student research day - Case Western Reserve University School of ...

Christopher McCrum
Validation of the MicroScribe coordinate measurement system for knee kinematics
Christopher McCrum, Robb Colburnn, Dr. Antoine van den Bogert
Department of Biomedical Engineering
Cleveland Clinic Foundation Lerner Research Institute
In order to better understand the kinematics of the knee, a reliable, accurate, precise form of data collection is crucial. The
R2000 robot has the ability to manipulate knee kinematics throughout the range of motion of the knee in all planes. To
measure kinematics of the knee, the robot uses the technology known as a MicroScribe coordinate measurement machine
to define the place in space of the knee throughout the experiment. However, the data collected by the robot has not been
validated through experimentation, while in the past, measurement systems that have been validated, such as motion
capture with the Qualysis MacReflex system, has been used. Hence, the hypothesis of this experiment is that there is no
difference between the data collected by the robot and the data collected by motion capture system, throughout the range
of motion of the knee. In order to test this hypothesis, a protocol was implemented, where the robot was ordered to move
to positions defined by the MicroScribe, while this movement was being measured by the motion capture system. Such
data points included a range of -10 to +10mm medial translation, -30 to +20mm posterior translation, -13 to -5mm superior
translation, 0 to 10 degrees flexion, -10 to +10 degrees of valgus, -40 to +40 degrees of internal rotation, and several
combined movements, all measured as the movement of the tibia relative to the femur. Analysis showed that there was not
a significant difference between the root mean squares of each of the groups, and the correlations were greater than 0.97
in all planes of motion, indicating a strong relationship between experimental measurements. Thus, under these motion
conditions, there is strong evidence that the kinematic data collected by the R2000 robot with the MicroScribe collects
valid, reliable data.
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