Table 1.
Number of observed matches, player hours, heading events, and head impact incidents according to age and sex during an international youth football tournament in Norway
| Level | Boys | Girls | ||||||
|---|---|---|---|---|---|---|---|---|
| Matches (n) | Player hours | Headers (n) | Incidents (n) | Matches (n) | Player hours | Headers (n) | Incidents (n) | |
| U‐12 | 16 | 112 | 138 | 0 | 12 | 84 | 53 | 0 |
| U‐13 | 33 | 231 | 423 | 2 | 28 | 196 | 178 | 0 |
| U‐14 | 21 | 252 | 562 | 0 | 12 | 144 | 77 | 1 |
| U‐15 | 17 | 249 | 565 | 0 | 14 | 205 | 293 | 0 |
| U‐16 | 10 | 183 | 432 | 1 | 12 | 220 | 411 | 1 |
| U‐17 | 18 | 330 | 1079 | 3 | 12 | 220 | 495 | 0 |
| U‐18 | 6 | 132 | 405 | 0 | 14 | 308 | 536 | 1 |
| U‐20 | 12 | 264 | 855 | 4 | 10 | 220 | 534 | 2 |
| Senior* | 10 | 330 | 1127 | 9 | 10 | 330 | 886 | 6 |
*
Senior level was observed from TV video recordings from the Norwegian premier leagues (Toppserien and Eliteserien), and included for comparison.