Table 1.
Demographic Summaries of Braced and Control Groups by Individual Participant and by Cluster
| Variable | Individually | Per Cluster1 | |||
|---|---|---|---|---|---|
| Controls N = 1088 |
Braced N = 993 |
Controls N = 29 |
Braced N = 21 |
P-value2 | |
| Gender | |||||
| Male N (%) | 1086 (99.8) | 991 (99.8) | 99.8 ± 0.6 | 99.8 ± 0.8 | 0.731 |
| Age (yrs) (mean ± SD) | 16.1 ± 1.1 | 16.2 ± 1.1 | 16.2 ± 0.3 | 16.2 ± 0.2 | 0.914 |
| BMI (kg/m2) (mean ± SD) | 24.5 ± 4.4 | 24.8 ± 4.6 | 24.5 ± 1.2 | 24.8 ± 1.0 | 0.384 |
| Grade | |||||
| Freshman N (%) | 217 (19.9) | 180 (18.1) | 18.3 ± 13.1 | 20.0 ± 15.2 | 0.674 |
| Sophomore | 339 (31.2) | 289 (29.1) | 31.4 ± 9.7 | 28.2 ± 12.0 | |
| Junior | 264 (24.3) | 258 (26.0) | 24.6 ± 8.1 | 24.9 ± 10.3 | |
| Senior | 268 (24.6) | 266 (26.8) | 25.7 ± 9.2 | 26.9 ± 6.6 | |
| Level of Competition | |||||
| Freshman N (%) | 202 (18.6) | 164 (16.5) | 16.0 ± 13.1 | 17.1 ± 13.7 | 0.866 |
| Sub-Varsity | 325 (29.9) | 295 (29.7) | 30.0 ± 10.8 | 30.1 ± 11.1 | |
| Varsity | 561 (51.6) | 534 (53.8) | 54.1 ± 11.5 | 52.8 ± 9.1 | |
| Offensive Position | |||||
| Back N (%) | 346 (34.2) | 347 (37.6) | 32.9 ± 8.4 | 35.9 ± 9.4 | 0.240 |
| End | 303 (30.0) | 259 (28.1) | 27.4 ± 7.0 | 24.8 ± 8.1 | |
| Line | 362 (35.8) | 316 (34.3) | 33.3 ± 7.6 | 33.1 ± 8.3 | |
| Defensive Position | |||||
| Back N (%) | 335 (32.6) | 328 (35.6) | 31.3 ± 9.1 | 33.0 ± 8.8 | 0.298 |
| Line | 404 (39.3) | 344 (37.4) | 38.0 ± 8.8 | 34.2 ± 9.0 | |
| Linebacker | 290 (28.2) | 249 (27.0) | 26.4 ± 7.2 | 26.0 ± 10.2 | |
| Shoe Height | |||||
| Low top N (%) | 378 (34.7) | 337 (33.9) | 35.7 ± 15.4 | 34.3 ± 15.5 | 0.757 |
| Mid top | 710 (65.3) | 656 (66.1) | 64.3 ± 15.4 | 65.7 ± 15.5 | |
| Shoe Cleat | |||||
| Detachable N (%) | 787 (72.3) | 736 (74.1) | 72.2 ± 9.9 | 72.1 ± 19.8 | 0.992 |
| Molded | 301 (27.7) | 257 (25.9) | 27.8 ± 9.9 | 27.9 ± 19.8 | |
| Previous Ankle Injury | |||||
| Yes N (%) | 113 (10.4) | 120 (12.1) | 10.4 ± 5.3 | 12.2 ± 7.6 | 0.377 |
| Leg Dominance | |||||
| Right N (%) | 1007 (92.6) | 913 (91.9) | 92.2 ± 5.2 | 92.0 ± 4.3 | 0.867 |
| Previous Use of Ankle Tape | |||||
| Yes N (%) | 184 (16.9) | 207 (20.8) | 17.0 ± 10.1 | 21.2 ± 12.0 | 0.203 |
| Previous Use of Ankle Braces | |||||
| Yes N (%) | 164 (15.1) | 221 (22.3) | 16.7 ± 10.8 | 20.4 ± 12.2 | 0.272 |
| FAAM Scale (median, range) | |||||
| Left | 32 (6 – 32) | 32 (6 – 32) | 31.0 ± 0.4 | 30.1 ± 1.8 | 0.041 |
| Right | 32 (2 – 32) | 32 (2 – 32) | 30.9 ± 0.5 | 30.3 ± 1.8 | 0.162 |
| Exposures Type (mean ± SD) | |||||
| Competition | 9.4 ± 3.4 | 10.0 ± 3.7 | 351 ± 184 | 474 ± 195 | 0.029 |
| Non-competition | 50.5 ± 11.7 | 50.7 ± 50.7 | 1896 ± 996 | 2396 ± 1008 | 0.089 |
| Exposure Surface (mean ± SD) | |||||
| Grass | 58.3 ± 13.4 | 56.9 ± 16.6 | 2187 ± 1100 | 2689 ± 1180 | 0.134 |
| Synthetic | 1.6 ± 2.7 | 3.8 ± 10.7 | 59 ± 131 | 181 ± 537 | 0.320 |
1
reported as mean average percentage (categorical) or average value (continuous) within each cluster
2
t-test p-value for comparison of cluster averages between groups