Classification accuracy of whole-body gestures can be improved by selecting gestures that have few conflicts (i.e., confusions or misclassifications). To identify such gestures, an understanding of the nuances of how users articulate whole-body gestures can help, especially when conflicts may be due to confusion among seemingly dissimilar gestures. To the best of our knowledge, such an understanding is currently missing in the literature. As a first step to enable this understanding, we designed a method that facilitates investigation of variations in how users move their body parts as they perform a motion. This method, which we call filterJoint, selects the key body parts that are actively moving during the performance of a motion. The paths along which these body parts move in space over time can then be analyzed to make inferences about how users articulate whole-body gestures. We present two case studies to show how the filterJoint method enables a deeper understanding of whole-body gesture articulation, and we highlight implications for the selection of whole-body gesture sets as a result of these insights.