Table 1.
Total | Per Groups | Per History of Hamstring Injury | ||||
---|---|---|---|---|---|---|
Japan | France | Finland | No Previous Hamstring Injury |
History of Previous Hamstring Injury |
||
Number (n (%)) | 284 (100) | 110 (39) | 56 (20) | 118 (42) | 224 (79) | 60 (21) |
Anthropometrical parameters (mean (SD)) | ||||||
Age (years) | 21.4 (4.3) | 20.0 (1.0) c** | 18.2 (1.8) | 24.3 (5.3) a,b*** | 21.3 (4.1) | 22.1 (5.2) |
Height (cm) | 176.7 (7.2) | 172.7 (5.2) c*** | 177.0 (6.7) | 180.4 (7.0) a***,b** | 176.7 (7.2) | 177.0 (7.0) |
Mass (kg) | 71.3 (8.4) | 66.9 (5.3) | 68.1 (8.1) | 77.0 (7.6) a,b*** | 71.4 (8.5) | 71.2 (8.3) |
History of hamstring muscle injury | ||||||
Number of players (%) | 60 (21) | 16 (15) | 14 (25) | 30 (25) | 0 (0) | 60 (100) |
Sprint acceleration mechanical outputs (mean (SD)) | ||||||
Pmax (W·kg−1) | 16.8 (1.6) | 16.3 (1.4) c*** | 17.3 (1.8) | 16.9 (1.6) a** | 16.7 (1.6) | 17.1 (1.7) |
FH0 (N·kg−1) | 7.5 (0.6) | 7.4 (0.6) | 7.5 (0.6) | 7.5 (0.6) | 7.5 (0.6) | 7.5 (0.6) |
V0 (m·s−1) | 9.0 (0.5) | 8.8 (0.5) c*** | 9.3 (0.6) | 9.1 (0.4) a***,b** | 9.0 (0.5) d* | 9.1 (0.5) |
F-v profile | −0.83 (0.08) | −0.84 (0.09)c* | −0.81 (0.09) | −0.83 (0.07) | −0.84 (0.09) | −0.82 (0.08) |
New hamstring injury | ||||||
Number of players with new hamstring injury (n (%)) | 38 (13) | 6 (6) | 12 (21) | 20 (17) | 16 (7) | 22 (37) |
Number of new hamstring injury (n) | 47 | 8 | 16 | 23 | 19 | 19 |
Incidence of new hamstring injury (per 1000 h of football (95% CI)) | 0.4 (0.3 to 0.5) | 0.1 (0.0 to 0.2) | 0.8 (0.5 to 1.2) | 0.6 (0.4 to 0.9) | 0.2 (0.1 to 0.3) | 0.8 (0.4 to 1.2) |
a Finland differed from Japan and from France; b Finland differed from France; c Japan differed from France; d “No previous hamstring injury differed” from “History of previous hamstring injury”; * p < 0.05; ** p < 0.01; *** p < 0.001. 95% CI: 95% confidence interval. F-v profile corresponds to the slope of the F-v linear relationships. Among the 284 included players, a total of 241 injuries (95% leading to time loss in football) were reported during the season in 159 players (56%). The main injury diagnosis was ankle sprain (n = 52, 22%), followed by hamstring injury (n = 47; 20%); other injuries were lower limb non-muscle injuries except ankle sprain (26%), lower limb muscle injuries except hamstring injury (22%), and other injuries (10%). The incidence of hamstring injuries per 1000 h of football varied according the three groups (lower for Japan group) and between players with and without history of hamstring injury (higher in players with history of previous hamstring injury).