Center of gravity velocity estimation using lower limb joint power during walking

Abstract

This paper presents examination of a proposed method for center of gravity (COG) velocity estimation during walking using information obtained from lower limb motion measurements. Lower limb joints and muscles around these joints are used during walking. Gait velocity changes according to lower limb muscle activity. Some earlier reports of relevant studies have suggested that lower limb muscle weakness reduces the walking rate, which increases the probability of falling. Therefore, the relation between the COG velocity and lower limb motion during walking must be clarified. For this study, we constructed gait COG velocity models that represent the relation between the COG velocity and lower limb joint power for each gait phase. For this experiment, gait was measured using a 3D motion analysis system and floor reaction force gauges. We estimated the gait COG velocity models' parameters by applying Kalman filtering using measurement information. The results of analyses using gait COG velocity models indicate a quantitative relation between the COG velocity and the lower limb joint power during walking. Furthermore, results demonstrated that the lower limb joint power that influences the COG movement differs in each gait phase. This analytical method is anticipated for use in the evaluation of healthy feet and ill feet and for evaluating the balance of left and right feet.

Analysis of center of gravity velocity using estimated lower limb muscle forces during squatting

“…Thus, complex exercises require multiple models for each phase. For example, in a study that estimated walking speed using lower limb joint power, two models were developed for the stance phase because the joint power differed greatly between the single support phase and the double support phase (Saito et al, 2019). In future work, in order to apply the proposed model to different types of movement, we will consider human motion from the viewpoint of kinematics and kinetics to develop a model that is suitable for an arbitrary movement.…”

Center-of-gravity velocity estimation using lower limb muscle forces during walking

“…Several studies have reported that the joint moments and power in lower limbs have a strong relationship with walking speed (Olney et al, 1991;Olney et al, 1994;Winter, 2009). The authors previously proposed a walking model that uses the center-of-gravity (CoG) velocity and lower limb joint power during walking and demonstrated that the lower limb joint power that influences CoG movement differs in each gait phase (Saito et al, 2019). Joint motion is caused by muscles pulling on bones.…”