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Hello everyone,
I'm Vivek and I have some questions regarding marker placement for the Point Cluster Technique (PCT).
I am currently running some simulations where I’m applying the PCT to the thigh segment. I’m struggling with implementing the right marker placement in my code. The original PCT paper [“A point cluster method for in vivo motion analysis: applied to a study of knee kinematics” by Andriacchi et.al.] talks about the PCT method being based on a cluster of points uniformly distributed on the limb segment.
I’m struggling to understand what “uniform” implies. In my quest of seeking an answer to this question, I came across a few papers with their methods section in the paper described placing 11 markers on the thigh segment in accordance with the PCT convention. I assumed that this was a reference to the “uniform” marker placement criteria.
I’ve been trying to make sense of the “uniform” criteria and I have the following questions:
1) Does uniform imply dividing the surface area of the lateral aspect of the thigh into N equal areas where N is the number of markers? And then placing these markers at the centroid of these areas?
2) Does uniform imply dividing the surface area of the lateral aspect of the thigh into N equal areas where N is the number of markers and placing these N markers inside these N areas randomly such they are well separated?
3) Does uniform just imply placing markers randomly on the entirety of the lateral aspect of the thigh such they are well separated?
4) Does uniform imply a very specific geometric arrangement of the markers? And if yes, is it on the lateral aspect of the thigh? And what is the description of this specific arrangement?
5) How does the uniform marker placement described in the papers also ensure no rotational symmetry in the marker cluster?
Kind Regards and Thank you,
Vivek
I'm Vivek and I have some questions regarding marker placement for the Point Cluster Technique (PCT).
I am currently running some simulations where I’m applying the PCT to the thigh segment. I’m struggling with implementing the right marker placement in my code. The original PCT paper [“A point cluster method for in vivo motion analysis: applied to a study of knee kinematics” by Andriacchi et.al.] talks about the PCT method being based on a cluster of points uniformly distributed on the limb segment.
I’m struggling to understand what “uniform” implies. In my quest of seeking an answer to this question, I came across a few papers with their methods section in the paper described placing 11 markers on the thigh segment in accordance with the PCT convention. I assumed that this was a reference to the “uniform” marker placement criteria.
I’ve been trying to make sense of the “uniform” criteria and I have the following questions:
1) Does uniform imply dividing the surface area of the lateral aspect of the thigh into N equal areas where N is the number of markers? And then placing these markers at the centroid of these areas?
2) Does uniform imply dividing the surface area of the lateral aspect of the thigh into N equal areas where N is the number of markers and placing these N markers inside these N areas randomly such they are well separated?
3) Does uniform just imply placing markers randomly on the entirety of the lateral aspect of the thigh such they are well separated?
4) Does uniform imply a very specific geometric arrangement of the markers? And if yes, is it on the lateral aspect of the thigh? And what is the description of this specific arrangement?
5) How does the uniform marker placement described in the papers also ensure no rotational symmetry in the marker cluster?
Kind Regards and Thank you,
Vivek