This morning at 0800, five members of Crew XV were given pedometers in order to monitor the number of steps they took throughout the day. This is the first stage of a mobility assessment trial been carried out by Dr. O'Keeffe, University of Limerick, Ireland, and throughout the day he asked the subjects at fixed intervals for their pedometer readings.

Pedometers use different approaches with regards to the electronics and mechanics of the units, but they all contain mechanisms that detect movement. The most common approach involves a small metal arm that moves up and down as you walk. Each time the "arm" moves, an electronic or manual counter is triggered and thus, a step is counted. (New pedometer systems that are entering the market use accelerometer sensors or GPS technology.) The objective of this research is to find out gross mobility patterns of planetary station crews, primarily to improve exercise training regimes to supplement possible reduced movement due to the limited space of the living environment. This reduced movement is intuitive in a smaller work / living environment but it is important to try and quantify it objectively with numbers as well as quantifying it subjectively (e.g. questionnaires). One consequence of reduced movement is the lack of subsequent "calf muscle pumping" action of the body's venous blood flow return system (similar to Deep Vein Thrombosis (DVT) on airplanes -- also known as Economy Class Syndrome).

Therefore with more accurate records of astronaut mobility patterns, medical staff will be able to design optimum exercise regimes (time of day and type of exercise) for space crews in order to maintain their peak physical health. Today's trial ran for 12hrs (0800-2000) and already the results are quiet interesting showing a large difference in mobility between different crew members at the end of the day (for example one subject took 5010 steps while another took 19464!). With this information you can multiply the above figures by average stride length (ask the subject to take 10 steps and measure the total distance and divide by 10) and calculate distance covered.

Any information collected with pedometers should not be taken as absolute (due to inherent limitations such as false triggering, etc.), however it does allow researchers to build up interesting pictures of mobility activity and therefore design mission plans / exercise regimes / habitat layout more efficiently.

Ongoing results of this trial will be presented over the next few days.