Walking with robot assistance: the influence of body weight support on the trunk and pelvis kinematics

Abstract

Purpose: The goal was to assess in healthy participants the three-dimensional kinematics of the pelvis and the trunk during robot-assisted treadmill walking (RATW) at 0%, 30% and 50% body weight support (BWS), compared with treadmill walking (TW). Methods: 18 healthy participants walked (2 kmph) on a treadmill with and without robot assistance (Lokomat; 60% guidance force; 0%, 30% and 50% BWS). After an acclimatisation period (four minutes), trunk and pelvis kinematics were registered in each condition (Polhemus Liberty™ [240 Hz]). The results were analysed using a repeated measures analysis of variance with Bonferroni correction, with the level of suspension as within-subject factor. Results: During RATW with BWS, there were significantly (1) smaller antero-posterior and lateral translations of the trunk and the pelvis; (2) smaller antero-posterior flexion and axial rotation of the trunk; (3) larger lateral flexion of the trunk; and (4) larger antero-posterior tilting of the pelvis compared with TW. Conclusions: There are significant differences in trunk and pelvis kinematics in healthy persons during TW with and without robot assistance. These data are relevant in gait rehabilitation, relating to normal balance regulation. Additional research is recommended to further assess the influence of robot assistance on human gait.

Implications for Rehabilitation

• The trunk and pelvis moves in a different way during walking with robot assistance.

• The data suggest that the change in movement is due to the robot device and the harness of the suspension system more than due to the level of suspension itself.

• Body weight support
• gait
• kinematics
• pelvis
• robot
• trunk

Acknowledgements

We are grateful to the VUB language centre (ITO) for proofreading the text in English. We would also like to thank the therapists of the rehabilitation centre for participation and assistance in the study.

Test location and ethical commission

All measurements were performed at the Rehabilitation Centre St. Ursula, Jessa Hospital, Herk-de-Stad, Belgium. The protocol was approved by the local ethics commission of the university (BUN B1432008499) and the rehabilitation centre (12.11/fys12.02).

Declaration of interest

We confirm that there are no conflicts of interest associated with this publication and there has been no financial support for this work that could have influenced its outcome.

All authors were fully involved in the study and preparation of the manuscript and the results of this study has not been and will not be submitted for publication elsewhere.