Your fingers can point to many things – and not just physically. Scientists have discovered that people whose index finger is shorter than their ring finger run an elevated risk of getting osteoarthritis. The finding strengthens the curious biological importance that this index finger/ring finger ratio (known as 2D:4D) has on our lives. It has previously been associated with hormone levels, athletic prowess and sexual orientation.

Nottingham University researchers compared finger lengths of 2,000 osteoarthritis sufferers with those of 1,100 healthy individuals. Those with relatively long ring fingers – the pattern usually seen in men – were twice as likely to be in the osteoarthritis group. Women with this “male” finger ratio were particularly likely to have bad knees.

The researchers say that they are unsure why such an association exists, but it could be due to hormonal influences in the womb. Generally, a longer ring finger is thought to indicate higher exposure to prenatal testosterone. In women, the index finger is either similar in length or slightly longer than the ring finger.

This has led to various studies on finger ratios in sports people. A 2006 paper in the British Journal of Sports Medicine suggested that gifted sportswomen show a “male” 2D:4D. A separate study, from the University of Central Lancashire, indicated a fascinating correlation between finger ratios and footballing success in men. Professional footballers tend to exhibit longer ring fingers than the nonfootballing population, while the ratio is even more pronounced among international players.

Rather more controversially, the ratio has also been linked to sexual orientation. Lesbians are more likely to sport a “male” ratio than straight women, which supports the idea that sexual orientation is shaped by hormonal exposure in the womb.

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