If training can reduce peak 3D valgus motions by magnitudes similar to the largest between- trial variations observed here for this variable, then reliable detection of these changes should be possible with a 2D method. We did not implement any form of training in this
study, nor did we instruct subjects to alter their valgus
patterns in any way during movement trials. Hence, the true
potential for the 2D method as a training evaluation tool
remains speculative. More work is necessary to determine
whether long term modifications to valgus motions are
possible, and, if so, by what magnitude they can realistically
be changed, before inclusion of 2D video as an evaluation can
seriously be considered