The deviation between the body height in the standard measurement position and the comfortable (physiological) body height is approximately 1-1.5% (according to Flügel et al. 1988). The body dimensions dependent upon the body height are then lower.
Dimensions relevant to safety, for example of escape routes, should however always consider the maximum possible values of human dimensions, with the addition of clearances for rapid movement processes.
Anthropometric standard positions are assumed by persons only for relatively brief durations, and rarely correspond to the more comfortable, i.e. physiological body postures. Such dimensions are therefore often lower in practice than those produced by the standard measurements that are dependent upon stretching of the spine (e.g. body height, eye height sitting and standing, shoulder height sitting and standing, elbow height sitting and standing, height sitting, arm reach).
The high P95 values are rarely attained in a comfortable posture, whereas the lower P5 values are certainly relevant to the design of physiological comfort ranges. The same applies to dimensions dependent upon stretching of the arms (arm length, arm reach) and stretching of the legs (leg reach) when the arms and legs cannot be fully extended in practice (e.g. at the driver's workstation).