%0 Journal Article %T The influence of head impact threshold for reporting data in contact and collision sports: systematic review and original data analysis %J Sports medicine %D 2015 %A King, D. %A Hume, P. %A Gissane, C. %A Brughelli, M. %A Clark, T. %V 46 %N 2 %P 151-169 %X BACKGROUND: Head impacts and resulting head accelerations cause concussive injuries. There is no standard for reporting head impact data in sports to enable comparison between studies.

OBJECTIVE: The aim was to outline methods for reporting head impact acceleration data in sport and the effect of the acceleration thresholds on the number of impacts reported.

METHODS: A systematic review of accelerometer systems utilised to report head impact data in sport was conducted. The effect of using different thresholds on a set of impact data from 38 amateur senior rugby players in New Zealand over a competition season was calculated.

RESULTS: Of the 52 studies identified, 42 % reported impacts using a >10-g threshold, where g is the acceleration of gravity. Studies reported descriptive statistics as mean ± standard deviation, median, 25th to 75th interquartile range, and 95th percentile. Application of the varied impact thresholds to the New Zealand data set resulted in 20,687 impacts of >10 g, 11,459 (45 % less) impacts of >15 g, and 4024 (81 % less) impacts of >30 g.

DISCUSSION: Linear and angular raw data were most frequently reported. Metrics combining raw data may be more useful; however, validity of the metrics has not been adequately addressed for sport. Differing data collection methods and descriptive statistics for reporting head impacts in sports limit inter-study comparisons. Consensus on data analysis methods for sports impact assessment is needed, including thresholds. Based on the available data, the 10-g threshold is the most commonly reported impact threshold and should be reported as the median with 25th and 75th interquartile ranges as the data are non-normally distributed. Validation studies are required to determine the best threshold and metrics for impact acceleration data collection in sport.

CONCLUSION: Until in-field validation studies are completed, it is recommended that head impact data should be reported as median and interquartile ranges using the 10-g impact threshold. Keywords: Australian football, Rugby, Soccer

Language: en

%G en %I Adis International %@ 0112-1642 %U http://dx.doi.org/10.1007/s40279-015-0423-7