Women with long ring fingers may be at greater risk of developing arthritis in their knees, researchers say.
Typically, women's index and ring fingers are a similar length. Men tend to have longer ring fingers.
But scientists have found that women with uncommonly long ring fingers had almost double the risk of osteoarthritis in the knee when compared to those with fingers of similar length.
Lead researcher Professor Michael Doherty said it was a new risk factor for the development of osteoarthritis.
"Specifically, women with the male pattern of length ratio - that is, ring finger relatively longer than the index finger - are more likely to develop knee osteoathritis.
"The underlying mechanism of the risk is unclear and merits further exploration."
For the research, the team from Nottingham University analysed the hands of 2,000 arthritis patients and 1,000 without arthritis in their sixties.
Researchers, whose findings are published in the journal Arthritis & Rheumatism, took X-rays of both hands of the patients and assessed the length of fingers using three methods.
These included a direct visual comparison of the two finger ends, the measured ratio from base to the tip of the upper finger joints and the measured ratio of the bone lengths.
Even after risk factors such as joint injury and a lack of exercise were taken into account, the higher risk of arthritis remained for women with long ring fingers.
This is the first study to examine the relationship between the two fingers and arthritis.
Previous research showed that women whose ring fingers are longer than their index fingers are generally better at sport.
It is not known why, but experts believe that genetic factors may play a part.
Others have suggested finger ratio is linked to exposure to the male hormone testosterone in the womb. This theory is based on the fact that there are different levels of testosterone and oestrogen in the womb of different mothers.
This is believed to have an effect on both brain development and finger length.
A longer ring finger has often been connected with greater pre-natal exposure to testosterone.
Scientists have also previously claimed that the relative length of fingers can reveal personality traits.
Researchers from the University of Liverpool found that if the index finger is a lot shorter than the ring finger, it might indicate a tendency for depression and homosexuality in men.
Women with a similar finger pattern were more likely to be lesbians, they said.
Meanwhile, a study in Canada, in 2005, found that the shorter the index finger the more likely it was that a child would be aggressive.
And last year, Bath University psychologists found children's exam results could be predicted by measuring the lengths of their fingers.
Those with ring fingers as long as index fingers were likely to favour numeracy, while those with shorter ring fingers were more adept at literacy tests.