Medial collateral ligament injuries of the knee in professional football
| MCL injuries, n (% of total no. of injuries) | 346 (4.3) |
| Reinjuries, n (%) | 37 (10.8) |
| Lay-off days, mean±SD | 23±23 |
| Index injury | 24±24 |
| Reinjury | 18±15 |
| Dominant leg injury | 24±22 |
| Non-dominant leg injury | 23±26 |
| Contact injury | 23±24 |
| Non-contact injury | 21±18 |
| Lay-off days, median (Q1–Q3) | 16 (8–31) |
| Index injury | 18 (8–32) |
| Reinjury | 13 (7–25) |
| Dominant leg injury | 19 (7–33) |
| Non-dominant leg injury | 15 (8–28) |
| Contact injury | 16 (8–29) |
| Non-contact injury | 16 (7–30) |
| Injury rate* (95% CI) | 0.33 (0.29 to 0.36) |
| Training injury rate | 0.14 (0.12 to 0.17) |
| Match injury rate | 1.31 (1.15 to 1.49) |
| Dominant leg injury rate | 0.20 (0.17 to 0.22) |
| Non-dominant leg injury rate | 0.13 (0.11 to 0.15) |
| Contact injury rate | 0.21 (0.18 to 0.24) |
| Non-contact injury rate | 0.10 (0.08 to 0.12) |
| Injury severity, n (%) | |
| Slight/minimal (0–3 days) | 32 (9.2) |
| Mild (4–7 days) | 54 (15.6) |
| Moderate (8–28 days) | 162 (46.8) |
| Severe (>28 days) | 98 (28.3) |
| Injury burden† (95% CI) | 7.6 (7.5 to 7.8) |
| Lay-off days/player/season, mean±SD | 1.8±9.6 |
*Injury rate expressed as number of injuries/1000 player-hours.
†Injury burden expressed as number of lay-off days/1000 player-hours (injury rate×mean lay-off).
MCL, medial collateral ligament; Q1, 25th percentile; Q3, 75th percentile.