shear dysfunction in a patient with overactive bladder. J Chiropr Med. 2014 Jun; 13(2): 81–89.
Dr. Morgan divides his clinical time between a hospital-based chiropractic clinic and executive health clinics in Washington, D.C. He is adjunct faculty for a medical school and several chiropractic colleges. He is on the board of trustees for Palmer College of Chiropractic. His speaking calendar can be viewed at http://bethesdaspineinstitute.com. He can be reached through his website, www.drmorgan.info.