Table 1 Exposure, number of acute injuries and incidence of acute injuries on different turfs.

	Exposure, playing hours (%)			Number of injuries			Injury incidence, n/1000 playing hours (95% CI)
	Match	Training	Total	Match	Training	Total	Match	Training
Grass	27 627 (67)	45 417 (45)	73 044 (51)	230	56	286	8.3 (7.2 to 9.4)	1.2 (0.9 to 1.6)
Artificial turf	9402 (23)	30 577 (30)	39 979 (28)	82	37	119	8.7 (6.8 to 10.6)	1.2 (0.8 to 1.6)
Gravel	3905 (9)	21 251 (21)	25 156 (18)	26	16	42	6.7 (4.1 to 9.2)	0.8 (0.4 to 1.1)
Indoor	377 (1)	4165 (4)	4542 (3)	5	4	9	13.3 (1.6 to 24.9)	1.0 (0 to 1.9)
Total	41 311	101 410	142 721	343	113	456	8.3 (7.4 to 9.2)	1.1 (0.9 to 1.3)