TRACKING EPIDERMAL MARKERS IN X-RAY RECONSTRUCTION OF MOVING MORPHOLOGY OF WALKING CHICKENS: PHASE 1

X-Ray Reconstruction of Moving Morphology (XROMM) is widely used to understand the kinematics of living organisms. As this methodology focuses on skeletal elements, it is useful for paleontologists wanting to understand the kinematics of extinct organisms which have left behind only skeletal remains. However, the current standard in XROMM is to surgically implant X-ray dense markers directly into bones and subsequently euthanize the subjects at the conclusion of a study. For long term or longitudinal studies, this is problematic due to the required euthanasia and inevitable loss from post-surgery complications, necessitating a larger initial sample population, which in turn, adds complications of space and housing requirements. Herein, we present a portion of a larger study demonstrating the use of external markers on an organism’s epidermis to track kinematics without a loss in accuracy. Three chicken subjects were trained to walk at a comfortable pace on an X-ray translucent treadmill, in which all three were separately recorded using XROMM at Stockton University. The subjects were immobilized in a plastic cone and CT-scanned to record the locations of the external markers in relation to the bones prior to their removal. The program XMALab was used to isolate and track these markers as recorded from XROMM over the span of several strides. A low margin of error was achieved through the tracking of these epidermal markers, which is below the threshold established in the field and necessary for continuation onto 3D modeling. The CT-scan data were used to segment the femora, pelvis, and tibiotarsi of each individual in the program Slicer, and each element was exported as a 3D model (STL). Future steps in this project include combining the digital point tracking and 3D bones in Maya to calculate the kinematics of the chickens and to conduct a validation experiment comparing external epidermal markers to implanted markers in a deceased chicken carcass to provide a comparison of total error.