Table 1.

Descriptions of the studies used in the meta-analyses.

ID	Study	Condition	Gender	Age	Subjects	Study duration	Exposure (hr)	Injuries	Notes
1	Aoki et al. [6]	Both	Male	Youth	332 players	12 months	106,783	484	Ages 12–17 years. Injury location and type reported for training only.
2	Bjørneboe et al. [7]	Both	Male	Adult	14 clubs	4 seasons	261,541	1067	Professional teams in the Norwegian Tippeligaen.
3	Ekstrand et al. [8]	Both	Both	Adult	767 players	Followed teams for 4–38 months	246,475	1492	European elite players. Included “slight” injuries that required players to miss <1 day (~2% of total injuries). Since these could not be extracted, they were included in the present study.
4	Ekstrand et al. [9]	Both	Male	Adult	492 players	Followed teams for 4–32 months	82,874	449	European professional players. Compared two cohorts of players. The cohort of players that trained and played exclusively on grass were omitted from the current study.
5	Fuller et al. [10]	Match	Both	Adult	116 teams 126 teams	1st season 2nd season	79,253	1794	US College players. Utilized the NCAA Injury Surveillance System.
6	Fuller et al. [11]	Training	Both	Adult	116 teams 126 teams	1st season 2nd season	545,842	1592	US College players. Utilized the NCAA Injury Surveillance System.
7	Soligard et al. [12]	Match	Both	Youth	>68,000 players	4 occasions of a single tournament	62,597	2454	Norway Cup youth tournament. Matches played over six consecutive days. Ages 13–19 years. Data for male and female players were pooled.
8	Steffen et al. [13]	Both	Female	Youth	2020 players	8 months	113,023	405	Under-17 age group.