Scaling with limited marker data

[Shunafrica White]

Hello,

I have some mocap data from stop jump landing trials. I have tried to scale the model in OpenSim but because I have limited marker data I am unable to scale the body segments (pelvis, shank, and thigh) in all three directions. Therefore, my scaling setup file only includes one marker pair that is assigned to the shank and thigh and two marker pairs that are assigned to the pelvis. Since the body segments cannot be defined in all three directions, the error between the experimental markers and the model markers is approximately 6 cm. It appears that while the data was collected joint center markers were not included with the marker set up which I understand that joint center markers are very helpful for scaling models. Is it possible to scale a model with good quality if you do not have joint center markers or cannot define body segments in all three directions? If there is a workaround/solution, can you please share?

Thank you!

Shunafrica