Call it hypermobility or call it double-jointedness: its effects range from "a curious deviation from the normal" to life threatening. A hypermobile joint is one whose range of motion (ROM) is beyond the 95th percentile for the general population.⁴ A hypermobile person is one with unusually large ROM in many or all joints. One definition, proposed by Beighton⁵ and often used in clinical studies, uses a 9-point scale:

• 1 point each side for passive dorsiflexion of the fifth finger beyond 90° with the forearm flat on a table

• 1 point each side for passive apposition of the thumb to the flexor aspect of the forearm

• 1 point each side for hyperextension of the elbow beyond 10°

• 1 point each side for hyperextension of the knee beyond 10°

• 1 point for forward flexion of the trunk so that the hands rest easily on the floor

There is some room for disagreement with this definition (for instance, a subject with loose hip joints but short hamstrings would fail the 5th test), but a high Beighton score does demonstrate that the person is unusually supple. Various investigators have found that between 2 percent and 38 percent of the subject group (college students, athletes, musicians, rheumatic British housewives, etc.) meet some or all of Beighton’s criteria. Hypermobility is seen more often in the young than the old, more often in women than men, and in all ethnic groups.

It is important to realize that hypermobility itself is a sign rather than a condition or a disorder. The question to ask during assessment is, "What is the cause of this hypermobility?" Most disease processes limit ROM rather than extend it. There are only a limited number of reasons for an especially supple joint:

• Joint geometry: a shallower-than-normal curvature in the articulating bone surfaces, or a thinner-than-normal layer of hyaline cartilage within the joint. If ROM is normally limited by a bony stop, the relative positions of stop and articulating surface may be somewhat displaced to permit hypermobility at that joint.

• Tissue biochemistry: the connective tissue that forms the joint capsule may contain extra elastin or else its collagen may have shorter-than-normal chains or fewer cross-linkages.

• Muscle tonality: there may be lower-than-normal muscle tension across the joint.

• Endocrine state: the person may produce unusual hormone levels (lower-than-normal anabolic steroids or heightened relaxin secretion).

• Exercise: long-term repetitive effort, as in Repetitive Stress Injury (RSI), yoga, or ballet, can extend the ROM. The most likely mechanism is by promoting some combination of factors 1 through 3.

• Trauma: injury to bone, joint capsule, or supporting musculature can leave a joint unable to withstand stresses that would be nominal for a normal joint. Two or more of these factors may combine to produce hypermobility at a specific joint.

Any of these direct causes can arise in turn from either benign or pathological processes. The most clearly documented pathologies are inherited or congenital biochemical lesions such as appear in the Ehlers-Danlos group of syndromes (EDS),6 Marfan syndrome,⁷ and Down syndrome. In all of these conditions, hypermobility is pronounced throughout the skeletal system. In most of them, there are additional connective tissue defects, such as highly elastic but fragile, easily bruised skin (all the EDS types) and the Mitral Valve Prolapse (MVP) problems suffered by people with Type III EDS.⁸

Of all the conditions described by Beighton (in reference 5), probably the most common is Familial Articular Hypermobility Syndrome (FAHS). He writes (p. 236):

The FAHS comprises generalized joint laxity without subluxations or dislocations, in the absence of involvement of the skin or other tissues. The FAHS may be innocuous and merely represent a source of innocent amusement to affected persons and onlookers alike by virtue of the opportunities afforded by "double jointedness." Conversely, frequent sprains, subluxations and dislocations may cause serious handicap. The overall presence or absence of these complications is fairly consistent from family to family; on this basis the FAHS has been divided into "uncomplicated" and "dislocating" types. Nonspecific limb pains occur in all forms and are often the predominant feature, especially in the rheumatological context. McKusick has suggested that these pains, which can be severe, may result from excessive stretching of the soft tissues consequent on joint hypermobility."

The hypermobile joint is often asked to withstand tensions in amounts or directions for which its fibrous capsule, tendons, and ligaments were not designed. Joint capsules have a rich nerve supply, so overstretching can bring on pain. Conversely, they have little or no direct blood supply, so they heal slowly when damaged.

When a joint is bent further than it was designed to, the damage may not be limited to the joint capsule and its attached ligaments. The hyperflexion or hyperextension may result in stretching or impingement of nerves that traverse the joint, producing radiating pain. Mechanical forces generated by increased leverage at the point of flexure may overstretch related tendons; compress tendons, ligaments, or bursae; or even disrupt the bony structure. The resulting micro- and macro-tears can lead to permanent injury.

Thus, a hypermobile joint is a joint in jeopardy, and a hypermobile person may (but may not) have some special medical concerns related to its cause. Keep in mind that a person may possess intrinsic hypermobility but may not display it

until tested for it. Reasons for such hidden hypermobility range from, "I didn’t know it was possible to move that way" to "Our people just don’t do things like that."

The Hypermobile Therapist

If the hypermobile person in the treatment room is the massage therapist, not the client, then additional considerations apply to designing the massage. The massage therapist makes a living from the same sort of repetitive joint-stressing motions that she would warn her hypermobile client against. Here are some basic principles for defending oneself against the same sorts of problems:⁹

• Don,t stretch the muscles around your own hypermobile joint(s). Strengthen them. There is nothing to be gained by loosening support of an already-unstable structure.

• Use all the alternative working surfaces you can. Develop ways to use your forearm (ulnar and volar surfaces), elbow (olecranon and epicondyles), soft fist, pisiform bone, knuckles, the ulnar border of your hand, and the dorsal surfaces of your proximal and middle phalanges. As a side benefit, some of those surfaces may fit some of the client’s problem areas better than fingertips do. Reserve thumbs and fingertips for strokes on areas for which no other working surface is suited.

• Support the working surface, either from the rear (finger or thumb behind active fingertip) or at both ends. For instance, when using the forearm, stabilize its distal end by holding your wrist with your other hand. If trigger point or accupressure work is to be done using the thumb tip for compression, support the thumb with the index finger. Better yet, switch to using a proximal interphalangeal knuckle of the third finger, supported from behind by the thumb.

• Keep unsupported joints in neutral position. Never apply compression with hyperextended digits, laterally deviated wrists, or sharp bends at wrist or thumb.

• Monitor your own body while you’re working on your client’s. If you feel torque at one of your joints, shift your position or add a support to eliminate it. Pressure should generally be exerted along the length of a bone, not across it.

From grounding foot to caring hand, the chain of joints is no stronger than its weakest link and no more robust than its most vulnerable component. An overworked joint can put a massage therapist out of business until it heals—and it may heal exceedingly slow. Because a hypermobile joint is even less stable than a normal one, it’s even more susceptible to mechanical stress and even more of a threat to the therapist’s continuing service. Prevention is by far the best medicine. The wise massage worker pays attention to body mechanics. The wise hypermobile massage worker is fanatic about it.

Rich Olcott, Ph.D., writes from Memphis, Tennessee, and can be reached at RichOlcott@compuserve.com

References

1. G. Jennings, Spangle, New York: MacMillan, 1987. A fictional but heavily researched description of circus life in the late 19th century. See also the Web page at http://www.escape.com/~silverbk/
contortion for biographies of performers who have been able to maintain their skills into their sixth and seventh decades.

2. A. F. Le Blanche, et al., "The Sacroiliac Joint: Anatomical Study in The Coronal Plane and MR Correlation," Surgical and Radiologic Anatomy Electronic Edition (1996), on the Web at http://science.springer.de/sra
/PAPERS/6018003/6018215.htm#gen13

3. Don McClain, D.C., private communication.

4. http://www.talk-101.com/users/planc, "The Double-Jointed Page."

5. Cited in P. Beighton, ed., McKusick’s Heritable Disorders of Connective Tissue, St. Louis: Mosby (1993), 5th Edition, p. 200.

6.  See http://stgenesis.org/~leigh/EDS
/facts.html for answers to frequently asked questions (FAQ) about EDS. See also http://stgenesis.org/EDS/
wrong.html for material suitable for a clinical worker who is not a physician.

7. http://www.familyvillage.wisc.edu
/lib_marf.htm is an FAQ resource for Marfan syndrome.

8. Beighton, Op Cit., is a compendium of articles on these conditions for the specialist. Also see [4] and R. Caillett, Soft Tissue Pain and Disability, Philadelphia: F. A. Davis, 1977 for material more suited to the lay reader.

9. L. Greene, Save Your Hands! Injury Prevention for Massage Therapists, Seattle: Infinity Press, 1995. A thorough discussion of massage-specific musculoskeletal problems and how to avoid them.