New advances in aircraft ejection seat technology have stimulated the development of an Advanced Dynamic Anthropomorphic Manikin (ADAM) that represents a male aviator population and possesses both static and dynamic human like characteristics. Systems Research Laboratories, Inc. (SRL), is presently under contract to the Armstrong Aerospace Medical Rescarch laboratories (AAMRL), Wright-Patterson Air Force Base, to develop and fabricate these manikins using detailed specifications for the anthropometry, center of mass locations, and mass moments of inertia of each body segment. The data used in these dcsigns havce been initially defined with respect to a standard set of anatomically based axis systems developed from measurements on human subjccts. These axis systems are based on anatomically defined points on the surface of each body segment. The physical design of ADAM, however, requires the data to be related to the mechanical structures of the segments. To accomplish this, mechanical axis systems have been defined for all body segments and transformations to the anatomical axis systems have been developed.

This paper summarizes the development of the mathematical procedure used to define and relate the mechanical axis systems with respect to the standard anatomical axis systems. The computer procedures used in performing the transformations of the anatomical data base in the mechanical axis systems are also described. Finally, the resulting mechanical axis systems developed for each of the ADAM sizes and the transformed data base are described.