Thumb hypermobility is when a person’s thumb joint has an unusually large range of movement. Some people may experience mild to severe joint pain and require treatment.
Joints are areas of the body, or a junction, where two bones meet. Most joints bend, allowing the area to move. However, some people may have overly flexible joints. People may sometimes refer to this as being double-jointed, even though there is no second joint, but simply that the joint moves outside of its joint range of motion.
This article examines the symptoms, associated conditions, causes, diagnosis, and treatment of hypermobile thumbs. It also discusses other joints that can be double-jointed.
Joint hypermobility usually occurs in children and young people. As the joints become stiffer with age, hypermobility symptoms can also occur later in life. A collagen deficiency
Around 1 in 10 people with hypermobility may have symptoms ranging from mild to disabling, varying over time.
These symptoms can include:
- pain and stiffness in the thumb joints and muscles, most prominent at the end of the day and after physical activity
- clicking thumb joints
- thumb joint dislocations
Hypermobility of the thumb has not been the focus of specific research, but it can affect other finger joints.
Joint hypermobility tends to run in families, so a person may be unable to prevent it from occurring.
Other factors that may contribute to double-jointed thumbs include:
- Collagen structure: Collagen is present throughout the body and is the connective tissue that links two bones together at a joint. If the structure of collagen alters, it may not be as strong around the thumb joint. These changes to collagen may occur as a result of genetics.
- The shape of bond ends: The bone shape determines how far a person moves their thumb or other areas. If a person has a shallow thumb socket in which the bone moves around, it will make that joint much more flexible.
- Muscle tone: A child with doubled-jointed thumbs will likely have low muscle tone — hypotonia — which could mean they can bend their thumb joints more than usual.
- Sense of joint movement — proprioception: Some people with joint hypermobility may have abnormal joint movement and can sense an overstretched joint. This gives them a wider range of movement. People may be
less precisewhen estimating their hand’s position relative to visible peripheral reference locations.
In a small number of cases, joint hypermobility may relate to a more serious underlying condition that a child will often inherit from a parent.
The following associated conditions can cause joint hypermobility.
Hypermobile Ehlers-Danlos syndrome (EDS)
Hypermobile EDS, which many experts now consider joint hypermobility syndrome, affects the connective tissues. Estimates suggest it occurs in 1 in every 100–200 people. This condition causes the joints to stretch more than usual, causing extra flexibility and risk of injury.
People who have hypermobile EDS may be at risk for other symptoms, such as:
- digestive issues
- bladder problems
- easy bruising
- joint issues such as arthritis and dislocation
- issues with skin healing
There are also other possible complications:
- There is a strong association between several forms of cardiovascular dysfunction and joint hypermobility or EDS.
- Gastrointestinal manifestations may
- There is a
stronglink between pelvic organ prolapse and joint hypermobility.
Similar to EDS, Marfan syndrome affects the body’s connective tissues.
The condition may cause hypermobile joints and physical characteristics, referred to as Marfanoid habitus, such as increased height and unusually long limbs, fingers, and toes.
It may also cause potentially serious issues affecting the heart and eyes.
Osteogenesis imperfecta is a rare condition that doctors refer to as brittle bone disease as it causes fragile bones.
Some forms of the condition can also cause joint hypermobility, along with a range of other health issues.
Recent research also suggests a possible correlation between attention deficit hyperactivity disorder, autism, and joint hypermobility. However, more research still needs to confirm the correlation across more study samples.
A doctor will be able to make a diagnosis by:
- asking questions about symptoms, if any
- taking a family history
- ruling out other conditions
- examining joints
- assessing pain levels
Beighton score to measure hypermobility
A doctor will usually test a person’s joint flexibility and range of motion using the Beighton score. However, a medical professional will not solely rely on this method to confirm a diagnosis.
The scoring system
The Beighton score involves a series of five tests. The results add up to a total of nine points.
A person scores for the following criteria:
- can place their palms on the ground while standing with their legs straight
- each elbow that bends backward
- each knee that bends backward
- each thumb that touches the forearm when bent backward
- each little finger that bends backward beyond 90 degrees
Based on the above, if a person scores four or more, they likely have joint hypermobility.
There are also major and minor Brighton criteria:
The major Brighton criteria include if a person:
- currently has a Beighton score of four or more
- had previous Beighton score of four or more
- has joint pain for longer than 3 months in four or more joints
The minor Brighton criteria include if a person has:
- a Beighton score of 1–3 or a Beighton score of 0–3 if they are over 50 years
- joint pain for longer than 3 months up to three joints
- dislocation or partial dislocation of more than one joint, or the same joint more than once
- three or more injuries to soft tissues
- any Marfanoid habitus characteristics
- thin and stretchy skin
- any eye-related symptoms
Final diagnosis criteria
According to the Brighton criteria, a person has joint hypermobility if they have:
- two major criteria
- one major and two minor criteria
- four minor criteria
- two minor criteria and a close relative, such as a parent, has joint hypermobility
Most people with double-jointed thumbs will not experience many issues and will not require any medical treatment or support.
However, people who may experience more severe symptoms may require methods to ease pain and discomfort.
Treatment mainly focuses on improving muscle strength to protect the thumb joints, which can help in the following ways:
- decreasing pain
- reducing the risk of dislocations
- improving muscle strength and fitness
General pain management
To help ease thumb joint pain and stiffness, people can use heat methods, such as warm baths or hot water bottles.
Management strategies for chronic pain associated with joint hypermobility
- physical therapy
- pain-relieving medications
- durable medical equipment such as cushions, compressive garments, and braces
Experts can also provide support groups, educational programs, and information.
Below are some common questions on hypermobile thumb.
How do you tell if you are double-jointed in your thumb?
A person may have a double-jointed thumb if they can put their arm out straight with the palm facing down and the wrist fully bent downward and push the thumb back to touch the forearm.
How rare is a double-jointed thumb?
Research suggests that hypermobility affects 1 in 4 people, but there is limited evidence on the statistics for those affected by thumb hypermobility.
Is it usual to have a double-jointed thumb?
Joint hypermobility causes a person to have an unusually large range of movement in a particular joint, such as a thumb. It usually runs in families, so if one parent has it, 1 in 2 children will also have it.