title: A novel method for measuring in-shoe navicular drop during gait.
abstract: Analysis of foot movement is essential in the treatment and prevention of foot-related disorders. Measuring the in-shoe foot movement during everyday activities, such as sports, has the potential to become an important diagnostic tool in clinical practice. The current paper describes the development of a thin, flexible and robust capacitive strain sensor for the in-shoe measurement of the navicular drop. The navicular drop is a well-recognized measure of foot movement. The position of the strain sensor on the foot was analyzed to determine the optimal points of attachment. The sensor was evaluated against a state-of-the-art video-based system that tracks reflective markers on the bare foot. Preliminary experimental results show that the developed strain sensor is able to measure navicular drop on the bare foot with an accuracy on par with the video-based system and with a high reproducibility. Temporal comparison of video-based, barefoot and in-shoe measurements indicate that the developed sensor measures the navicular drop accurately in shoes and can be used without any discomfort for the user.
authors.affiliation: Signal Processing and Control Group, Department of Engineering, Aarhus University, Finlandsgade 22, Aarhus N 8200, Denmark. iha@simonk.dk
authors.forename: Simon L
authors.initials: SL
authors.lastname: Kappel
authors.forename: Michael S
authors.initials: MS
authors.lastname: Rathleff
authors.forename: Dan
authors.initials: D
authors.lastname: Hermann
authors.forename: Ole
authors.initials: O
authors.lastname: Simonsen
authors.forename: Henrik
authors.initials: H
authors.lastname: Karstoft
authors.forename: Peter
authors.initials: P
authors.lastname: Ahrendt
mesh_terms: D005528:Foot / Q000502:physiology; D005684:Gait / Q000502:physiology*; D006801:Humans; D009068:Movement / Q000502:physiology*; D012775:Shoes; D013639:Tarsal Bones / Q000502:physiology*
keywords: Danfoss PolyPower; capacitive strain sensor; dielectric electro active polymer (DEAP); foot dynamics; foot movement; gait analysis; multi-video sequence analysis; navicular drop