Does motivation matter in upper-limb rehabilitation after stroke? ArmeoSenso-Reward: study protocol for a randomized controlled trial

Abstract

Background: Fifty percent of all stroke survivors remain with functional impairments of their upper limb. While there is a need to improve the effectiveness of rehabilitative training, so far no new training approach has proven to be clearly superior to conventional therapy. As training with rewarding feedback has been shown to improve motor learning in humans, it is hypothesized that rehabilitative arm training could be enhanced by rewarding feedback. In this paper, we propose a trial protocol investigating rewards in the form of performance feedback and monetary gains as ways to improve effectiveness of rehabilitative training.

Methods: This multicentric, assessor-blinded, randomized controlled trial uses the ArmeoSenso virtual reality rehabilitation system to train 74 first-ever stroke patients (< 100 days post stroke) to lift their impaired upper limb against gravity and to improve the workspace of the paretic arm. Three sensors are attached to forearm, upper arm, and trunk to track arm movements in three-dimensional space while controlling for trunk compensation. Whole-arm movements serve as input for a therapy game. The reward group (n = 37) will train with performance feedback and contingent monetary reward. The control group (n = 37) uses the same system but without monetary reward and with reduced performance feedback. Primary outcome is the change in the hand workspace in the transversal plane. Standard clinical assessments are used as secondary outcome measures.

Discussion: This randomized controlled trial will be the first to directly evaluate the effect of rewarding feedback, including monetary rewards, on the recovery process of the upper limb following stroke. This could pave the way for novel types of interventions with significantly improved treatment benefits, e.g., for conditions that impair reward processing (stroke, Parkinson's disease).

Trial registration: ClinicalTrials.gov, ID: NCT02257125 . Registered on 30 September 2014.

Keywords: Arm; Feedback; Rehabilitation; Reward; Stroke; Upper extremity; Virtual reality.

Conflict of interest statement

Ethics approval and consent to participate

The study will follow Good Clinical practice (GCP) guidelines and has been approved by the responsible local Ethics Committees “Ethikkommission Nordwest- und Zentralschweiz,” the “Kantonale Ethikkommission Zürich” (LU2013-079 and PB_2016-01804) and the Swiss Agency for Therapeutic Products (Swissmedic: 2014-MD-0033). All subjects have to give written informed consent in accordance with the Declaration of Helsinki.

Consent for publication

Written informed consent was obtained from the participant (Fig. 2a) for publication of this photograph in this manuscript. The Informed Consent Form is held by the authors and is available for review by the Editor-in-Chief.

Competing interests

Andreas R. Luft is a scientific advisor to Hocoma AG (Volketswil). The remaining authors have no conflict of interest in the submission of this manuscript.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1

Flow diagram illustrating the trial design and sequence

Fig. 2

a Healthy subject using the ArmeoSenso training system. b Arm workspace assessment: gray cubic voxels arranged in the transverse plane reflecting 10 cm × 10 cm active workspace relative to the patient’s trunk

Fig. 3

a ArmeoSenso-Reward: “METEORS” therapy game. The hand of the virtual arm is used to catch the falling meteors before they crash onto the planet. If caught, the meteor explodes and a score appears. If missed, the planet gets damaged (note the impact crater). The current score (= PUNKTE) is displayed on the upper left (white font color) and compared to the patient’ all-time record (= REKORD; red font color, upper left). The green bar on the upper right indicates resting time. If completely black, the patient has to rest for 4 s before new meteors are spawned. During rest, the bar fills with green. The yellow bar on the left indicates how much playtime is left in the ongoing round (maximum 150 s). b Control game. The virtual hand is a green decagon that can be used to touch the pill-shaped, single-colored targets dropping in from the top of the screen, which then disappear with a delay of 1 s without producing a score. The green bar on the upper right fills up whenever the patient assumes the resting position

Fig. 4

ArmeoSenso-Reward feedback screens. a “PLANETEN GERETTET”: planet saved. This screen is presented after each completed round. The number of meteors caught (“GEFANGEN”, top) and meteors hitting the planet (“EINGESCHLAGEN”, bottom) is indicated on the left. The monetary reward (“GEWINN”) for the current round (“DIESE RUNDE”, top), the current day (“HEUTE”, middle) and the total amount of money gathered over the course of the study (“TOTAL”, bottom) are displayed on the right. Note that a maximum of 1 Swiss Franc (CHF) can be won per round. b Hall of fame (“RUHMESHALLE”) with the patient’s top 10 scores. If the current score is in the top 10, it is highlighted in red

Fig. 5

Standard Protocol Items: Recommendation for Interventional Trials (SPIRIT) Figure. The schedule of enrollment, interventions and assessments