Is This You or Someone You Know?
Read on to understand the dire effects this hypermobility might have on the sacroiliac joints and other body tissues and organs.
This physical act is usually referred to as “being double-jointed” in people talk, but, in reality it is being “hypermobile”. This mobility in some can go so far as to cause the joint to slip out of its socket temporarily with a clunking sound. Most everyone knows someone who can “dislocate” a shoulder or a hip whenever they want, and then put it back in place, all without much effort. It is frequently done to show off as a performance to get attention. Although these hypermobility stunts can be amusing, there are real physiologic reasons for their presence and real potential consequences for those showing off this very common skill.
The science behind it lies in our connective tissues and how they are created and metabolized in each individual. Connective tissues are what holds us together. They are what forms our ligaments and the joint capsules that hold each of the joints in our bodies together. Without ligaments and joint capsules, we would all be just a pile of bones and muscles and totally functionless. No two bones in our bodies would be able to maintain an attachment to each other that a muscle could span them and provide movement between the two. When we have strong ligaments and thick firm joint capsules, we are capable of being stable and strong as we go about doing the activities our functional daily living demands. Strong joints and exercise allow us to become even stronger by giving the muscles leverage as they expand or contract.
Connective tissue is made up of collagen of which there are several types in humans. So far 28 types of human collagen have been identified and described, but Type I collagen is responsible for 90% of all the collagen in our bodies. This is the human tissue that makes up our skin, ligaments, joint capsules, blood vessels, organs, bone and more. When a person has normal type I collagen all is well for their joint stability, but when abnormal Type I collagen exists it can result in anything from the nearly imperceptible, except for the noticeable hypermobility or “double jointed”, to severely deforming and life-threatening hazards. The two most severe abnormalities result in osteogenesis imperfecta and Ehlers Danlos Syndrome. Although there are multiple expressions of these two disorders in humans, they are fortunately not common. For the purposes of this article I will concentrate on the mild form as depicted in the photograph above. Most of these individuals, especially women, having this hypermobile joint have no idea they even have it and that in hundreds of thousands of people it is only a benign reflection of potentially more serious problems within them.
The loose finger photograph is one that I published as part of an article in a medical journal in 1992(1). I was detailing the results of a scientific study comparing the frequency of low bone density in people with a hypermobile finger joint. There was a 90% correlation of lower than normal bone density in consecutive Caucasian women having this hypermobility. It was with this study that I began a career of learning more about how loose connective tissue affects, not only the musculoskeletal system, but many other vital tissues in our bodies. I began communicating with some of the most brilliant researching minds in our country at that time who were studying human connective tissue and the consequences possible when it wasn’t normal or there was less of it. For our purposes here two major lessons emerged. One was that there are millions of people, more women than men, having connective tissue which allows the type of hypermobility seen in the above photo. The other is that the majority of these are Caucasian women of northern European decent having fair skin, light hair and light eyes. In most of these individuals their connective tissue is entirely normal in its molecular structure, but the problem is that there is much less of it. The way this was explained to me by these experts; bear in mind I am not an expert on this, and I am simplifying it enormously; is that, through the transference of an abnormal gene in DNA an “inborn error in collagen metabolism” occurs. The subsequent collagen fibrils that are manufactured are both normal and abnormal. The abnormal ones are metabolized out leaving the normal ones intact. This gives the person normal collagen only much less of it. As a result of having less-than-normal collagen fibers, their joint capsules are not as strong and hypermobility of a joint results. Most of the millions of people in which this occurs see themselves as, and act, as though they are entirely normal.
So how does all this affect the sacroiliac joint. When I published this scientific paper on hypermobility, I really knew nothing about its relationship to this joint. The year before I had operated on my first sacroiliac joint patient with rheumatoid arthritis and was in the process of publishing that case. As a result, I was following both hypermobility and chronic sacroiliac joint pain intensively without yet realizing there was a relationship between them. As with most of my education on these two subjects, my patients’ experiences were the most valuable source of information. It was through the Caucasian women that were hypermobile, had fair skin and light eyes, and largely from northern European descent, who had chronic sacroiliac joint pain lasting years after vaginally delivering their first child, that I started to associate hypermobility with the sacroiliac joint. It was in these individuals that conservative treatments for their ongoing low back pain weren’t working, and only finally achieved significant or total relief from fusion of their sacroiliac joint.
It is well known that the very ligaments and joint capsules that hold the sacroiliac joints together to promote pelvic stability are drastically affected by the hormone Relaxin in pregnancy. During the later stages of pregnancy and especially delivery this hormone allows these supporting structures to soften and become more elastic to allow the pelvis to spread for the baby’s head. This in itself can cause significant pain. During the post-partum phase all returns to normal. This is unless the ligaments or joint capsules were stretched too far and injured. This was the situation in countless patients of mine that were hypermobile to begin with.
Read Laura’s true story in my recently published book for the
lay person on the subject of chronic sacroiliac joint pain, which
can found on Amazon titled, “Sacroiliac Joint Pain: For Tens of
Thousands the Pain Ends Here”(2).
The reality for these women was that, although they had normal type I collagen, they had too little of it in their ligaments and joint capsules to meet the needs of a vaginal delivery without getting injured. Thanks to modern awareness this type of injury to sacroiliac joints in women is more understood. What is not fully understood is that a hypermobile finger joint, fair skin, light eyes, and northern European decent can be important easily seen clues in patients with chronic low back pain caused by sacroiliac joints. In terms of trying to rehabilitate these individuals, it is a lot like trying to treat the chronically unstable sprained ankle.
As I continued my observation of hypermobility and the painful sacroiliac joint, I began to realize that hypermobile people who never delivered a child vaginally, especially Caucasian women of northern European decent, were at greater risk for both chronic sacroiliac joint pain as well as failing all appropriate methods to conservatively attempt to cure it. I also began to frequently observe other physical findings as well that became important to follow as part of their overall care. I began ordering bone density tests on these patients and found the majority fell in the osteopenic range (less than normal bone density but not quite full osteoporosis), reflecting they had less Type I collagen than normal. It was also interesting that many of them had a history of a previous long bone fracture with several of those occurring in childhood. Many had a central bulging lumbar disc on their MRIs with some being very impressive in size. The long central ligament that spans the posterior central portion of the vertebra and discs from the base of the skull to the sacrum and is responsible to prevent this has the same laxity under enormous stresses as all their other hypermobile tissue. This finding of course helped to confound the true diagnosis of where the low back pain was coming from in these individuals. Mild amounts of scoliosis, some over 20 degrees were identified in many of these same patients. Since most of these had no significant progression I always felt that these curves were simply a reflection of each spinal segments hypermobility effect on the one above or below it. The resulting curve was simply the position of most stability for the patient. If you did side bending X-Rays on these curves they were very mobile. Since this form of scoliosis is not listed in the differential diagnosis for this condition, I’ve always wondered how many of these kids were put in braces by spine surgeons through the years.
Some of the more severe relationships with hypermobility can occur with the internal organs. The blood vessels contain Type I collagen and in the arterial system can be under much physical hydraulic pressure. If there it hypermobility in these tissues it can result in aneurysms, which is a ballooning of the vessels that can go on to possibly rupture (e.g. brain aneurysm, aortic aneurysm). Abnormal Type I connective tissue has been thought to possibly be implicated in various other conditions ranging from the cysts in polycystic kidneys to the diverticula in diverticulitis of the colon. The bottom line here is that science has barely scratch the surface on how hypermobile connective tissue affects millions of lives on our planet today.
The major message to everyone reading this article is to be aware that hypermobility of a finger (as in the photo) can be a reflection of changes within that patient that may warrant further investigation. Understanding that creating the necessary stability in the individual with chronic pain may not only be all about muscle strengthening, but it might entail some radical understanding and necessary treatment directed at the ligaments and joint capsules as well. This especially pertains to clinicians such as physical therapists and spine surgeons, who need to have a full and complete game plan when those “hypermobile” chronic pain patients walk into the office looking for long-term relief.
- Dall, B.E., Priest, B.; A Clinical Marker for Premenopausal Osteoporosis: Hypermobility of the Second Metacarpal phalangeal Joint, Today’s Therapeutic Trends: The Journal of New Developments in Clinical Medicine, Volume 10, Number 1, pages 22-37, 1992.
- Dall, B.E., Sacroiliac Joint Pain: For Tens of Thousands the Pain Ends Here. DallHouse Productions, Kalamazoo, Michigan. ISBN #s 978-0-9993804-2-0 (paperback), 978-0-9993804-0-6 (Kindle), 978-0-9993804-1-3 (Epub). 2017. Amazon.com.