Neglected physical human-robot interaction may explain variable outcomes in gait neurorehabilitation research

Abstract

Device transparency, support force, and attachment are important for optimal body-weight support in gait neurorehabilitation.

Development of split-force-controlled body weight support (SF-BWS) robot for gait rehabilitation

“…The root mean square error (RMSE) between the reference and measured forces, the average θs between natural and 30% BWS walking, and the average were evaluated ( Table 2 ). While Plooij et al (2021) argued that a higher support point impedes the forward-leaning of the upper body to take a step, and the mechanical structure inhibits the pelvis motion, the proposed harness poses negligible influence.…”

“…Even though the point of contact between a human and a BWS robot drastically affects walking patterns, it has rarely been studied ( Plooij et al, 2021 ). Most BWS robots use a harness that shares points of pressure with the lumbar-thoracic harness and thigh straps ( Hidler et al, 2011 ; Kwak et al, 2017 ; Mignardot et al, 2017 ).…”

“…While conventional harnesses wrap around the upper torso and connect double shoulder points to a spreader bar, Van Thuc and Yamamoto (2016) designed an original lumbar-thoracic harness with four shoulder point connections to four PAMs. The trunk is stabilized if the attachment points are as high as those at the shoulder or trunk level ( Plooij et al, 2021 ). Meanwhile, a pelvic brace ( Aoyagi et al, 2007 ; Pietrusinski et al, 2010 ), pelvic belt ( Patton et al, 2008 ; Khan et al, 2018 ), and pelvic frame ( Luu et al, 2014 ) are selectively used to apply the desired force around the pelvis.…”

“…Meanwhile, a pelvic brace ( Aoyagi et al, 2007 ; Pietrusinski et al, 2010 ), pelvic belt ( Patton et al, 2008 ; Khan et al, 2018 ), and pelvic frame ( Luu et al, 2014 ) are selectively used to apply the desired force around the pelvis. Attachments on the sides of the pelvis are beneficial in that they do not impede the forward-leaning of the upper body to take a step, compared to assists at a higher position ( Plooij et al, 2021 ). However, Plooij et al (2021) argued that the mechanical structure inhibits pelvic rotations along the vertical axis.…”

“…Attachments on the sides of the pelvis are beneficial in that they do not impede the forward-leaning of the upper body to take a step, compared to assists at a higher position ( Plooij et al, 2021 ). However, Plooij et al (2021) argued that the mechanical structure inhibits pelvic rotations along the vertical axis. Responding to these suggestions, we aim to design a harness and attachments to intervene in the pelvic obliquity, but not to impede natural walking movement, introduced in Section “3.…”