Letter to the Editor regarding 'All joint moments significantly contribute to trunk angular acceleration'

摘要

At the outset let me congratulate the authors on their use of recent advancements in 3D measurements and biomechanical modeling to demonstrate the influence of all three lower limb moments on the trunk angular acceleration. Previous analysis by McKinnon and Winter (1993) using a "top-down" model of the HAT in the frontal plane showed that the trunk angular was a function of the gravitational moment, the hip ab/abd moment and the hip joint vertical and horizontal accelerations. This model recognized in these two joint accelerations the net contributions of the moments of the two distal joints. A similar top-down sagittal plane model of HAT balance was reported in Winter (1995). The significant contribution in this new paper is that it represents a much more difficult "bottom-up" approach and partitions the contributions of all joint moments and their reaction joint force coupling contributions to the HAT angular accelerations in both planes. Of particular interest is the contribution of the large plantarflexor ankle moment to the trunk's angular acceleration.