N | Univariate | Multivariate | Association with risk (↑\↓\=) | Best evidence synthesis | ||||
Low risk of bias | High risk of bias | Low risk of bias | High risk of bias | Presence of association | Level of evidence | |||
Risk factors | ||||||||
Chronological age | 3008 | 6 8 | 6 | ↑ 6 8 | Yes | Strong | ||
Sex | 190 | 25 | =25 | No | Limited | |||
Limb dominance | 1544 | 8 | 22 | =8 22 | No | Moderate | ||
Player stature | 1401 | 8 | =8 | No | Limited | |||
Player body mass/weight | 3008 | 6 8 | =6 8 | No | Strong | |||
BMI | 1607 | 6 | ↑ 6 | Yes | Limited | |||
Player height | 1607 | 6 | =6 | No | Limited | |||
Preseason period | 183 | 24 | ↑ 24 | Yes | Limited | |||
Shorter between-match recovery/congested playing schedule | 621 | 7 14 | =7 14 | No | Moderate | |||
Level of competition | 190 | 25 | =25 | No | Limited | |||
Playing position | 2300 | 8 | 10 | =8 10 | No | Conflicting | ||
Previous calf muscle strain injury | 3008 | 6 8 | ↑ 6 8 | Yes | Strong | |||
Previous adductor | 1401 | 8 | ↑ 8 | Yes | Limited | |||
Previous quadriceps | 1607 | 6 | ↑ 6 | Yes | Limited | |||
Previous knee | 173 | 23 | ↑ 23 | Yes | Limited | |||
Previous hamstring | 1401 | 8 | ↑ 8 | Yes | Limited | |||
Previous ‘lower leg, knee, thigh, ankle/foot and back’ | 155 | 13 | ↑ 13 | Yes | Limited | |||
Temperature | 1607 | 6 | =6 | No | Limited | |||
Evaporation in previous 7 days | 1607 | 6 | =6 | No | Limited | |||
Rainfall in previous 7 days | 1607 | 6 | =6 | No | Limited | |||
Rainfall on game day | 1607 | 6 | =6 | No | Limited | |||
Month of year | 1607 | 6 | =6 | No | Limited |
↑↑, association with future calf muscle strain; ↓, association with lower risk for future calf muscle strain; =, no association with future calf muscle strain; BMI, body mass index.