RR of Australian footballers sustaining a HSI in the following week using relative running exposure variables and arbitrary cut-points and associated receiver operator characteristic curve values of predictive properties
| Running exposure variable and associated cut-point | RR (95% CI) | Sensitivity | Specificity | AUC |
|---|---|---|---|---|
| Acute:chronic workload for distance covered | ||||
| Above 10 km/hour | 0.55 | |||
| 0.5 | 1.1 (0.3 to 4.7) | 0.92 | 0.09 | |
| 0.75 | 1.3 (0.4 to 3.7) | 0.83 | 0.20 | |
| 1 | 1.1 (0.5 to 2.6) | 0.58 | 0.45 | |
| 1.25 | 1.2 (0.5 to 2.9) | 0.33 | 0.71 | |
| 1.5 | 1.6 (0.6 to 4.3) | 0.21 | 0.86 | |
| 1.75 | 1.8 (0.5 to 5.9) | 0.13 | 0.93 | |
| 2 | 0.8 (0.1 to 6.1) | 0.04 | 0.95 | |
| Above 24 km/hour | 0.52 | |||
| 0.5 | 2.2 (0.5 to 9.4) | 0.92 | 0.17 | |
| 0.75 | 0.9 (0.4 to 2.1) | 0.67 | 0.31 | |
| 1 | 1.4 (0.6 to 3.1) | 0.58 | 0.50 | |
| 1.25 | 1.3 (0.5 to 2.9) | 0.38 | 0.68 | |
| 1.5 | 1.1 (0.4 to 2.8) | 0.21 | 0.80 | |
| 1.75 | 0.9 (0.3 to 3.2) | 0.13 | 0.87 | |
| 2 | 0.5 (0.1 to 3.3) | 0.04 | 0.91 | |
| Relative week-to-week change in distance covered | ||||
| Above 10 km/hour | 0.61 | |||
| 0.5 | 1.0 (0.3 to 3.3) | 0.88 | 0.12 | |
| 0.75 | 1.9 (0.6 to 5.5) | 0.84 | 0.26 | |
| 1 | 1.7 (0.7 to 3.8) | 0.64 | 0.49 | |
| 1.25 | 2.6 (1.2 to 5.8) | 0.56 | 0.67 | |
| 1.5 | 2.2 (1.0 to 5.0) | 0.40 | 0.77 | |
| 1.75 | 1.9 (0.8 to 4.6) | 0.28 | 0.83 | |
| 2 | 2.6 (1.1 to 6.3) | 0.28 | 0.87 | |
| Above 24 km/hour | 0.62 | |||
| 0.5 | 3.2 (0.8 to 13.6) | 0.92 | 0.22 | |
| 0.75 | 1.8 (0.7 to 4.6) | 0.76 | 0.37 | |
| 1 | 1.6 (0.7 to 3.5) | 0.60 | 0.51 | |
| 1.25 | 2.1 (1.0 to 4.7) | 0.56 | 0.63 | |
| 1.5 | 2.5 (1.2 to 5.6) | 0.52 | 0.70 | |
| 1.75 | 2.9 (1.3 to 6.3) | 0.48 | 0.76 | |
| 2 | 3.6 (1.7 to 7.9) | 0.48 | 0.80 | |
| Distance covered above 24 km/hour as a percentage of distance covered above 10 km/hour | 0.63 | |||
| 2.5% | 6.3 (1.5 to 26.7) | 0.93 | 0.34 | |
| 5% | 2.1 (1.0 to 4.5) | 0.41 | 0.75 | |
| 7.5% | 0.9 (0.2 to 4.0) | 0.07 | 0.92 | |
| 10% | NA | 0.00 | 0.98 | |
Acute:chronic workload ratio is the ratio of distance covered in a week (acute workload) compared with the weekly average of the same variable over the preceding 4-week period (chronic workload). Note that the 4-week period over which the chronic workload is calculated is inclusive of the acute workload week. Relative week-to-week change in distance is the ratio of distance covered in a week compared with the previous week. A value >1 indicates an increase from one week to the next, whereas a value <1 indicates a decrease from one week to the next.
AUC, area under the curve; HSI, hamstring strain injury; RR, relative risk.