Seated reach capabilities for ergonomic design and evaluation with consideration of reach difficulties.

This paper aimed to identify the reach capabilities of 26 seated subjects considering the reach difficulty, orientation and other potential factors, and to find a method to model the minimum reach capability surfaces for fixed and adjustable seats. The reach capability radius was used as a measure of the reach capability and theoretically modeled. Based on the test data of seated reach, the distribution of the reach capability radius was analyzed. The strategy to select the minimum reach envelopes was constructed to accommodate a sufficient percentage of the target population for both fixed and adjustable seats. For adjustable seats, a method was developed to derive the reach capability data from the tested individual reach capability data by introducing seating position models to re-position the individual reach capability data. An application case was realized based on the cab packaging data of a mini-van, and the minimum reach envelopes of different difficulties were created and validated to accommodate 90% of the target population.