What does a bendy thumb mean?
Some people have thumbs that are hypermobile. This means they bend backward beyond the typical range. The medical term for hitchhiker’s thumb is distal hyperextensibility. It is also known as Z-shaped deformity of the thumb. Hitchhiker’s thumb is not painful and does not make it harder to use your hands.
What is the difference between a hitchhiker’s thumb and a normal thumb?
Some people have “hitchhiker’s thumbs,” which bend backwards with a large angle between the two segments (phalanges). The myth is that there are just two kinds of thumbs, straight thumbs (S) and hitchhiker’s thumbs (H), and the trait is controlled by a single gene with two alleles, with the allele for S being dominant.
How far can fingers bend back?
These joints allow for fine motor control, and in most people can flex about 45 or 50 degrees, and more for some when the finger is fully bent. The DIP joint can also extend or bend backwards anywhere from 10 to 25 degrees. The most proximal finger joints are called the metacarpophalangeal joints, or MCP for short.
Is a straight thumb dominant or recessive?
Dominance requires one copy of the dominant allele to be expressed and a straight thumb is usually deemed to be a dominant characteristic, even though the inheritance is complicated. Other examples of dominant traits are widow’s peak, detached earlobes, etc.
Why are some babies born with an extra thumb?
The exact cause is unknown. A baby’s hand starts forming early in the first trimester of pregnancy as a “limb bud” that looks like a paddle or mitten. As development continues, the limb bud divides into fingers. A split thumb occurs when this process of division continues a little longer than normal.
Is clubbed thumb rare?
The finger may be curved so much that it overlaps with other fingers. The bent finger usually functions fine and doesn’t hurt, but its appearance can make some children self-conscious. Clinodactyly is uncommon, affecting about 3 percent of babies born in the general population.
How rare is triple jointed?
It can affect one or more joints throughout the body. Hypermobile joints are common and occur in about 10 to 25% of the population, but in a minority of people, pain and other symptoms are present.
How rare is double-jointed?
Hypermobility (more commonly called being double-jointed) affects about 20% of people. An orthopaedic surgeon explains the cause and when hypermobility can be a problem.
How do I get rid of brachydactyly?
In extreme and very rare cases, surgery may be used to treat brachydactyly. Plastic surgery may be used for cosmetic purposes, or in rare cases, to improve functionality. Many who need surgery will have brachydactyly along with another condition. Surgery may include an osteomy, which cuts the bone.