Functional Resistance Training With Gait Phase-Dependent Control Using a Robotic Walker: A Pilot Study

Strength training can contribute to the improvement of the lower limb muscles, which does not always transfer to the improvement of walking ability. It results from the lack of training for the muscles which are responsible to generate propulsion force during walking, such as plantar flexors and hip extensors. This study aims to examine and evaluate the effects of a gait phase-dependent control strategy on the kinematics and muscular activation of users and to assess whether it can contribute to enhancing the strength of lower limb muscles in a task-specific manner, especially for plantar flexors. Eight healthy, young, male subjects participated in our experiment. We recorded EMG data from the muscles of the lower and upper limbs during walking with a robotic walker under different conditions, as well as participants' lower limb joint angles, to investigate the effects of the gait phase-dependent control. We found that gait phase-dependent control can lead to a high activation level of plantar flexors and a high angular velocity during the pre-swing phase and that the activity in triceps brachii is lower than that with constant resistance. Furthermore, an experiment with 9 elderly subjects verified the training effects of gait phase-dependent control on the plantar flexors. Therefore, we conclude that the gait phase estimation method can train plantar flexors with high effectiveness and efficiency. The long-term effects of gait phase-dependent control on improving the walking ability of elderly people will be investigated in the future.