Dynamic considerations of heel-strike impact in human gait

Based on the impulsive-dynamics formulation, this article presents the analysis of different strategies to regulate the energy dissipation at the heel-strike event in the context of human locomotion. For this purpose, a seven-link 2D human-like multibody model based on anthropometric data is used. The model captures the most relevant dynamic and energetic aspects of the heel-strike event in the sagittal plane. The pre-impact mechanical state of the system, around which the analysis of the heel impact contribution to energy dissipation is performed, is defined based on published data. In the context of the proposed impulsive-dynamics framework, different realistic strategies that the subject can apply to modify the impact dynamics are proposed and analyzed, namely, the trailing ankle push-off, the torso configuration and the degree of joint blocking in the colliding leg. Detailed numerical analysis and discussions are presented to quantify the effects of the mentioned strategies