Table 2

Comparison of helmet minus head cast measurements in head injured and non-head injured children

Characteristic*Cases (n=22)Controls (n=73)Two tailed p value†
*See accompanying protocol for measurement definitions based on the actual orientation of the helmet on the head.
t test for means.
Helmet minus head cast measurement (mean (SD) in cm and ml)
    Circumference at rim4.3 (2.5)4.9 (2.4)0.30
    Anterior-posterior length1.0 (1.5)1.0 (2.2)0.94
    Width 1.7 (0.9) 1.1 (1.9) 0.05
    Length of anterior-posterior arc2.7 (2.0)3.1 (2.2)0.43
    Length of width arc2.4 (2.0)2.2 (2.7)0.83
    Depth (helmet rim to top)1.0 (1.1)0.7 (1.0)0.19
    Volume (helmet rim to top)518 (227)458 (282)0.36