Changes in seated height in microgravity

Many physiological factors, such as spinal elongation, bone atrophy, and muscle loss, occur when humans are exposed to a microgravity environment. These physiological changes can result in slight to drastic changes in body dimensions. Any drastic change in body dimensions is critical information for current and future space hardware designers. These changes can affect accommodation, safety, and performance of a crewmember while in space. This study measured the overall change in seated height and stature for crewmembers exposed to a microgravity environment. Seated height data were obtained from 29 crewmembers that included 8 International Space Station increment crew (2 females and 6 males) and 21 Shuttle crew (1 female and 20 males). The results indicate that all participating crewmembers experienced statistically significant change in seated height. The corresponding change, 6% from preflight, should be considered for vehicle designs as the necessary seated microgravity adjustment.