There are many instances where inertial properties of the human body or its segments are needed for analysis of human motion. Some of the most critical of these are the design of safety devices to protect a seated person during a vehicular collision, such as an automotive seat belt system or a pilot ejection system.  Since many studies have dealt with military combat situations, they have primarily dealt with young adult males.  However, a few studies have included adult females and individuals of other ages. - Automotive restraints, for instance, have been designed using this data under the assumption that a system able to restrain a 50% male could restrain the 95% female and all children. However, as automotive safety systems have become more complex than passive restraints, this assumption may no longer be adequate. Therefore, it is more critical than ever before to determine the inertial properties of children.