Ehlers Danlos Syndrome, Marfan Syndrome, and Hypermobility Spectrum Disorder

You may notice that some people are very stiff while others are very mobile or flexible, perhaps you even know someone with a party trick of doing the splits or another feat of flexibility? While some of this could be from stretching there are also genetic components that play a role.  We all lie somewhere on the spectrum of mobility, and why flexibility can be a great party trick often comes with other issues, mainly decreased stability.

An image to visualize high joint mobility, commonly known as hypermobility, is a cooked spaghetti noodle. A cooked noodle has a lot of movement, BUT little to no structure to help support it. In terms of joints, this may look like frequent partial or full dislocations, rolling your ankle frequently, or struggling to maintain form during strength training and movement. 

In the discussion below we will discuss:

• How Hypermobility is assessed
• The physiological aspects that affect the mobility of a joint
• Genetic factors that affect an overall joint mobility
• Common problems with high joint mobility

Assessing Hypermobility:

Hypermobility is commonly assessed by the Beighton Scale, a 9-point scale that measures the pinky knuckles, thumbs, elbows, knees, and spine (8).

• Pinkies:

• Thumbs:

Elbows:

• Knees:

• Spine:

**Photos borrowed from Ehlers-Danlos Society (8). **

It is worth noting that the range of motions of joints may change over time due to arthritis and joint inflammation. Also, the Beighton Scale is one piece of a diagnosis depending on your specific situation. If you are wondering about your hypermobility, I suggest seeking advice from a medical professional.

First, what is joint mobility?

A joint is a place where two parts of the skeleton meet, joint mobility refers to the movement of a joint.  Each joint has its normal range of motion and directions of movement. 

There are two types of mobility.

• Active: To actively move your body into this position.  Ex. Lifting your leg as high as possible
• Passive: Using gravity or other forces, not muscular, to move your body.  Ex. Bending over, letting gravity pull you down, to touch or reach towards the ground. 

The physiology of mobility:

There are three categories of joints in the body: fibrous, cartilaginous, and synovial (2). 

1. Fibrous joints are held together with fibrous tissue and have very little movement.
2. Cartilaginous joints are where adjacent bones are joined by cartilage; they have little movement.
3. Synovial Joints are what we often think of as joints, they are freely moveable and are classified based on the shapes of the joints. 

Synovial Joints are held together with multiple types of connective tissues attached to the adjoining bones, as the bones do not touch.  Cartilage covers the bone surfaces, while tendons, ligaments, periosteum, and muscles help to stabilize these joints.  While muscles do not attach directly, they attach to tendons which are attached to the bones of the joint and thus play a role in the stability and movement of a joint. (2)

The mobility of a joint is related to the ability of the joint to move or be moved.  Thus, the length and amount of stretch that tendons, ligaments, and muscles have affected the ability of the joint to move without resistance. 

Genetic Components:

While this area is still in need of more research; 7 genetic markers have been associated with a range of motion and muscle stiffness and 18 associated with joint laxity so far (1).  These factors account for some of the variations we see in flexibility. 

Some of the genetic variations are related to diseases that have been shown to affect joint mobility.  These include Ehlers Danlos Syndrome (EDS), Marfan Syndrome, and Hypermobility Spectrum Disorders. 

EDS: A group of related disorders caused by genetic issues affecting collagen, a structural component of connective tissues including bones, skin, tendons, ligaments, cartilage, etc.  Depending on the subgroup, issues are due to either poor strength in collagen or the lack of necessary normal collagen. (3)  Either affects tissue where collagen is present, including tendons, ligaments, and muscles.  These changes in collagen create more laxity of the tissue; thus, more flexibility and less stability.

Hypermobility Spectrum Disorders: A range of disorders that includes Hypermobile Ehlers Danlos Syndrome, Hypermobility Syndrome, and everything in between.  While both relate to changes in collagen, hypermobility syndrome is isolated to an increase of mobility in the joints while hypermobile Ehlers Danlos Syndrome includes a range of other symptoms.  (6)

Marfan Syndrome: A genetic disorder affecting connective tissue due to changes in the protein.  Connective tissue supports bone, muscles, organs, and tissues in the body and is important for supporting joint stability (4). Those with Marfan Syndrome commonly have joint hypermobility and instability (5).

The genetic disorders listed above affect joint stability due to the changes in tendons, ligaments, and muscles; meaning that those affected by them likely have a high amount of flexibility and a low amount of joint stability.

Common issues with too much flexibility:

There are a variety of problems that can occur for this who have highly mobile joints, and a high amount of flexibility (5).  They include:

• Frequent partial or full dislocations
• Joint pain
• Joint swelling
• Joint instability
• Arthritis (7)
• Muscle stiffness and tightness (the body’s effort to stabilize)

These issues can range from easily managed to Chronic Pain that inhibits you to participate in normal activities. While genetics cannot be altered, so far at least, there are options in how to manage and improve issues from hypermobility.

So, what is helpful?

Learning to stabilize joints by gaining muscular strength helps decrease pain AND stabilize joints.  Muscular strength helps by improving joint stability and control when connective tissue like tendons and ligaments have more stretch than normal. This helps to maintain normal patterns of movement in the joint, which in turn decreases pain, swelling, dislocations, and arthritis. Making strength the long-term solution to improving the negative impacts of too much flexibility.

Interested in learning what to avoid and how to gain strength with hypermobility? 

Stay tuned for my next post to learn how!

Resources:

1. Genetics of flexibility – ScienceDirect
2. Overview of Joint Anatomy and Physiology: A Basis for Understanding and Assessing Rheumatic Conditions (sagepub.com)
3. Ehlers Danlos Syndromes – NORD (National Organization for Rare Disorders) (rarediseases.org)
4. What is Marfan Syndrome? Symptoms & Causes | NIAMS (nih.gov)
5. Hypermobility Syndromes: Marfan’s, Ehlers-Danlos – Rheumatology Advisor
6. hEDSvHSD_tinkle edits_3142017 (ehlers-danlos.com)
7. Ehlers Danlos Syndromes | Arthritis Foundation
8. Assessing Joint Hypermobility – The Ehlers Danlos Society : The Ehlers Danlos Society (ehlers-danlos.com)