Balance Control and Energetics of Powered Exoskeleton-Assisted Sit-to-Stand Movement in Individuals With Paraplegic Spinal Cord Injury

Hui Fen Mao, Hsing Po Huang, Tung Wu Lu*, Ting Ming Wang, Cheng Hua Wu, Jwu-Sheng Hu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Objective: To quantify the effects of initial hip angle and angular hip velocity settings of a lower-limb wearable robotic exoskeleton (WRE) on the balance control and mechanical energy requirements in patients with paraplegic spinal cord injuries (SCIs) during WRE-assisted sit-to-stand (STS). Design: Observational, cross-sectional study. Setting: A university hospital gait laboratory with an 8-camera motion analysis system, 3 forceplates, a pair of instrumented crutches, and a WRE. Participants: Patients (N=12) with paraplegic SCI. Interventions: Not applicable. Main Outcome Measures: The inclination angle (IA) of the body's center of mass (COM) relative to the center of pressure (COP), and the rate of change of IA (RCIA) for balance control, and the mechanical energy and forward COM momentum before and after seat-off for energetics during WRE-assisted STS were compared between conditions with 2 initial hip angles (105° and 115°) and 3 initial hip angular velocities (800, 1000, 1200 rpm). Results: No interactions between the main factors (ie, initial hip angle vs angular velocity) were found for any of the calculated variables. Greater initial hip angle helped the patients with SCI move the body forward with increased COM momentum but reduced RCIA (P<.05). With increasing initial angular hip velocity, the IA and RCIA after seat-off (P<.05) increased linearly while total mechanical energy reduced linearly (P<.05). Conclusions: The current results suggest that a greater initial hip angle with smaller initial angular velocity may provide a favorable compromise between momentum transfer and balance of the body for people with SCI during WRE-assisted STS. The current data will be helpful for improving the design and clinical use of the WRE.

Original languageEnglish
Pages (from-to)1982-1990
Number of pages9
JournalArchives of Physical Medicine and Rehabilitation
Volume99
Issue number10
DOIs
StatePublished - 1 Oct 2018

Keywords

  • Exoskeleton device
  • Postural balance
  • Rehabilitation
  • Spinal cord injury

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