Hypermobility vs. HSD: Understanding Differences, Symptoms, and Management

What is the difference between hypermobility and HSD?

Joint hypermobility refers to the ability of a joint to move beyond its typical range of motion, whereas Hypermobility Spectrum Disorder (HSD) is a diagnosis given when hypermobility is accompanied by chronic symptoms like pain, fatigue, or instability, significantly impacting quality of life.

Understanding Joint Hypermobility

Joint hypermobility, often colloquially referred to as being "double-jointed," describes a condition where one or more joints can move beyond the normal, expected range of motion. This increased flexibility is primarily due to laxity in the ligaments and connective tissues surrounding the joints. It is a relatively common trait, present in a significant portion of the population, particularly in children, adolescents, and women.

Key characteristics of benign joint hypermobility include:

• Asymptomatic Nature: In many individuals, hypermobility causes no pain, discomfort, or functional limitations. It can even be advantageous for certain activities like dance, gymnastics, or playing musical instruments.
• Genetic Predisposition: The underlying cause is often genetic, affecting the structure of collagen, a primary protein in connective tissue.
• Assessment: The Beighton Score is a widely used, simple nine-point scale to assess generalized joint hypermobility. It evaluates the range of motion in the fingers, thumbs, elbows, knees, and trunk.

It's crucial to understand that hypermobility itself is not inherently a disorder or a problem. It becomes a concern when it leads to symptoms.

Beyond Hypermobility: Introducing Hypermobility Spectrum Disorder (HSD)

Hypermobility Spectrum Disorder (HSD) is a relatively new diagnostic term, established in 2017 by the International Consortium on Ehlers-Danlos Syndromes and Related Disorders. It replaced previous diagnoses like Joint Hypermobility Syndrome (JHS) and aims to provide a more specific and consistent framework for individuals who experience symptoms related to their hypermobility but do not meet the strict criteria for hypermobile Ehlers-Danlos Syndrome (hEDS), which is a distinct, more severe genetic connective tissue disorder.

HSD is diagnosed when an individual exhibits joint hypermobility along with chronic symptoms that significantly impact their daily life, and these symptoms cannot be explained by another medical condition. The "spectrum" aspect emphasizes the wide variability in the number, type, and severity of symptoms among affected individuals.

Key Distinctions: When Does Hypermobility Become HSD?

The fundamental difference between benign joint hypermobility and HSD lies in the presence and impact of symptoms.

• Asymptomatic vs. Symptomatic:

  • Hypermobility: Often asymptomatic; the individual has increased joint range of motion but experiences no pain, instability, or other related issues.
  • HSD: Characterized by chronic and often debilitating symptoms directly attributable to the hypermobility. These symptoms go beyond simple flexibility and negatively affect quality of life.

• Impact on Daily Life:

  • Hypermobility: Generally does not interfere with daily activities or require medical intervention.
  • HSD: Symptoms frequently lead to functional limitations, reduced participation in activities, and may necessitate lifestyle adjustments and ongoing medical management.

• Diagnosis:

  • Hypermobility: Identified by physical examination (e.g., Beighton score) and is a physical trait.
  • HSD: Requires a comprehensive clinical evaluation by a physician knowledgeable in hypermobility disorders. Diagnosis involves assessing the degree of hypermobility, the presence and severity of specific symptoms, and ruling out other conditions. It's a medical diagnosis, not just a description of flexibility.

• Need for Management:

  • Hypermobility: Typically requires no specific medical management.
  • HSD: Requires a multidisciplinary approach to manage symptoms, improve function, and prevent complications.

Common Symptoms Associated with HSD

Individuals with HSD can experience a wide array of symptoms, reflecting the systemic nature of connective tissue issues. These often extend beyond just the joints:

• Chronic Musculoskeletal Pain: This is one of the most common and debilitating symptoms. It can be widespread, affecting multiple joints and muscles, and may be neuropathic or myofascial in nature.
• Joint Instability: Frequent subluxations (partial dislocations) or full dislocations, leading to pain, swelling, and fear of movement.
• Fatigue: Often profound and disproportionate to activity, not relieved by rest. This is a significant contributor to reduced quality of life.
• Proprioception Deficits: Impaired body awareness and coordination, leading to clumsiness, frequent falls, or difficulty with balance.
• Autonomic Dysfunction (Dysautonomia): Manifests as issues with blood pressure and heart rate regulation, leading to symptoms like dizziness, lightheadedness, fainting (Postural Orthostatic Tachycardia Syndrome - POTS is common), palpitations, and temperature dysregulation.
• Gastrointestinal Issues: Symptoms such as irritable bowel syndrome (IBS), reflux, slow gastric emptying, and abdominal pain.
• Skin Manifestations: While typically less severe than in hEDS, skin may be soft, velvety, stretchy, or bruise easily.
• Pelvic Floor Dysfunction: Can include issues with bladder control, bowel movements, and pelvic pain.
• Headaches: Often chronic, including migraines or cervicogenic headaches.
• Anxiety and Depression: Higher prevalence due to chronic pain, fatigue, and the challenges of living with a chronic condition.

Diagnosis and Management

Diagnosing HSD is a clinical process, performed by a healthcare professional experienced in connective tissue disorders. It involves a thorough medical history, physical examination (including the Beighton Score), and a detailed assessment of symptoms. It's crucial to differentiate HSD from hEDS and other conditions that might cause similar symptoms.

Management of HSD is typically multidisciplinary and aims to alleviate symptoms, improve functional capacity, and enhance quality of life. Key components include:

• Physical Therapy: This is often the cornerstone of management. Focus is on strengthening muscles around unstable joints, improving proprioception, balance, and core stability, rather than stretching.
• Occupational Therapy: To help individuals adapt daily tasks and conserve energy.
• Pain Management: Strategies may include medication, complementary therapies, and education on pain coping mechanisms.
• Lifestyle Modifications: Pacing activities, ensuring adequate sleep, hydration, and nutrition.
• Psychological Support: To address the emotional impact of living with a chronic condition, including anxiety, depression, and fear of movement.
• Referrals: To specialists for specific symptoms (e.g., gastroenterologist for GI issues, cardiologist for POTS).

Implications for Exercise and Physical Activity

For individuals with HSD, exercise is not just beneficial but essential, though it requires a highly individualized and cautious approach.

• Strengthening Over Stretching: The primary goal of exercise for HSD is to build muscle strength and endurance to support and stabilize joints, thereby reducing pain and preventing injuries. Excessive stretching or activities that push joints into their hypermobile range should generally be avoided.
• Low-Impact Activities: Activities like swimming, cycling, elliptical training, and walking are often well-tolerated as they place less stress on joints.
• Proprioceptive Training: Exercises that challenge balance and body awareness (e.g., single-leg stands, tai chi, Pilates) are vital for improving joint control and reducing clumsiness.
• Core Stability: A strong core is fundamental for supporting the spine and larger joints, reducing overall strain.
• Pacing and Listening to Your Body: It's crucial to avoid overexertion, which can lead to symptom flares. Gradual progression and rest are key.
• Professional Guidance: Working with a physical therapist or exercise professional knowledgeable about HSD is highly recommended. They can design a safe and effective exercise program tailored to individual needs and limitations.

Conclusion

While joint hypermobility is a common physical trait that often causes no issues, Hypermobility Spectrum Disorder (HSD) represents the symptomatic end of the hypermobility spectrum. The presence of chronic pain, instability, fatigue, and other systemic symptoms that significantly impact daily life differentiates HSD from benign hypermobility. A proper diagnosis and a comprehensive, multidisciplinary management plan, with tailored exercise as a cornerstone, are crucial for individuals living with HSD to improve their quality of life and manage their symptoms effectively.