1. Reconstruction of head impacts in FIS World Cup alpine skiing
- Author
-
Roald Bahr, Kam-Ming Mok, Sophie Elspeth Steenstrup, Tron Krosshaug, and Andrew S. McIntosh
- Subjects
Male ,Motion analysis ,Video Recording ,Physical Therapy, Sports Therapy and Rehabilitation ,Angular velocity ,Kinematics ,03 medical and health sciences ,0302 clinical medicine ,Skiing ,Concussion ,medicine ,Craniocerebral Trauma ,Humans ,Orthopedics and Sports Medicine ,Head injury ,Biomechanics ,030229 sport sciences ,General Medicine ,Geodesy ,medicine.disease ,Sagittal plane ,Biomechanical Phenomena ,medicine.anatomical_structure ,Athletic Injuries ,Head (vessel) ,Female ,Head Protective Devices ,Head ,030217 neurology & neurosurgery ,Geology - Abstract
IntroductionPrior to the 2013/2014 season, the International Ski Federation (FIS) increased the helmet testing speed from 5.4 to 6.8 m/s for alpine downhill, super-G and giant slalom. Whether this increased testing speed reflects head impact velocities in real head injury situations on snow is unclear. We therefore investigated the injury mechanisms and gross head impact biomechanics in seven real head injury situations among World Cup (WC) alpine skiers.MethodsWe analysed nine head impacts from seven head injury videos from the FIS Injury Surveillance System, throughout nine WC seasons (2006–2015) in detail. We used commercial video-based motion analysis software to estimate head impact kinematics in two dimensions, including directly preimpact and postimpact, from broadcast video. The sagittal plane angular movement of the head was also measured using angle measurement software.ResultsIn seven of nine head impacts, the estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s (mean 8.1 (±SD 0.6) m/s, range 1.9±0.8 to 12.1±0.4 m/s). The nine head impacts had a mean normal to slope velocity change of 9.3±1.0 m/s, range 5.2±1.1 to 13.5±1.3 m/s. There was a large change in sagittal plane angular velocity (mean 43.3±2.9 rad/s (range 21.2±1.5 to 64.2±3.0 rad/s)) during impact.ConclusionThe estimated normal to slope preimpact velocity was higher than the current FIS helmet rule of 6.8 m/s in seven of nine head impacts.
- Published
- 2017