Baseline characteristics
| Characteristic | N | Descriptive |
|---|---|---|
| Age in years (mean, SD) | 821 | 16.8 (0.8) |
| Weight in kg (mean, SD) | 824 | 78.8 (12.3) |
| Height in m (mean, SD) | 822 | 1.78 (0.07) |
| Age started playing rugby in years (mean, SD) | 809 | 9.2 (2.6) |
| Playing position (number backs/number forwards) | 824 | 387/437 |
| Involved in provincial or national squads (y/n) | 816 | 147/669 |
| History of at least one previous injury due to rugby (y/n) | 816 | 552/264 |
| History of previous concussion due to rugby (y/n) | 815 | 212/603 |
| Regularly wearing shoulder pads (y/n) | 814 | 252/562 |
| Regularly wearing mouthguard (y/n) | 814 | 642/172 |
| Regularly wearing head guard (y/n) | 812 | 259/553 |
| Regularly undertaking weight training (y/n) | 813 | 688/125 |
| Upper body strength (1RM bench press in kg) (mean, SD) | 603 | 76.40 (18.30) |
| Lower body strength (1RM squat in kg) (mean, SD) | 551 | 107.28 (27.18) |
1RM, 1 repetition maximum; y/n=yes/no.