Volunteer heading biteplate acceleration data*
| Ball speed | |||
|---|---|---|---|
| 6.4 m/s | 8.2 m/s | ||
| *n = 5 for each mean, comparing headgears to bare head (two tailed t test, df = 8, tcritical = 2.306). | |||
| Bare head | Mean | 5.4 g | 7.6 g |
| SD | 1.5 g | 1.6 g | |
| A | Mean | 6.8 g | 5.7 g |
| SD | 0.6 g | 1.8 g | |
| t stat | −2.013 | 1.699 | |
| p | 0.079 | 0.128 | |
| B | Mean | 5.1 g | 6.1 g |
| SD | 1.6 g | 1.1 g | |
| t stat | 0.244 | 1.644 | |
| p | 0.813 | 0.139 | |
| C | Mean | 5.5 g | 6.8 g |
| SD | 1.1 g | 1.2 g | |
| t stat | −0.154 | 0.862 | |
| p | 0.881 | 0.414 | |