by Dr. David Borenstein M.D. updated 8/2021
I remember taking my kids to the circus and seeing a performance by gymnasts between the lions and the elephants. In the middle of their act, the gymnasts brought out a middle-sized box and placed it in the middle of the ring. First the top of the box flew open and then a hand appeared. Then came the other hand, an arm, another arm, a neck and head. Soon after, one leg unfurled and then the other. The person had been able to curl up all their limbs to fit all contorted into a relatively small box. Since I had trouble touching my knees when bending over, I was amazed at the flexibility of this individual. I was sure that they had EDS or hyper-mobility of their musculoskeletal system. I was sure they would have spine issues and would be seeing a spine specialist of some sort during their lives.
Hyper-mobility spectrum disorder is term used since a 2017 international conference to describe a variety of connective disorders associated with a musculoskeletal system that is too flexible. Joint hyper-mobility (JH)is common with one in five individuals with localized or generalized laxity. However, approximately 1 in 600 individuals have a symptomatic or disabling form of the disorder. In rheumatology offices, 3% of all patients have complaints associated with this disorder. JH is more prevalent in women and tends to decrease as individuals age.
No one specific abnormality has been discovered since there are multiple forms of this disorder. In many individuals an abnormality in the formation of collagen, a major of all our connective tissues, is present.
Hyper-mobility results in back pain in a minimum of 6% of individuals with JH with upwards of 23% demonstrating spinal deformity with radiographic evaluation. Many of these individuals have a prominence at the junction of the thoracic and lumbar spine resulting in a kyphoscoliosis.
In addition, recurrent joint sprains or tendon injuries are frequent complaints of individuals with JH. Some of these individuals have partial or full dislocations of joints including the shoulders, thumbs, ankles or hips. These events result in complex, widespread pain.
The presence of extensible tissues in other locations results in dysfunction in a number of organ systems. Individuals may have easy bruising. Pelvic floor weakness may result in bladder difficulties including stress incontinence. Gastrointestinal problems manifest as bloating, slow transit time, and constipation. The autonomic nervous system may be affected with postural tachycardia, dizziness, and passing out.
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The diagnosis of JH can be made by individuals who can bend at the waist with locked knees and place their palms flat on the floor, who bend their thumb to touch their forearm, or bend their fingers back to 90 degrees, or who hyperextend their elbows or knees to greater than 10 degrees. Combinations of these physical findings increase the possibility of JH as a diagnosis.
The treatment of JH is nonsurgical. Bracing and muscle strengthening exercises are used to prevent deformities. Swimming may strengthen muscles to help stabilize loose joints. Bracing of the spine may be worthwhile early in the course of the illness before scoliosis appears.
- Malfait F et al. The 2017 international classification of the Ehlers-Danlos syndromes. Am J Med Genet C Semin Med Genet 2017;175:8-26
- Grahame R. Hypermobility: an important but often neglected area within rheumatology. Nat Clin Pract Rheumatol. 2008; 522-524
- Mulvey MR et al. Modest association of joint hypermobility with disabling and limiting musculoskeletal pain: results from a large scale general population-based survey. Arthritis Care Res 2013;65:1325-1333
- Rombaut L et al. Medication, surgery, and physiotherapy among patients with the hypermobility type of Ehlers-Danlos syndrome