The purpose of this study was to build on previous research, sometimes conflicting, to determine if “one joint more strongly accelerates the trunk.” They also looked at coupling between the sagittal plane joint moments and the frontal plane trunk accelerations. Using an instrumented treadmill and 3-D motion analysis, their model calculated joint moments at the ankle, knee, and hip, to determine the relative affect of each joint on the trunk. Caution must be taken when interpreting the results because the model was employed on only one subject, but they “checked” their findings with previous research for validation.