Table 3

 Univariate analysis of risk factors for non-contact anterior cruciate ligament (ACL) injuries

Risk factorMatches playedNon-contact ACL injuriesNon-contact ACL rate per 1000 team gamesRelative risk95% CI
    Northern10133818.81.971.28 to 3.02
    First grade25817815.1Ref
    Reserve grade1054104.70.310.16 to 0.61
Cricket wicket area
    No20975112.21.010.66 to 1.55
Enclosed roof
    No33838212.11.020.44 to 2.36
Time of game
    Day26575911.10.750.48 to 1.18
Previous month’s evaporation
    High (>48 mm)18916316.7Ref
    Low1530196.20.370.22 to 0.63
Previous year’s rainfall
    High (>600 mm)20104010.0Ref
    Low14104214.91.500.97 to 2.32
Ground hardness
    Medium355912.70.950.35 to 2.59
    Soft335811.90.900.32 to 2.51
Rain during match
    None (dry ground)11443414.9Ref
    None (wet ground)65323.11.550.46 to 5.19
    Heavy rain36113.90.930.12 to 7.02
    Light rain98210.20.690.16 to 2.90
Primary grass type
    Kikuyu23121.70.970.13 to 7.39
    Rye1725349.90.440.27 to 0.71
    Rye/annual blue grass mix7001510.70.480.26 to 0.88
Stage of season
    Early (Feb–Apr)9964020.1Ref
    Late (May–Sept)2639489.10.450.30 to 0.69