Hypermobility: Prevalence, Types, Spectrum, and Management

Is hypermobility rare?

No, hypermobility is not rare; it is a relatively common trait, present in a significant portion of the general population, though its prevalence varies widely based on age, sex, ethnicity, and diagnostic criteria.

Understanding Hypermobility: More Than Just Being "Double-Jointed"

Joint hypermobility refers to the ability of a joint to move beyond its normal physiological range of motion. Often colloquially described as being "double-jointed," it is a characteristic rooted in the inherent laxity of connective tissues, primarily ligaments and joint capsules, which provide stability to our joints. While bone shape can also play a role, the elasticity and extensibility of these soft tissues are the primary determinants.

It's crucial to distinguish between different facets of hypermobility:

• Joint Hypermobility: The physical trait of having joints that move beyond typical limits.
• Generalized Joint Hypermobility (GJH): When this laxity affects multiple joints throughout the body.
• Hypermobility Spectrum Disorder (HSD): When hypermobility leads to symptoms like chronic pain, instability, or fatigue, but does not meet the full diagnostic criteria for a more specific connective tissue disorder.
• Hypermobility Ehlers-Danlos Syndrome (hEDS): A specific, hereditary connective tissue disorder with hypermobility as a prominent feature, often accompanied by a broader range of systemic manifestations.

The Prevalence of Hypermobility: Not as Rare as You Might Think

Far from being rare, joint hypermobility is a common finding in the general population. Estimates of its prevalence vary significantly, typically ranging from 10% to 25% in adults and even higher in children, depending on the population studied, the diagnostic tools used (e.g., Beighton score cut-offs), and the specific criteria applied. Some studies suggest figures as high as 30% or more in certain demographics.

Several factors influence the observed prevalence:

• Age: Hypermobility tends to be more prevalent in childhood and adolescence, often decreasing with age as connective tissues naturally stiffen.
• Sex: Females are consistently found to have a higher prevalence of hypermobility than males, often by a ratio of 2:1 or more. This is thought to be due to hormonal influences (e.g., estrogen and relaxin) on collagen metabolism.
• Ethnicity: Some ethnic groups, particularly those of Asian or African descent, have shown higher rates of hypermobility compared to Caucasian populations.
• Genetics: There is a strong hereditary component to hypermobility, with a tendency to run in families.
• Activity Level and Sport: Athletes involved in sports requiring extreme flexibility (e.g., gymnastics, dance, swimming) may either be naturally hypermobile, or their training may induce increased joint range of motion over time.

Generalized Joint Hypermobility vs. Localized Hypermobility

Hypermobility can manifest in different ways:

• Generalized Joint Hypermobility (GJH): This refers to laxity across multiple joints throughout the body. It is often assessed using standardized tools like the Beighton Score, which evaluates the flexibility of specific joints (knees, elbows, thumbs, pinky fingers, and lumbar spine). A certain score (e.g., 4/9 or 5/9) indicates GJH.
• Localized Joint Hypermobility: In some individuals, hypermobility may be limited to one or a few specific joints, such as a single shoulder, knee, or finger. This can be congenital or acquired due to repetitive movements, injury, or specific athletic training.

The Spectrum of Hypermobility: From Benign to Pathological

While common, hypermobility exists on a broad spectrum, with varying implications for an individual's health and functional capacity.

• Benign Joint Hypermobility (BJH): Many individuals with hypermobility experience no pain, instability, or functional limitations. For them, it is simply a physical trait that may even confer advantages in certain activities.
• Hypermobility Spectrum Disorder (HSD): This diagnosis is given when individuals experience symptoms directly related to their hypermobility (e.g., chronic joint pain, recurrent sprains, subluxations, fatigue, proprioceptive dysfunction) but do not meet the strict diagnostic criteria for Hypermobility Ehlers-Danlos Syndrome (hEDS). HSD can significantly impact quality of life.
• Hypermobility Ehlers-Danlos Syndrome (hEDS): This is a genetic connective tissue disorder characterized by generalized joint hypermobility alongside a specific set of systemic manifestations (e.g., skin hyperextensibility, tissue fragility, gastrointestinal issues, autonomic dysfunction). It requires a comprehensive clinical diagnosis by a specialist.

Implications for Movement and Exercise

For fitness enthusiasts and personal trainers, understanding hypermobility is critical, as it dictates appropriate exercise strategies.

Potential Advantages:

• Increased Flexibility: A greater range of motion can be advantageous in sports like gymnastics, dance, or martial arts.
• Enhanced Performance: Certain movements may be easier to achieve.

Potential Disadvantages and Risks:

• Joint Instability: Lax ligaments provide less passive support, increasing the risk of subluxations (partial dislocations) and full dislocations.
• Chronic Pain: Repetitive micro-trauma from unstable joints or compensatory muscle tension can lead to chronic pain.
• Proprioceptive Deficits: Hypermobile individuals often have reduced proprioception (the body's sense of joint position), further increasing instability risk.
• Increased Risk of Injury: Sprains, strains, and overuse injuries are more common.
• Fatigue: The body may expend more energy to stabilize hypermobile joints.

Exercise Considerations for Hypermobile Individuals:

• Prioritize Stability and Strength: Focus on strengthening the muscles surrounding hypermobile joints to provide active stability. This includes compound movements and targeted accessory work.
• Avoid End-Range Passive Stretching: While maintaining functional flexibility is important, excessive passive stretching can further destabilize joints and should generally be avoided. Focus on active flexibility within a stable range.
• Emphasize Controlled Movement: Slow, controlled, and eccentric movements are beneficial for building strength and improving proprioception.
• Proprioceptive Training: Incorporate balance exercises, unstable surfaces (if appropriate and safe), and single-leg drills to enhance joint position sense.
• Core Stability: A strong core is fundamental for providing proximal stability, which benefits all appendicular joints.
• Low-Impact Activities: Activities like swimming, cycling, or elliptical training can be gentler on joints.
• Listen to Your Body: Pain is a warning sign. Individuals with hypermobility should be particularly attuned to discomfort and avoid pushing into painful ranges.
• Professional Guidance: For symptomatic individuals, working with a physical therapist or exercise physiologist experienced in hypermobility is highly recommended to develop a safe and effective program.

Assessment and Diagnosis

For individuals concerned about their hypermobility, particularly if it's causing symptoms, a professional assessment is crucial.

• Beighton Score: This is a quick and simple clinical assessment tool used to screen for generalized joint hypermobility. It assesses five maneuvers, scoring each side of the body, for a maximum score of 9.
• Clinical Evaluation: A comprehensive evaluation by a doctor, physical therapist, or rheumatologist is necessary to differentiate between benign hypermobility, HSD, and hEDS, and to develop an appropriate management plan.

Conclusion: A Common, Yet Complex, Trait

In summary, hypermobility is not rare; it is a common characteristic found in a significant portion of the global population. While often benign, its presence necessitates a thoughtful approach to physical activity and exercise. Understanding its nuances – from generalized versus localized presentation to its spectrum from asymptomatic flexibility to symptomatic disorders like HSD and hEDS – empowers individuals and fitness professionals to make informed decisions that promote joint health, stability, and overall well-being. Recognizing hypermobility as a common, rather than rare, trait allows for proactive strategies to manage its potential challenges and harness its potential advantages.