Table 4

Absolute numbers of acute injuries, average monthly severity scores and incidence (number of injuries per 1000 hours of tennis)

TotalClayHard courtSand-fill artificial grassRed-sand-fill artificial grassMultiple surfaces
Total number of injuries80120515715517092
Hours played1 01 82225 31719 79915 96722 14915 458
Incidence density
Upper extremity2.02 (1.72 to 2.32)1.94 (1.44 to 2.44)1.77 (1.17 to 2.37)3.01 (2.11 to 3.91)* 1.90 (1.30 to 2.50)1.88 (1.18 to 2.58)
Back0.61 (0.41 to 0.81)0.75 (0.45 to 1.05)0.81 (0.41 to 1.21)0.81 (0.41 to 1.21)0.32 (0.12 to 0.52)* 0.39 (0.09 to 0.69)*
Lower extremity4.57 (4.17 to 4.97)4.78 (3.88 to 5.68)4.60 (3.70 to 5.50)5.20 (4.10 to 6.30)* 4.61 (3.71 to 5.51)4.08 (3.08 to 5.08)*
Total7.87 (7.32 to 8.41)8.10 (6.99 to 9.21)7.93 (6.69 to 9.17)9.71 (8.18 to 11.24)* 7.68 (6.52 to 8.83)5.95 (4.74 to 7.17)*
HR 10.98 (0.80 to 1.21)1.20 (0.97 to 1.48)0.95 (0.77 to  1.16)0.74 (0.57 to 0.94)*
  • Data are presented as mean values ​​with SD for severity, and by 95% CIs for the incidence.

  • *Indicates a significant difference compared with ’total' (p<0.05).

  • HR is calculated with respect to clay.