I am trying to use the IndAccPI plug-in with an OpenSim model to define how the ground reaction force vector should be split into 5 distinct force vectors on each foot. This would be according to the foot contact model described in Dorn et al., 2012 and included in the IndAccPI plug-in. However, the plug-in's analysis is giving force vectors that point in seemingly random directions and the agreement between the MODEL_TOTAL and the EXPERIMENTAL values of the ground reaction force are very different.
The model that I am using is a single leg model with a three segment foot. 5 points are assigned to the left foot and the left foot force is zero throughout. This method worked with the example data included with the plug-in - where I reduced the model to only a single leg and used the same technique. However, with my own model - a single leg model with a three segment foot - the plug-in seems to find incorrect results.
Any help would be greatly appreciated on this. Running a static optimization on my model solves with no problems, so I don't think there are inherent problems with the models capacity to solve.
Thanks
Joe