Baseline characteristics of the two groups
| Lower extremity group | Other locations group | P value | |
| Sex, n (%) | |||
| Male | 954 (60.6) | 207 (63.1) | 0.391 |
| Female | 621 (39.4) | 121 (36.9) | |
| Body mass index, mean (SD) | 19.0 (3.0) | 18.7 (2.7) | 0.111 |
| Body height increase over the past year, mean cm (SD) | 4.8 (2.9) | 5.1 (2.8) | 0.059 |
| Practice time per week, mean h (SD) | 14.3 (7.4) | 15.0 (9.0) | 0.174 |
| Athletic experience, mean years (SD) | 4.4 (0.8) | 3.9 (2.4) | 0.002 |
| Injury mechanism, n (%) | |||
| Contact | 366 (23.2) | 54 (16.5) | <0.01 |
| Non-contact | 1209 (76.8) | 274 (83.5) | |
| History of visiting other medical centres, n (%) | |||
| Yes | 647 (41.1) | 140 (42.7) | 0.592 |
| No | 928 (58.9) | 188 (57.3) | |
| Competitions over the past year, n (%) | |||
| Regional tournament | 966 (61.3) | 222 (67.7) | 0.092 |
| Prefectural tournament | 450 (28.6) | 85 (25.9) | |
| National tournament | 148 (9.4) | 20 (6.1) | |
| World competition | 11 (0.7) | 1 (0.3) | |
| Future goals, n (%) | |||
| To discontinue sports | 1041 (66.1) | 204 (62.2) | <0.01 |
| To achieve a recreational level | 194 (12.3) | 27 (8.2) | |
| To become a professional athlete | 274 (17.4) | 88 (26.8) | |
| To become a coaching staff | 66 (4.2) | 9 (2.7) |