Principal Investigators: Stephen C. Johnson, Ph.D. and Richard M. Greenwald, Ph.D.
Institution: Orthopedic Biomechanics Institute, Salt Lake City, UT. and National Institute of Sports Science and Safety, Providence, RI
Abstract: A field study was performed using Freestyle aerial ski jumpers to determine the incidence of head impact (slapback) and to record head acceleration data during slapback episodes for the 1994-95 and 1995-96 winter seasons. A total of 382 slapbacks were recorded from 2352 jumps for an observed slapback incidence of 16.2%. Head acceleration data were recorded for five slapback events. Maximum head acceleration magnitudes for the five impacts ranged from 27 to 92 g’s and impact durations ranged from 12 to 96 msec. Standard severity indices including the Gadd Severity Index (GSI) and Head Injury Criteria (HIC) were calculated from the resultant acceleration signal and ranged from 57 to 223, and 21 to 159, respectively, which are considered low in terms of life threatening injury levels.
Mechanisms of Head Injury During Freestyle Ski Jumping: A Biomechanical Analysis Publications 1) Mecham MD, Greenwald RM, Macintyre JG, Johnson SC
Incidence and Severity of Head Impact During Freestyle Aerial Ski Jumping, accepted for publication in Journal of Applied Biomechanics, April, 1998.
Mecham MD, Greenwald RM, Macintyre JG, Johnson SC: Incidence and Severity of Head Impact During Freestyle Aerial Ski Jumping. 2nd World Congress for Sports Trauma AOSSM Annual Meeting, June 1996.
Greenwald RM, Mecham MS: Biomechanics and NeuroPhyschological Effects of Head Impact Druing Freestyle Aerial Ski Jumping. United States Olympic Committee, $12,509. September 1997-April 1998.