TABLE A4.
Frequency and Rate of Game-Related High School Football Injuries Between Artificial Turf Infill Systems by Cleat Design, Environmental Factors, and Turf Agea
| Variable | Infill Weight | |||||||
|---|---|---|---|---|---|---|---|---|
| ≥9.0 lb/ft2
(n = 528) |
6.0-8.9 lb/ft2
(n = 521) |
3.0-5.9 lb/ft2
(n = 525) |
0.0-2.9 lb/ft2
(n = 263) |
|||||
| n | IIR (95% CI) | n | IIR (95% CI) | n | IIR (95% CI) | n | IIR (95% CI) | |
| Cleat design | ||||||||
| 7-studded removable cleats | 129 | 2.4 (2.1-2.8)b | 185 | 3.6 (3.2-4.0)c | 174 | 3.3 (2.9-3.7)c | 75 | 2.9 (2.3-3.4)b |
| 12-studded removable cleats | 185 | 3.5 (3.1-3.9)d | 219 | 4.2 (3.8-4.6)d | 329 | 6.3 (5.8-6.7)e | 56 | 2.1 (1.7-2.7)d |
| Edge/blade-style cleats | 106 | 2.0 (1.7-2.4)b,f | 107 | 2.1 (1.7-2.4)b | 146 | 2.8 (2.4-3.2)b | 104 | 4.0 (3.4-4.6)c,g |
| Molded/hybrid cleats | 423 | 8.0 (7.7-8.3)d,f,h | 572 | 11.0 (10.7-11.3)b,e | 797 | 15.2 (14.7-15.6)c,g | 511 | 19.4 (19.0-19.7)c,i |
| Turf/elastomeric short rubber | 74 | 1.4 (1.1-1.7)f,h | 241 | 4.6 (4.2-5.1)i | 144 | 2.7 (2.4-3.1)g | 78 | 3.0 (2.4-3.5)g |
| Field conditions | ||||||||
| No precipitation/dry field | 777 | 14.7 (14.2-15.1)d,f | 1083 | 20.8 (20.4-21.1)b,e | 1395 | 26.6 (26.0-27.0)c,g | 726 | 27.6 (26.9-28.1)c,g |
| Rain/snow/sleet | 72 | 1.4 (1.1-1.7)d | 157 | 3.0 (2.6-3.4)b,e | 78 | 1.5 (1.2-1.8)d | 54 | 2.1 (1.6-2.6)c,d |
| No precipitation/wet field | 68 | 1.3 (1.0-1.6)d | 84 | 1.6 (1.3-2.0)d | 117 | 2.2 (1.9-2.6)e | 44 | 1.7 (1.3-2.2)d |
| Adverse conditions combined | 140 | 2.7 (2.3-3.0)d,f | 241 | 4.6 (4.2-5.1)g | 195 | 3.7 (3.3-4.1)e | 98 | 3.7 (3.2-4.3)e |
| Temperature | ||||||||
| Cold days (≤59°F) | 116 | 2.2 (1.9-2.6)b,d,h | 255 | 4.9 (4.4-5.3)e | 320 | 6.1 (5.7-6.5)i | 147 | 5.6 (5.0-6.2)c |
| Moderate days (60-79°F) | 532 | 10.1 (9.9-10.2)f,h | 560 | 10.7 (10.4-10.9)d,g | 742 | 14.1 (13.6-14.6)e,i | 354 | 13.5 (12.8-14.1)e,i |
| Hot days (≥80°F) | 269 | 5.1 (4.7-5.5)h | 509 | 9.7 (9.5-9.8)i | 528 | 10.1 (9.9-10.2)b,i | 323 | 12.3 (11.7-12.8)c,i |
| Turf age | ||||||||
| New | 91 | 1.7 (1.4-2.1)b,d | 136 | 2.6 (2.3-3.0)c | 168 | 3.2 (2.8-3.6)e | 96 | 3.7 (3.1-4.2)e |
| 1-3 y | 390 | 7.4 (7.0-7.7)d,h | 481 | 9.2 (9.0-9.4)e | 476 | 9.1 (8.8-9.3)i | 389 | 14.8 (14.1-15.4)i |
| 4-7 y | 379 | 7.2 (6.8-7.50f,h | 648 | 12.4 (12.0-12.8)i | 691 | 13.2 (12.7-13.6)i | 229 | 8.7 (8.2-9.1)g |
| ≥8 y | 57 | 1.1 (0.8-1.4)h | 59 | 1.1 (0.9-1.4)h | 255 | 4.9 (4.4-5.3)i | 110 | 4.2 (3.6-4.8)i |
aWilks λ cleat design (F 4,4646 = 15.570; P = .0001); field conditions (F 4,4646 = 6.184; P = .0001); temperature (F 2,4649 = 7.520; P = .0001); turf age (F 3,4649 = 21.621; P = .0001). IIR, injury incidence rate (calculated as [number of injuries/number of team games] × 10).
Statistically significant at b,cP < .05, d,eP < .01, f,gP < .001, h,iP < .0001.