Assessment of virtual teacher feedback for the recovery of the upper limb after a stroke. Study protocol for a randomized controlled trial

Introduction: Enhanced feedback provided by virtual reality has been shown to promote motor learning both in healthy subjects and patients with motor impairments following lesions of the central nervous system. The aim of this study is to evaluate the effect of displaying a virtual teacher as visual feedback to promote the recovery of upper limb motor function after a stroke. Methods: The protocol reports the design of a single blind randomized controlled trial (RCT), blinded to outcome assessment. Two different treatments based on virtual reality will be compared: in the "Teacher" group, the patients receive treatment with continuous displaying of a virtual teacher, while in the "No-Teacher" group, the same exercises will be proposed without visualisation of a virtual teacher. The Fugl-Meyer upper extremity scale will be considered as the primary outcome, while the Functional Independence Measure scale, Reaching Performance Scale and Modified Ashworth Scale will be considered as secondary outcomes. Moreover, kinematic parameters such as mean duration (seconds), mean linear velocity (cm/s) and smoothness (i.e. number of sub-movements) will be registered when performing standardised tasks. All tests will be performed before and after treatments. Both treatments will last four weeks with a daily session lasting one hour, five days a week (20 overall sessions). Discussion: This study is designed to systematically assess the influence of using enhanced visual feedback for the recovery of upper limb motor function after a stroke. These findings will help to determine whether the use of a virtual teacher as enhanced visual feedback is effective for promoting better recovery of upper limb motor function over four weeks of post-stroke treatment.