Percentage of all muscle injuries (%), incidences of all muscle injury per 1000 registered athletes and relative risks of injury with lower and upper limits of 95% of confidence interval (±95% CI) in male and female athletes for type, location, cause, severity, event groups and age categories during outdoor (WOC 2007, WOC 2009, WOC 2011, WOC 2013, OG 2012, EOC 2012 and EOC 2014) and indoor (WIC 2014, EIC 2009, EIC 2011, EIC 2013 and EIC 2015) championships.
| Outdoor championships | Indoor championships | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Male | Female | RR male vs female (±95% CI) | Male | Female | RR male vs female (±95% CI) | |||||
| % | Incidence±95% CI | % | Incidence±95% CI | % % | Incidence±95% CI | % % | Incidence±95% CI | |||
| Muscle injury type | ||||||||||
| Muscle tears | 63.6 | 36.8±4.6 | 67.2 | 22.1±3.9 | 1.66 (1.34 to 2.06)* small | 68.2 | 18.6±1.6 | 48.0 | 9.2±1.2 | 2.03 (1.04 to 3.95)* moderate |
| Muscle cramps | 36.4 | 21.1±3.5 | 32.8 | 10.8±2.7 | 1.95 (1.44 to 2.64)* moderate | 31.8 | 8.7±1.1 | 52.0 | 9.9±1.3 | 0.87 (0.41 to 1.85) small |
| Muscle injury location | ||||||||||
| Trunk | 6.6 | 3.8±1.8 | 12.0 | 4.0±1.7 | 0.96 (0.54 to 1.71) trivial | 6.8 | 1.9±0.6 | 4.0 | 0.8±0.4 | 2.44 (0.25 to 23.4) moderate |
| Upper extremity | 1.8 | 1.1±0.9 | 2.7 | 0.9±0.8 | 1.19 (0.38 to 3.74) trivial | 2.3 | 0.6±0.4 | 0.0 | 0.0±0.0 | – |
| Hip and groin | 10.3 | 6.0±2.2 | 6.0 | 2.0±1.2 | 3.01 (1.54 to 5.87)* large | 9.1 | 2.5±0.7 | 0.0 | 0.0±0.0 | – |
| Thigh | 54.6 | 31.6±5.0 | 49.2 | 16.2±3.3 | 1.95 (1.53 to 2.49)* moderate | 52.3 | 14.3±1.7 | 56.0 | 10.7±1.3 | 1.33 (0.69 to 2.58) small |
| Lower leg | 19.3 | 11.2±3.0 | 21.3 | 7.0±2.2 | 1.59 (1.08 to 2.34)* small | 20.5 | 5.6±1.1 | 24.0 | 4.6±0.9 | 1.22 (0.43 to 3.41) small |
| Others | 6.6 | 3.8±1.8 | 8.2 | 2.7±1.4 | 1.41 (0.75 to 2.68) small | 9.1 | 2.5±0.7 | 16.0 | 3.1±0.7 | 0.81 (0.20 to 3.24) small |
| Missing values | 0.8 | 0.5 | 0.0 | 0.0 | ||||||
| Muscle injury cause† | ||||||||||
| Overuse with gradual onset | 12.7 | 7.3±2.4 | 14.8 | 4.9±1.8 | 1.51 (0.94 to 2.41) small | 13.6 | 3.7±0.9 | 20.0 | 3.8±0.8 | 0.97 (0.30 to 3.18) trivial |
| Overuse with sudden onset | 40.4 | 23.4±4.3 | 41.5 | 13.7±3.1 | 1.71 (1.30 to 2.24)* small | 18.2 | 5.0±1.0 | 16.0 | 3.1±0.7 | 1.62 (0.49 to 5.38) small |
| Non-contact trauma | 24.0 | 13.9±3.3 | 21.9 | 7.2±2.2 | 1.93 (1.33 to 2.80)* moderate | 40.9 | 11.2±1.5 | 24.0 | 4.6±0.9 | 2.44 (0.97 to 6.12) moderate |
| Others | 21.6 | 12.5±3.2 | 21.3 | 7.0±2.2 | 1.78 (1.22 to 2.61)* small | 18.2 | 5.0±1.0 | 24.0 | 4.6±0.9 | 1.08 (0.38 to 3.11) trivial |
| Missing values | 1.3 | 0.5 | 9.1 | 16.0 | ||||||
| Muscle injury severity | ||||||||||
| No time loss | 33.0 | 19.1±3.9 | 40.4 | 13.3±3.0 | 1.43 (1.08 to 1.91)* small | 34.1 | 9.3±1.4 | 52.0 | 9.9±1.3 | 0.94 (0.45 to 1.96) trivial |
| Minimal (1–3 days) | 18.5 | 10.7±2.9 | 16.9 | 5.6±2.0 | 1.92 (1.26 to 2.92)* moderate | 9.1 | 2.5±0.7 | 8.0 | 1.5±0.5 | 1.62 (0.30 to 8.85) small |
| Mild (4–7 days) | 10.0 | 5.8±2.2 | 7.7 | 2.5±1.3 | 2.30 (1.25 to 4.25)* moderate | 13.6 | 3.7±0.9 | 12.0 | 2.3±0.6 | 1.62 (0.41 to 6.48) small |
| Moderate (8–28 days) | 24.0 | 13.9±3.3 | 21.9 | 7.2±2.2 | 1.93 (1.33 to 2.80)* moderate | 36.4 | 9.9±1.4 | 28.0 | 5.4±0.9 | 1.86 (0.77 to 4.50) small |
| Severe (>28 days) | 4.7 | 2.8±1.5 | 6.6 | 2.2±1.2 | 1.27 (0.61 to 2.64) small | 2.3 | 0.6±0.4 | 0.0 | 0.0±0.0 | |
| Missing values | 9.8 | 6.6 | 4.5 | 0.0 | ||||||
| Muscle injuries per event groups‡# | ||||||||||
| Sprints | 34.4 | 63.5±11.2 | 38.9 | 37.1±9.1 | 1.71 (1.26 to 2.32)* small | 38.6 | 34.8±16.2 | 20.0 | 12.1±10.6 | 2.86 (1.07 to 7.70)* moderate |
| Hurdles§ | 8.1 | 58.8±21.5 | 5.7 | 22.0±14.2 | 2.68 (1.28 to 5.63)* moderate | 18.2 | 55.6±37.4 | 24.0 | 44.8±35.0 | 1.24 (0.44 to 3.48) small |
| Middle distances | 5.1 | 30.6±14.3 | 7.0 | 23.3±13.6 | 1.32 (0.62 to 2.78) small | 2.3 | 4.3±8.4 | 4.0 | 5.7±11.2 | 0.75 (0.05 to 11.9) small |
| Long distances | 5.4 | 32.3±14.7 | 10.8 | 36.3±17.0 | 0.89 (0.46 to 1.71) small | 6.8 | 23.8±26.6 | 16.0 | 41.7±40.0 | 0.57 (0.13 to 2.49) moderate |
| Marathon | 12.0 | 103.6±30.4 | 8.9 | 44.3±22.7 | 2.34 (1.30 to 4.22)* moderate | |||||
| Race walks§ | 10.2 | 71.3±23.1 | 1.9 | 12.9±14.5 | 5.54 (1.72 to 17.8)* large | |||||
| Jumps | 13.2 | 56.7±16.3 | 9.6 | 20.9±10.5 | 2.71 (1.52 to 4.83)* moderate | 22.7 | 22.1±13.6 | 24.0 | 15.6±12.4 | 1.42 (0.52 to 3.87) small |
| Throws§ | 7.2 | 30.9±12.2 | 6.4 | 14.9±9.2 | 2.07 (1.00 to 4.30)* moderate | 2.3 | 7.9±15.5 | 0.0 | 0.0±0.0 | – |
| Combined events§ | 4.5 | 80.6±39.1 | 10.8 | 96.6±43.6 | 0.83 (0.43 to 1.62) small | 9.1 | 58.0±55.1 | 12.0 | 44.1±48.8 | 1.31 (0.31 to 5.65) small |
| Muscle injuries per age categories‡ | ||||||||||
| Age | ||||||||||
| <20 | 2.6 | 44.1±1.1 | 6.6 | 44.0±1.2 | 1.00 (0.44 to 2.28) trivial | 2.3 | 12.5±0.4 | 0.0 | 0.0±0.0 | – |
| 20–22 (Under 23) | 15.0 | 52.2±2.7 | 13.1 | 27.7±1.7 | 1.89 (1.18 to 3.02)* small | 20.5 | 23.9±1.1 | 16.0 | 13.3±0.7 | 1.80 (0.56 to 5.77) small |
| 23–25 | 22.4 | 55.2±3.2 | 19.7 | 29.3±2.1 | 1.88 (1.28 to 2.76)* small | 18.2 | 15.6±1.0 | 36.0 | 23.4±1.1 | 0.66 (0.26 to 1.71) moderate |
| 26–29 | 26.4 | 65.3±3.5 | 23.5 | 34.0±2.3 | 1.92 (1.35 to 2.73)* moderate | 31.8 | 31.4±1.3 | 32.0 | 21.8±1.0 | 1.44 (0.61 to 3.39) small |
| 30–34 | 16.6 | 73.9±2.8 | 14.8 | 37.1±1.8 | 1.99 (1.28 to 3.09)* moderate | 18.2 | 46.2±1.0 | 8.0 | 13.5±0.5 | 3.42 (0.74 to 15.9) large |
| ≥35 | 4.2 | 78.0±1.4 | 5.5 | 52.4±1.1 | 1.49 (0.69 to 3.20) small | 2.3 | 55.6±0.4 | 0.0 | 0.0±0.0 | – |
| Missing values | 0.8 | 2.7 | 6.8 | 8.0 | ||||||
| Outdoor and indoor championships | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Male | Female | RR male vs female (±95% CI) | ||||||||
| % | Incidence±95% CI | % | Incidence±95% CI | |||||||
| Muscle injury type | ||||||||||
| Muscle tears | 64.1 | 33.2±4.8 | 64.9 | 19.7±4.1 | 1.69 (1.38-2.07)* small | |||||
| Muscle cramps | 35.9 | 18.6±3.6 | 35.1 | 10.6±3.0 | 1.75 (1.33-2.31)* small | |||||
| Muscle injury location | ||||||||||
| Trunk | 6.6 | 3.4±1.9 | 11.1 | 3.4±1.7 | 1.02 (0.59-1.78) trivial | |||||
| Upper extremity | 1.9 | 1.0±1.0 | 2.4 | 0.7±0.8 | 1.34 (0.44-4.11) small | |||||
| Hip and groin | 10.2 | 5.3±2.3 | 5.3 | 1.6±1.2 | 3.29 (1.70-6.37)* large | |||||
| Thigh | 54.4 | 28.2±5.2 | 50.0 | 15.2±3.6 | 1.86 (1.48-2.34)* small | |||||
| Lower leg | 19.4 | 10.1±3.2 | 21.6 | 6.6±2.4 | 1.53 (1.07-2.20)* small | |||||
| Others | 6.9 | 3.6±1.9 | 9.1 | 2.8±1.5 | 1.28 (0.72-2.29) small | |||||
| Missing values | 0.7 | 0.5 | ||||||||
| Muscle injury cause£ | ||||||||||
| Overuse with gradual onset | 12.8 | 6.6±2.6 | 15.4 | 4.7±2.0 | 1.42 (0.92-2.20) small | |||||
| Overuse with sudden onset | 38.1 | 19.7±4.4 | 38.5 | 11.7±3.1 | 1.69 (1.30-2.21)* small | |||||
| Non-contact trauma | 25.8 | 13.4±3.6 | 22.1 | 6.7±2.4 | 1.99 (1.41-2.81)* moderate | |||||
| Others | 21.3 | 11.0±3.3 | 21.6 | 6.6±2.4 | 1.68 (1.18-2.40)* small | |||||
| Missing values | 2.1 | 2.4 | ||||||||
| Muscle injury severity | ||||||||||
| No time-loss | 33.1 | 17.2±4.1 | 41.8 | 12.7±3.3 | 1.35 (1.04-1.77)* small | |||||
| Minimal (1–3 days) | 17.5 | 9.1±3.0 | 15.9 | 4.8±2.0 | 1.89 (1.25-2.84)* small | |||||
| Mild (4-7 days) | 10.4 | 5.4±2.3 | 8.2 | 2.5±1.5 | 2.18 (1.25-3.81)* moderate | |||||
| Moderate (8–28 days) | 25.3 | 13.1±3.6 | 22.6 | 6.9±2.4 | 1.92 (1.36-2.70)* moderate | |||||
| Severe (>28 days) | 4.5 | 2.3±1.5 | 5.8 | 1.7±1.2 | 1.33 (0.65-2.74) small | |||||
| Missing values | 9.2 | 5.8 | ||||||||
| Muscle injuries per event groups1# | ||||||||||
| Sprints | 34.9 | 57.4±9.5 | 36.3 | 32.1±7.6 | 1.79 (1.34-2.39)* small | |||||
| Hurdles2 | 9.3 | 58.0±18.7 | 8.2 | 27.6±13.8 | 2.11 (1.16-3.81)* moderate | |||||
| Middle distances | 4.8 | 22.8±10.4 | 6.6 | 18.5±10.4 | 1.23 (0.60-2.54) small | |||||
| Long distances | 5.6 | 30.7±12.9 | 11.5 | 37.2±15.6 | 0.83 (0.46-1.50) small | |||||
| Marathon | 10.6 | 103.6±30.4 | 7.7 | 44.3±22.7 | 2.34 (1.30-4.22)* moderate | |||||
| Race walks2 | 9.0 | 71.3±23.1 | 1.6 | 12.9±14.5 | 5.54 (1.72-17.8)* large | |||||
| Jumps | 14.3 | 44.0±11.5 | 11.5 | 19.0±8.1 | 2.31 (1.40-3.80)* moderate | |||||
| Throws2 | 6.6 | 27.7±10.7 | 5.5 | 13.3±8.2 | 2.09 (1.01-4.32)* moderate | |||||
| Combined events2 | 5.0 | 74.5±32.2 | 11.0 | 82.0±34.4 | 0.91 (0.50-1.66) trivial | |||||
| Muscle injuries per age categories1 | ||||||||||
| Age | ||||||||||
| <20 | 2.6 | 35.8±1.2 | 5.8 | 33.6±1.2 | 1.07 (0.48-2.38) trivial | |||||
| 20–22 (Under 23) | 15.6 | 45.0±2.8 | 13.5 | 24.0±1.9 | 1.88 (1.21-2.90)* small | |||||
| 23–25 | 22.0 | 45.3±3.4 | 21.6 | 27.9±2.4 | 1.62 (1.14-2.30)* small | |||||
| 26–29 | 27.0 | 57.7±3.7 | 24.5 | 31.3±2.5 | 1.85 (1.34-2.55)* small | |||||
| 30–34 | 16.8 | 69.3±3.0 | 13.9 | 33.1±1.9 | 2.09 (1.37-3.19)* moderate | |||||
| ≥35 | 4.0 | 76.2±1.5 | 4.8 | 47.8±1.1 | 1.59 (0.75-3.40) small | |||||
| Missing values | 1.4 | 3.4 | ||||||||
Regarding event groups, the muscle injury incidences differed significantly between events for male and female athletes for outdoor, indoor and total championships (p<0.001). There were significant differences in the distribution of muscle injuries between male and female for outdoor and total championships (p<0.05), but not for indoors. There were differences in the distribution of muscle injuries between outdoor and indoor championships for female athletes (p<0.05; #).
Regarding age categories, muscle injury incidence increased significantly with age for male athletes for total championships (p<0.05).
*Significant relative risk between male and female athletes (p<0.05).
†Significant difference in the distribution between outdoor and indoor championships for male athletes (p<0.05).
‡Data from OG 2012 were excluded since information on age of registered athletes was not available.
§Disciplines differ for male and female athletes: hurdles: 110 m hurdles vs 100 m hurdles; race walks: 20 and 50 km vs 20 km only; throws: the weights of tools are different; and combined events: 10 vs 7 events; for male and female athletes, respectively.