Glossary and Definitions
Box plot: A visual representation of the distribution of data using 5 key markers: The lower (Q1) and upper (Q3) quartiles indicated by the box with the median (Q2) indicated with the line in the box and the 10th and 90th percentiles shown with the whiskers that extend from the box.
- Q1: the 25th percentile indicating the data value below which 25% of the observations fall when the data is ordered from smallest to largest.
- Q2: also known as the median, which is the value in the middle of the grouped data range.
- Q3: the 75th percentile indicating the data value below which 75% of the observations fall when the data is ordered from smallest to largest.
- 10th Percentile: the data value below which 10% of the observations fall when the data is ordered from smallest to largest.
- 90th Percentile: the data value below which 90% of the observations fall when the data is ordered from smallest to largest.
Mean: The average number within the group of data, calculated by summing all the data points and dividing it by the total number of points.
Injury severity: Time based groupings based the duration of days lost from full training and playing, defined by the football-specific extension of the IOC consensus statement as 0 days, 1-3 days, 4-7 days, 8-28 days, 29-90 days, 91-190 days and >180 days.
Injury Incidence: The number of injuries that occur within a specific group (eg. athletes) over a defined period of time (eg. per 1000 hours of playing and training)
Return to play: Defined as the date of the first session that a player returns to full, unrestricted training with the team.
Injury: An injury begins once an athlete is unable to complete unrestricted training or compete in matchplay. The day the injury occurs is classed as ‘day 0’ and the following day will be ‘day 1’ of the injury.
Closed Injury: An injury is counted as closed when training is set to fully or it has been signed off
References:
Ekstrand, J., Krutsch, W., Spreco, A. et al. Time before return to play for the most common injuries in professional football: a 16-year follow up of the UEFA Elite Club Injury Study. Br J Sports Med. 2019;54: 421-426.
Fuller, C.W., Ekstrand, J., Junge, A. et al. Consensus statement on injury definitions and data collection procedures in studies of football (soccer) injuries. Br J Sports Med. 2006;40(3): 193-201.
Hallen, A., Tomas, R., Ekstrand, J. et al. UEFA Women’s Elite Club Injury Study: a prospective study on 1527 injuries over four consecutive seasons 2018/2019 to 2021/2022 reveals thigh muscle injuries to be most common and ACL injuries most burdensome. Br J Sports Med. 2024;58(3):128-135.
Orchard JW. Orchard Sports Injury and Illness Classification System (OSIICS) Version 15. La Trobe University. 2024.
Walden, M., Mountjoy, M., McCall, A. et al. Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020. Br J Sports Med. 2023;57:1341-1350.