The Lokomat® Robotic in mobility-dependent adult patients with subacute stroke: cardiovascular exercise and transition to body-weight supported treadmill training

Author: Nicole Prideaux

Prideaux, Nicole, 2020 The Lokomat® Robotic in mobility-dependent adult patients with subacute stroke: cardiovascular exercise and transition to body-weight supported treadmill training, Flinders University, College of Nursing and Health Sciences

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Abstract

Stroke precedes low cardiovascular (CV) fitness, prompting national guidelines (Stroke Foundation, 2017) to recommend that subacute stroke rehabilitation include a minimum of 30 minutes of moderate intensity CV exercise, measured as 40-60% maximal oxygen consumption (VO2max), 3-6 Metabolic Equivalent of Task (MET), or 3-4 on the category ratio (CR-10) BORG scale (American College of Sports Medicine, 2014). Suboptimal levels of CV intensity are continually reported on the Lokomat® (Lefeber, Swinnen, & Kerckhofs, 2016) however, the Augmented Performance Feedback (APF) activities, which may assist in increasing CV workload (Koenig et al., 2011), have not been studied. Conversely, Body-Weight Supported Treadmill Training (BWSTT) has demonstrated efficacy for CV training in subacute stroke (Mackay-Lyons, McDonald, Matheson, Eskes, & Klus, 2013). Nonetheless, parameters to guide clinical decision-making regarding transition from the Lokomat® to BWSTT in stroke are unknown. As such, for mobility-dependent patients with subacute stroke, the primary aims of the current research were: (1) to determine if sustained moderate intensity CV exercise could be achieved using the APF activities of the Lokomat®; and (2) to explore the development of an algorithm and propose a clinical decision-making tool guiding transition from the Lokomat® to BWSTT in stroke.

Two observational studies were completed using 10 adult subacute rehabilitation inpatients with stroke. The first study assessed the CV workload achieved during three APF activities (Faster, Graph, Gabarello 2). CV workload was measured objectively by oxygen consumption (VO2) and MET, and subjectively by the BORG rate of perceived exertion (RPE) CR-10 scale for both breathing and affected-leg effort. Participants also rated their motivation and enjoyment, and Lokomat® settings were recorded. In the second study, an algorithm and clinical decision-making tool were proposed based on comparison of outcomes between participants clinically judged as ready versus not-ready for BWSTT. Outcomes measured for comparison included the: Functional Ambulation Category (FAC) score; assistance required for sit to stand, standing balance and evenness of weight-bearing; Lokomat® settings; degree of active affected-leg movement in standing; physiological gait pattern and assistance required in a BWSTT trial.

In all three Lokomat® APF activities, a moderate intensity of CV exercise was achieved, demonstrated objectively by a mean (SD) VO2 of 8.0 (3.8) ml/kg/min (estimated to 52% VO2max), and a mean (SD) MET of 3.1 (1.3). This was supported by mean BORG scores between 3 and 5. VO2 and MET were not affected by which APF activity was completed (p=0.110 and 0.240), with VO2, MET and BORG results maintained over 15 minutes. Lokomat® body-weight support (BWS) and guidance force (GF) significantly progressed (p<0.05) between study sessions as per clinical practice without significant changes in VO2 or MET over the six study sessions (p=0.380 and 0.527). Motivation scores were consistent for all APF activities and within and between all study sessions, however enjoyment was greater for the Graph APF activity (p<0.001).

Comparison between the four participants clinically judged as ready for BWSTT and the six participants clinically judged not-ready for BWSTT revealed that BWSTT ready participants had: a) a FAC of 1; b) independence in sit to stand and standing balance with even weight-bearing; c) Lokomat® settings of BWS <30%, GF <30-35%, and speed >2.0kph; d) more than 45 degrees of standing active hip and knee flexion; e) no significant issues with their physiological stepping pattern in BWSTT that could not otherwise be managed with verbal or physical facilitation from only one person. An algorithm and proposed clinical decision-making tool were developed guiding the flow of assessment, using these factors, and aligned with concepts identified in previous literature of severity, assessment of assistance required, and assessment of volitional control.

Keywords: Lokomat, robotic, cardiovascular exercise, aerobic exercise, subacute stroke, transition, treadmill

Subject: Public Health thesis

Thesis type: Masters
Completed: 2020
School: College of Nursing and Health Sciences
Supervisor: Christopher Barr