Application of an industrial robot in the sports domain: Simulating the ground contact phase of running

Abstract

Mechanical devices currently used to test sports equipment are limited to one or two degrees of freedom and cannot replicate complete human movements. The purpose of this study was to investigate the capabilities of a six-degrees-of-freedom industrial robot (iRobot) to replicate the ground contact phase of human running. The objectives were as follows: to quantify the repeatability of the iRobot system; to assess the ability of the system to replicate heelstrike running and forefoot running. High-speed video and force plate data were collected for a single-subject heelstrike running and forefoot running. The iRobot was programmed to replicate the two footstrikes and then to perform 500 cycles of each. System kinematics and ground contact forces were recorded every tenth cycle. The kinematic repeatability of the iRobot was extremely good (less than 2 mm mean standard deviation in all marker trajectories). The peak vertical ground reaction forces showed systemic trends specific to the footstrike; heelstrike 3 per cent decrease and forefoot 19 per cent increase over the 500 cycles. iRobot replication of the footstrikes met with some success, particularly for the forefoot running. The iRobot generated highly repeatable kinematics and demonstrated potential for applications within the footwear industry. A number of improvements to the system were identified which could further improve its ability to replicate human running.