Data collection on the DC-9

The picture depicts a typical locomotion trial on the DC-9 during parabolic flight. The treadmill is mounted to the floor of the aircraft with a rigid frame that is covered with protective foam. Spotters are placed at the fore and aft of the subject to ensure safety. Cassie Wilson, an Exercise Physiologist, is running on the T2 during data collection. Mark Leach, David Chesney, crewmember Jeff Williams, and John Yaniec serve as spotters while observing the experiment. Reflective markers were attached to Cassie's left side. Markers were placed on the upper and lower thigh, the upper and lower shank, and the heel and toe. Her body was modeled as three rigid, linked segments. This configuration allowed each segment to be represented as the vector connecting the proximal marker to the distal marker. Three-dimensional marker locations were found using the six-camera motion capture system with a sampling frequency of 60 Hz.