The difference between the lengths of a woman's index and ring fingers may indicate her sporting prowess, suggests research published ahead of print in the British Journal of Sports Medicine.
The finding supports other research indicating a possible link between this ratio and fertility, vulnerability to serious disease, intellectual ability, certain personality traits, and musical talent.
Most of the sporting research in this area has so far focused exclusively on men.
The researchers base their findings on x ray pictures of the right and left hands of 607 female twins, whose average age was 53. Most were right handed.
The second to fourth finger ratio was calculated by dividing the length of the index (second) finger by that of the (fourth) ring finger.
Study participants were also asked to rank their highest achievement in a wide range of individual and team sports, since the age of 11.
Participation levels were highest for swimming, cycling, tennis and running in descending order.
The association with finger ratio was highest for running, soccer, and tennis. The highest achievement in any sport was strongly linked to a low second to fourth finger ratio. Running ability was particularly associated with a low (male pattern) ratio.
It has been suggested that this finger ratio is established while in the womb, and that it is subject to the amount of exposure to sex hormones, say the authors. But the same group found that genetic factors, rather than womb environment, influenced finger ratio in a recent twin analysis.
The ratio tends to remain the same throughout life, the authors add, with men tending to have a lower ratio.