Cardiovascular rehabilitation soon after stroke using feedback-controlled robotics-assisted treadmill exercise: study protocol of a randomised controlled pilot trial

Abstract

Background: After experiencing a stroke, most individuals also suffer from cardiac disease, are immobile and thus have low endurance for exercise. Aerobic capacity is seriously reduced in these individuals and does not reach reasonable levels after conventional rehabilitation programmes. Cardiovascular exercise is beneficial for improvement of aerobic capacity in mild to moderate stroke. However, less is known about its impact on aerobic capacity, motor recovery, and quality-of-life in severely impaired individuals. The aim of this pilot study is to explore the clinical efficacy and feasibility of cardiovascular exercise with regard to aerobic capacity, motor recovery, and quality-of-life using feedback-controlled robotics-assisted treadmill exercise in non-ambulatory individuals soon after experiencing a stroke.

Methods/design: This will be a single-centred single blind, randomised control trial with a pre-post intervention design. Subjects will be recruited early after their first stroke (≤20 weeks) at a neurological rehabilitation clinic and will be randomly allocated to an inpatient cardiovascular exercise programme that uses feedback-controlled robotics-assisted treadmill exercise (experimental) or to conventional robotics-assisted treadmill exercise (control). Intervention duration depends on the duration of each subject's inpatient rehabilitation period. Aerobic capacity, as the primary outcome measure, will be assessed using feedback-controlled robotics-assisted treadmill-based cardiopulmonary exercise testing. Secondary outcome measures will include gait speed, walking endurance, standing function, and quality-of-life. Outcome assessment will be conducted at baseline, after each 4-week intervention period, and before clinical discharge. Ethical approval has been obtained.

Discussion: Whether cardiovascular exercise in non-ambulatory individuals early after stroke has an impact on aerobic capacity, motor recovery, and quality-of-life is not yet known. Feedback-controlled robotics-assisted treadmill exercise is a relatively recent intervention method and might be used to train and evaluate aerobic capacity in this population. The present pilot trial is expected to provide new insights into the implementation of early cardiovascular exercise for individuals with severe motor impairment. The findings of this study may guide future research to explore the effects of early cardiovascular activation after severe neurological events.

Trial registration: This trial is registered with the Clinical Trials.gov Registry (NCT01679600).

Figure 1

Flow chart outlining the study protocol. A 4-week intervention period includes baseline assessments (t0) and first post-intervention (t1) assessments (solid line). The dashed line represents a potential continuation of the intervention due to extended inpatient rehabilitation. Post-intervention assessments will be conducted after every 4-week intervention period and before clinical discharge.

Figure 2

Feedback-controlled robotics-assisted treadmill exercise. The solid line represents the mechanical work rate (P_mech) produced by the subject. The dashed line represents the target work rate (P*_mech). The passive mechanical work rate (P_passive) is evaluated before every session and subtracted from P_mech. Legend: P_raw = raw mechanical work rate, M_i = moments of force, ω_i = angular velocity, P_total = total mechanical work rate.

Figure 3

Exercise testing protocols. Schematic representation of constant load testing (A) and incremental exercise testing (B) using feedback-controlled robotics-assisted treadmill exercise. The solid line represents the mechanical work rate (P_mech) produced by the subject. The dashed line represents the target work rate (P*_mech). The slope will be estimated such that the predefined peak work rate is reached after 10 minutes. When individual termination criteria are met the incremental phase is ended and P*_mech set back to the passive level.