First validation of a novel assessgame quantifying selective voluntary motor control in children with upper motor neuron lesions

Abstract

The question whether novel rehabilitation interventions can exploit restorative rather than compensatory mechanisms has gained momentum in recent years. Assessments measuring selective voluntary motor control could answer this question. However, while current clinical assessments are ordinal-scaled, which could affect their sensitivity, lab-based assessments are costly and time-consuming. We propose a novel, interval-scaled, computer-based assessment game using low-cost accelerometers to evaluate selective voluntary motor control. Participants steer an avatar owl on a star-studded path by moving the targeted joint of the upper or lower extremities. We calculate a target joint accuracy metric, and an outcome score for the frequency and amplitude of involuntary movements of adjacent and contralateral joints as well as the trunk. We detail the methods and, as a first proof of concept, relate the results of select children with upper motor neuron lesions (n = 48) to reference groups of neurologically intact children (n = 62) and adults (n = 64). Linear mixed models indicated that the cumulative therapist score, rating the degree of selectivity, was a good predictor of the involuntary movements outcome score. This highlights the validity of this assessgame approach to quantify selective voluntary motor control and warrants a more thorough exploration to quantify changes induced by restorative interventions.

Validity and reliability of an accelerometer-based assessgame to quantify upper limb selective voluntary motor control

“…Before statistically analyzing the data, missing data points due to sensor errors were imputed with the mean value resulting from multiple imputation by chained equation. For detailed information we refer to our methods paper [15].…”

“…The assessgame was created in collaboration with Reha-Stim Medtech AG (previously YouRehab, Schlieren, Switzerland). Its technical features and in depth description can be found in a separate methods paper [15]. In short, the assessgame uses accelerometers and bend sensors (cyber-gloves for fingers) to capture target joint movements and (potentially) simultaneously occurring involuntary movements.…”

“…The assessgame provides two outcome measures, one for the accuracy of the target joint movement and one combined value for the involuntary movements. Further information on the exact algorithm used to generate these outputs can also be found in the methods paper [15]. In summary (Fig.…”

“…The data were filtered using a 6th order Butterworth zero-phase low-pass filter with a cutoff frequency of 1.5 Hz (normalized cutoff frequency of 0.045). Reprinted from 'First validation of a novel assessgame quantifying selective voluntary motor control in children with upper motor neuron lesions' [15] handle objects easily and successfully whereas level 5 indicates that patients do not handle objects at all [17]. Medical professionals in our rehabilitation center routinely assess the MACS level in children with CP.…”

Validity and reliability of the Selective Control of the Upper Extremity Scale in children with upper motor neuron lesions

“…Intra-rater and inter-rater reliability has been investigated in both studies [16,17], showing acceptable to excellent intra-class correlation coefficient (ICC) values for joints and sum scores. The SCUES has further served to validate a novel SVMC assessgame [18,19].…”