Table 4. Risk factors associated with the incidence of musculoskeletal injuries.
Risk factor Injured Uninjured RR 95% CI p
Internal risk factors Age 21.9 2 3.3 22.0 2 4.3 0.92
Height (cm) 178.1 1 8.0 173.5 1 9.0 0.01
Weight (kg) 71.8 7 9.5 67.9 6 10.5 0.06
Tennis experience 15 (8–23) 15 (6–31) 0.79
ITF singles ranking > 742* 11 (11.5) 85 (88.5) 1.3 1.1 – 1.5 0.004
< 742 20 (30.8) 45 (69.2)
Gender Female 11 (15.5) 60 (84.5) 1.4 0.7 – 2.8 0.280
Male 20 (22.2) 70 (77.8)
Previous injury Absent 4 (3.6) 107 (96.4) 2.1 1.5 – 2.8 <0.001
Present 27 (54.0) 23 (46.0)
External risk factor
WBGT zone
Zone 4 8 (10.8) 66 (89.2) 1.2 1.0 – 1.4 0.02
Zone 5 23 (26.4) 64 (73.6)
Inciting event
Round of match
Qualifying 6 (11.5) 46 (88.5) 1.2 1.0 – 1.3 0.09
Main round 25 (22.9) 84 (77.1)
Match load Singles 7 (11.9) 52 (88.1) 1.2 1.0 – 1.3 0.09
Singles + doubles 24 (23.5) 78 (76.5)
RR: relative risk; CI: confidence interval; * includes 31 athletes with no ITF rank.