Higgins Michael, Halstead P David, Snyder-Mackler Lynn, Barlow David
Towson University, Towson, MD 21252, USA.
J Athl Train. 2007 Jan-Mar;42(1):5-10.
Instrumented helmets have been used to estimate impact acceleration imparted to the head during helmet impacts. These instrumented helmets may not accurately measure the actual amount of acceleration experienced by the head due to factors such as helmet-to-head fit.
To determine if an accelerometer attached to a mouthpiece (MP) provides a more accurate representation of headform center of gravity (HFCOG) acceleration during impact than does an accelerometer attached to a helmet fitted on the headform.
Single-factor research design in which the independent variable was accelerometer position (HFCOG, helmet, MP) and the dependent variables were g and Severity Index (SI).
Independent impact research laboratory.
INTERVENTION(S): The helmeted headform was dropped (n = 168) using a National Operating Committee on Standards for Athletic Equipment (NOCSAE) drop system from the standard heights and impact sites according to NOCSAE test standards. Peak g and SI were measured for each accelerometer position during impact.
Upon impact, the peak g and SI were recorded for each accelerometer location.
Strong relationships were noted for HFCOG and MP measures, and significant differences were seen between HFCOG and helmet g measures and HFCOG and helmet SI measures. No statistically significant differences were noted between HFCOG and MP g and SI measures. Regression analyses showed a significant relationship between HFCOG and MP measures but not between HFCOG and helmet measures.
Upon impact, MP acceleration (g) and SI measurements were closely related to and more accurate in measuring HFCOG g and SI than helmet measurements. The MP accelerometer is a valid method for measuring head acceleration.
仪器化头盔已被用于估计头盔撞击时传递到头部的撞击加速度。由于头盔与头部的贴合度等因素，这些仪器化头盔可能无法准确测量头部实际经历的加速度。
确定连接到咬嘴（MP）的加速度计在撞击过程中是否比连接到安装在头模上的头盔的加速度计能更准确地反映头型重心（HFCOG）加速度。
单因素研究设计，其中自变量为加速度计位置（HFCOG、头盔、MP），因变量为重力加速度（g）和严重程度指数（SI）。
独立撞击研究实验室。
使用美国国家运动器材标准操作委员会（NOCSAE）的下落系统，按照NOCSAE测试标准，将佩戴头盔的头模从标准高度和撞击部位落下（n = 168）。在撞击过程中，测量每个加速度计位置的峰值g和SI。
撞击时，记录每个加速度计位置的峰值g和SI。
HFCOG和MP测量值之间存在强相关性，HFCOG与头盔g测量值以及HFCOG与头盔SI测量值之间存在显著差异。HFCOG与MP的g和SI测量值之间未发现统计学上的显著差异。回归分析表明HFCOG与MP测量值之间存在显著关系，但HFCOG与头盔测量值之间不存在显著关系。
撞击时，MP加速度（g）和SI测量值与HFCOG的g和SI测量值密切相关，且在测量HFCOG的g和SI方面比头盔测量更准确。MP加速度计是测量头部加速度的有效方法。
