This paper was presented at the Twenty-first Annual National Conference of the Society of Aeronautical Weight Engineers at Seattle, Washington, May 14-17, 1962. One of the many problems associated with manned space vehicles confronting the weight control engineer is the predication of center of gravity location and mass moment of inertia about three axes of the human body.
In keeping with modern weight accounting methods, an airplane type IBM routine has been adapted for center of gravity and inertial calculations. It was obvious that a human body divided into several parts or segments would yield better results than using the body as one item. This division of the body yielded fourteen segments. The head and neck were left intact. The trunk or torso was separated from the extremities. The extremities were divided into three segments each such as the hand, lower arm and upper arm. Mass, center of gravity location and dimensional data for each segment were derived from existing reports and fed into the IBM routine as weight empty. It is worthwhile to mention the condition of the body when placed in the IBM routine was in an unclad or nude state. Clothing and equipment when decided on could be added as useful load items.
As a result of supporting a related study, the body was placed in IBM in seven positions. These seven positions were selected to give the center of gravity “box” of limits along the three axes. Body positions were accomplished by moving only the arms and legs. The head, neck and trunk remained in the same location from the reference planes for all seven positions.
Although being unable to experimentally test the moment of inertial data, center of gravity location test for several positions were conducted using subjects within the percentile range of the calculated subject. Tests were conducted by two methods. A simple two scale reaction was used first. The second test was conducted on a very excellent test stand designed to measure center of gravity locations along three axes.