Analytically derived three-dimensional reach volumes based on multijoint movements

The main objectives of this study were to quantify the range of reaching for the upper body with eight degrees of freedom (the trunk and shoulder, elbow, and wrist joints) and the lower body with six degrees of freedom (the hip, knee, and ankle joints). A sweeping algorithm that included trunk and foot motions was used to generate the analytical total reach volume of the human body for young men. Three types of reach volume--unconstrained arm reach, shoulder-restricted arm reach, and foot reach--were generated depending on the joint involved in reach activities. The robot kinematics methodology was employed to represent the human body as a multilink system, which was needed for calculating three-dimensional coordinates of the involved joints. The statistical test results showed that the total reach volume analytically generated in this study was nearly identical to that obtained from the direct human body measurements. Applications of this research include generating the human body's reach volume for the purpose of designing work spaces and products.