Research overview: the purring and bone-healing hypothesis

A widely repeated idea holds that the low frequencies of cat purring stimulate bone density and tissue repair, sometimes invoked to explain why cats purr when injured or stressed. This overview surveys the origins and status of that hypothesis, which draws on general research showing that low-frequency mechanical vibration can influence bone in some experimental settings. It distinguishes that broader biomechanics literature from direct evidence in cats, which is essentially absent: no controlled study has shown purring heals feline tissue. The survey treats the healing claim as an intriguing but unproven hypothesis, contrasting it with better-supported functions of purring such as care solicitation and self-soothing, and it cautions against presenting the healing idea as established fact in the absence of feline-specific experimental data.