Presence of a family history and excessive pressure on the first toe pad during walking in female subjects with pincer nails.

Abstract

Pincer nails (PN) are defined as a transverse overcurvature of the nail plate. Although there have been advancements in therapeutic approaches, the precise underlying mechanisms for the development of PN are still not fully understood. Currently, PN are assumed to develop due to lack of upward mechanical force on the toes. We developed a novel wireless device to observe detailed gait motion. We analyzed trends of gait motion in healthy individuals without PN, healthy individuals with PN without a family history of PN, and healthy individuals with PN and a family history of PN. We found that a family history of PN is an independent risk factor for PN, irrespective of gait motion. Moreover, healthy individuals with PN but without a family history of PN exhibit strong and concentrated pressure on the first toe pad during walking. In sum, a family history of PN and excess upward mechanical forces on the first toe pad during walking may be risk factors for the development of PN.