[B]Study associates shorter second than fourth digit with independent risk for knee osteoarthritis, especially among women[/B]
Index to ring finger length ratio (2D:4D) is a trait known for its sexual differences. Men typically have shorter second than fourth digits; in women, these fingers tend to be about equal in length. Smaller 2D:4D ratios have intriguing hormonal connections, including higher prenatal testosterone levels, lower estrogen concentrations, and higher sperm counts. Reduction in this ratio has also been linked to athletic and sexual prowess. Whether this trait affects the risk of osteoarthritis (OA), a progressive joint disease associated with both physical activity and estrogen deficiency, has not been examined. Until recently.