====== Wrinkly Fingers ====== Most people have experienced wrinkly finger syndrome - when fingertips turn paler and wrinkle after prolonged exposure to water. There are two theories on how the wrinkles develop - the ‘shrink’ model and the ‘swell’ model. Neither theory alone provides a full explanation. A 2017 study in the //Annals of biomedical engineering// provides fresh insight. The research team’s computational models suggest that both the ‘shrink’ model and the ‘swell’ model are //probably operating at the same time//. >“Everyone has experienced wrinkly fingers after an extended exposure to water. These wrinkles have been proposed as an evolutionary mechanism for a better grip of wet objects. However, besides experimental observations or mathematical theories, there is still not a clear agreement whether this is a result of the contraction of the hypodermis ( the ‘shrink’ model), the effect of epidermal swelling (the ‘swell’ model), or the coupling of both mechanisms.” But more research is still needed to fully explain the phenomenon. >“Without doubt, further experiments will help to close the debate about the origin of fingertip wrinkling.” See : [[https://upcommons.upc.edu/bitstream/handle/2117/103536/2016-ABE-SZ-blanc.pdf|Mechanics reveals the biological trigger in wrinkly fingers]] , P Sáez, AM Zöllner - //Annals of biomedical engineering//, 2017.