The size and behavior of virtual objects have influence on functional exercise and motivation of persons with multiple sclerosis: a randomized study

The consequences of multiple sclerosis are problems with limb movement, coordination, and vision. Heretofore a combination of therapy and additional medications can alter the course of the disease and reduce upper extremity disability. We developed a virtual environment for pick-and-place tasks as a supportive tool to address the problem of challenging task in occupational therapy. The primary objective of the study was to investigate the influence of size and bounce on proximal and fine motor performance and intrinsic motivation. The secondary objective was to examine how the absence of challenge may decrease intrinsic motivation and heart rate. The randomized trial involved 84/107 eligible inpatients with multiple sclerosis. They were divided into 4 groups by computer randomization: Group 1 small and bouncing, Group 2 small and non-bouncing, Group 3 large and bouncing, and Group 4 large and non-bouncing virtual cubes. Each participant completed 50 sessions of up to 2 min each in approximately 14 days. Before commencement of the study the participants completed visuospatial and cognitive tests. Participants' subjective experiences were assessed daily using the intrinsic motivation inventory. Before and after the study, the box and block test and the 9-hole peg test were administered. Kinematic analysis showed significant differences between groups (average manipulation time p = 0.008, inserted cubes p = 0.004). Group 4 was the most successful (inserted cubes > 9) and the fastest (63.4 SD 25.8 s), but had low pressure/tension and heart rate. Group 1 was the slowest (88.9 SD 28.2 s) but had increased interest/enjoyment in the task under higher pressure/tension. There were substantial differences in intrinsic motivation between the 1st and last sessions within groups (Cohen's U3 < 0.3 or > 0.8). The size and behavior of virtual objects may be important for training proximal movements and fine motor skills in people with multiple sclerosis. Furthermore, the demonstrated approach proved to be effective and may reduce upper extremity disability in the long term if intrinsic motivation can be sustained longer with a challenging task. Trial registration The small scale randomized pilot trial has been registered at ClinicalTrials.gov Identifier: NCT04266444, 12/02/2020, https://clinicaltrials.gov/ct2/show/NCT04266444.