title: Primary mechanical factors contributing to foot eversion moment during the stance phase of running.
abstract: Rearfoot external eversion moments due to ground reaction forces (GRF) during running have been suggested to contribute to overuse running injuries. This study aimed to identify primary factors inducing these rearfoot external eversion moments. Fourteen healthy men ran barefoot across a force plate embedded in the middle of 30-m runway with 3.30 ± 0.17 m · s-1. Total rearfoot external eversion/inversion moments (Mtot) were broken down into the component Mxy due to medio-lateral GRF (Fxy) and the component Mz due to vertical GRF (Fz). Ankle joint centre height and medio-lateral distance from the centre of pressure to the ankle joint centre (a_cop) were calculated as the moment arm of these moments. Mxy dominated Mtot just after heel contact, with the magnitude strongly dependent on Fxy, which was most likely caused by the medio-lateral foot velocity before heel contact. Mz then became the main generator of Mtot throughout the first half of the stance phase, during which a_cop was the critical factor influencing the magnitude. Medio-lateral foot velocity before heel contact and medio-lateral distance from the centre of pressure to the ankle joint centre throughout the first half of the stance phase were identified as primary factors inducing the rearfoot external eversion moment.
authors.affiliation: a Faculty of Sports and Health Sciences , Fukui University of Technology , Fukui , Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Tsujimoto
authors.affiliation: b Faculty of Sports and Health Science , Fukuoka University , Fukuoka , Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nunome
authors.affiliation: c Faculty of Health and Medical Sciences , Aichi Shukutoku University , Nagakute , Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ikegami
mesh_terms: D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena; D012090:Cumulative Trauma Disorders / Q000503:physiopathology; D005528:Foot / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D011312:Pressure; D012420:Running / Q000502:physiology*; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: Rearfoot eversion; ground reaction force; moment; running; stance phase