Characterization of spatio-temporal parameters of human gait assisted by a robotic walker

Abstract

Investigations of the biomechanical parameters of robotic walker assisted gait are needed to allow modern rehabilitation strategies and to improve further technological developments. In this study, spatio-temporal gait parameters were assessed during normal and assisted ambulation with the Simbiosis walker model, a robotic walker with forearm supports. Six infra-red video cameras, integrated in a movement analysis system, were used for three-dimensional reconstruction of body segments and measurement of biomechanical variables during assisted ambulation. Results showed that walker-assisted gait was marked by an overall reduction of spatio-temporal parameters, especially gait speed, without modification in cadence-speed and stride length-speed relationships. Future work investigating such modality of assisted gait in clinical conditions are warranted and may contribute for a better understanding of user-device interaction forces and its impact over gait biomechanics.

Sensor fusion to control a robotic walker based on upper-limbs reaction forces and gait kinematics

“…The human linear velocity ( h v ) can be defined as the product between the gait cadence and the step length [14] and, based on this, the amplitude of the LDD signal is estimated. As found on the literature [15], the WFLC algorithm can be used to robustly estimate the frequency of the input signal, and feed this information to the FLC algorithm that can robustly estimate the amplitude.…”

“…The gait cadence can be defined as the rhythm of a person's walk, usually expressed in steps per minute [14]. The frequency of the LDD signal is estimated to yield the gait cadence, and the method used is shown in Fig.…”

Assessment of walker-assisted gait based on Principal Component Analysis and wireless inertial sensors

“…As a consequence, Swing duration is larger, double support (DS) is shorter, as well as step time duration (Step_t). This happens because the walker usage has a great influence on the speed of the user that influences the overall spatiotemporal parameters (Frizera et al, 2012;Liu et al, 2009;Youdas et al, 2006). In terms of joint excursions, hip, knee, ankle and hip excursions decrease as well as the range of motion of sacrum when the user is assisted.…”

“…In conventional walker-assisted rehabilitation, therapists evaluate motor function and patients' performance based on qualitative information and personal expertise about the movement patterns. Joint displacement and muscle force are also manually assessed, which makes the fi nal clinical decisions empirical and subjective (Frizera et al, 2012).…”

“…In addition, the majority of the studies (Alkjaer et al, 2006;Bateni and Maki, 2005;Youdas et al, 2005) focused on standard frames and rollators with handgrips and used optical motion capture systems. In the research of Alkjaer et al (2006), Bateni and Maki (2005), Youdas et al(2005) and Frizera et al(2012) one identified some differences on gait performance with and without these types of walkers: improved balance, improved stability, decrease in speed and step width, and increase of stance phase time. However, only Alkjaer et al (2006) presented a kinematic analysis of the lower limbs, concluding that a rollator with handgrips causes an increase in hip flexion due to trunk forward flexion and also a reduction in the range of motion of all lower limbs' joints.…”