Robot-supported upper limb training in a virtual learning environment : a pilot randomized controlled trial in persons with MS

Abstract

Background: Despite the functional impact of upper limb dysfunction in multiple sclerosis (MS), effects of intensive exercise programs and specifically robot-supported training have been rarely investigated in persons with advanced MS.

Aim: To investigate the effects of additional robot-supported upper limb training in persons with MS compared to conventional treatment only.

Methods: Seventeen persons with MS (pwMS) (median Expanded Disability Status Scale of 8, range 3.5-8.5) were included in a pilot RCT comparing the effects of additional robot-supported training to conventional treatment only. Additional training consisted of 3 weekly sessions of 30 min interacting with the HapticMaster robot within an individualised virtual learning environment (I-TRAVLE). Clinical measures at body function (Hand grip strength, Motricity Index, Fugl-Meyer) and activity (Action Research Arm test, Motor Activity Log) level were administered before and after an intervention period of 8 weeks. The intervention group were also evaluated on robot-mediated movement tasks in three dimensions, providing active range of motion, movement duration and speed and hand-path ratio as indication of movement efficiency in the spatial domain. Non-parametric statistics were applied.

Results: PwMS commented favourably on the robot-supported virtual learning environment and reported functional training effects in daily life. Movement tasks in three dimensions, measured with the robot, were performed in less time and for the transporting and reaching movement tasks more efficiently. There were however no significant changes for any clinical measure in neither intervention nor control group although observational analyses of the included cases indicated large improvements on the Fugl-Meyer in persons with more marked upper limb dysfunction.

Conclusion: Robot-supported training lead to more efficient movement execution which was however, on group level, not reflected by significant changes on standard clinical tests. Persons with more marked upper limb dysfunction may benefit most from additional robot-supported training, but larger studies are needed.

Trial registration: This trial is registered within the registry Clinical Trials GOV ( NCT02257606 ).

Fig. 1

CONSORT flowchart

Fig. 2

Hardware set-up, including a haptic robot, sling and visual display

Fig. 3

Example of basic motor function exercise ‘reach’ (a) and ‘pull’ (b). Participants have to reach or pull the disk towards the target. Visual feedback on the correctness of the executed trajectory is provided by colour changes of the disk (green, orange, red). During pulling, subjects experience resistance on, or are pulled to, the trajectory

Fig. 4

Serious games a ‘Watering the flowers’ and b ‘Chicken run’. a In ‘watering the flowers’, the skill components lifting, transporting and pro/supination are performed while filling a glass with coloured fertilizer and watering the flowers with the matching colour. b ‘Chicken run’ addresses transporting, reaching, pushing and retrieval while collecting eggs and bringing them to the egg-cup. Subjects are prompted to collect as much points as possible in a particular time frame while avoiding distractors

Fig. 5

Proximal (a), distal (b) and total (c) FM score and Motricity Index (d) for subjects 2 and 7, pre- and post-I-TRAVLE training

Fig. 6

Movement duration of transporting exercise and hand path ratio of the reaching exercise for subjects 2 and 7, pre- and post- I-TRAVLE training. Movement duration is expressed in seconds while the Hand Path Ratio is the real distance covered between the two goals divided by the shortest distance between the goals