J Michio Clark1, Kevin Adanty2, Andrew Post3, T Blaine Hoshizaki2, Jonathan Clissold4, Adrian McGoldrick5, Jerry Hill6, Aisling Ni Annaidh1, Michael D Gilchrist7. 1. School of Mechanical & Materials Engineering, University College Dublin Belfield, Ireland. 2. Faculty of Health Sciences, School of Human Kinetics, University of Ottawa, Canada. 3. St. Michael's Hospital, Canada; Faculty of Health Sciences, School of Human Kinetics, University of Ottawa, Canada; School of Mechanical & Materials Engineering, University College Dublin Belfield, Ireland. 4. British Eventing, United Kingdom. 5. Irish Horseracing Regulatory Board, Ireland. 6. British Horseracing Authority, United Kingdom. 7. School of Mechanical & Materials Engineering, University College Dublin Belfield, Ireland; Faculty of Health Sciences, School of Human Kinetics, University of Ottawa, Canada. Electronic address: michael.gilchrist@ucd.ie.
Abstract
OBJECTIVES: Equestrian helmets are designed to pass certification standards based on linear drop tests onto rigid steel surfaces. However, concussions in equestrian sports occur most commonly when a rider is thrown off a horse and obliquely impacts a compliant surface such as turf or sand. This paper seeks to elucidate the mechanics of such impacts and thereby propose corresponding thresholds for the occurrence of concussion that can improve equestrian helmet standards and designs. DESIGN: The present study examined the biomechanics of real-world equestrian accidents and developed thresholds for the occurrence of concussive injury. METHODS: Twenty-five concussive and 25 non-concussive falls in equestrian sports were reconstructed using a combination of video analysis, computational and physical reconstruction methods. These represented male and female accidents from horse racing and the cross-country phase of eventing. RESULTS: The resulting thresholds for concussion [59g, 2700rad/s2, 28rad/s, 0.24 (MPS), 6.6kPa and 0.27 (CSMD10) for 50% risk] were consistent with those reported in the literature and represent a unique combination of head kinematic thresholds compared to other sports. Current equestrian helmet standards commonly use a threshold of 250g and a linear drop to a steel anvil resulting in less than 15ms impacts. This investigation found that concussive equestrian accidents occurred from oblique impacts to turf or sand with lower magnitude and longer duration impacts (<130g and >20ms). This suggests that current equestrian helmet standards may not adequately represent real-world concussive impact conditions and, consequently, there is an urgent need to assess the protective capacity of equestrian helmets under real-world conditions.
OBJECTIVES: Equestrian helmets are designed to pass certification standards based on linear drop tests onto rigid steel surfaces. However, concussions in equestrian sports occur most commonly when a rider is thrown off a horse and obliquely impacts a compliant surface such as turf or sand. This paper seeks to elucidate the mechanics of such impacts and thereby propose corresponding thresholds for the occurrence of concussion that can improve equestrian helmet standards and designs. DESIGN: The present study examined the biomechanics of real-world equestrian accidents and developed thresholds for the occurrence of concussive injury. METHODS: Twenty-five concussive and 25 non-concussive falls in equestrian sports were reconstructed using a combination of video analysis, computational and physical reconstruction methods. These represented male and female accidents from horse racing and the cross-country phase of eventing. RESULTS: The resulting thresholds for concussion [59g, 2700rad/s2, 28rad/s, 0.24 (MPS), 6.6kPa and 0.27 (CSMD10) for 50% risk] were consistent with those reported in the literature and represent a unique combination of head kinematic thresholds compared to other sports. Current equestrian helmet standards commonly use a threshold of 250g and a linear drop to a steel anvil resulting in less than 15ms impacts. This investigation found that concussive equestrian accidents occurred from oblique impacts to turf or sand with lower magnitude and longer duration impacts (<130g and >20ms). This suggests that current equestrian helmet standards may not adequately represent real-world concussive impact conditions and, consequently, there is an urgent need to assess the protective capacity of equestrian helmets under real-world conditions.
Authors: James R Funk; Andrew S McIntosh; Chris Withnall; Michael Wonnacott; Ron Jadischke Journal: Ann Biomed Eng Date: 2022-07-25 Impact factor: 4.219
Authors: Madelen Fahlstedt; Fady Abayazid; Matthew B Panzer; Antonia Trotta; Wei Zhao; Mazdak Ghajari; Michael D Gilchrist; Songbai Ji; Svein Kleiven; Xiaogai Li; Aisling Ní Annaidh; Peter Halldin Journal: Ann Biomed Eng Date: 2021-01-21 Impact factor: 3.934