Analysis of upper limb movement in hemiplegic patients after stroke: An investigation of effects of visual, rhythmic and melodic auditory cues on movement patterns

Abstract

Stroke is one of the leading causes of death in worldwide, which requires continuous rehabilitation for patients who suffered from its aftereffect. Musical cueing has been considered as one of the major modalities for the post-stroke motor rehabilitation; however, little is known about the kinematic effects of musical cueing on rehabilitation. Few studies have investigated the element-specific effects of musical cueing on upper-limb movements. This study aimed at the kinematic quantification of the effects of various auditory cueing on shoulder abduction, holding, and adduction in patients who had past history of hemiparetic stroke. Through IMUs embedded in wearable bands, several kinds of kinematic data could be obtained. According to the kinematic data of the participants, melodic auditory cueing significantly increased their minimum Euler angle and decreased the range of motion when compared with the other types of cueing during the holding phase. The data shows the significant improvement concerning the root mean square error in the angle measurements and duration of movement execution during the holding phase with the help of melodic auditory cueing compared with the other types of cueing. This result reveals the critical role of melodic auditory cueing to enhance movement positioning, variability, and endurance. Based on the results showing that pitch can provide a cognitive element of movement in terms of vertical direction and spatial position, the group of hemiplegic patients was classified into four groups with kinematic characteristics. It was divided into two groups as severe (stage 3, 4) and mild (stage 5, 6) according to the brunnstrom recovery stage after stroke, and classified into cortical and subcortical depend on which part of the brain is affected. As a result of analyzing the effect of visual, rhythmic and melodic auditory cueing on movement patterns in each group, movement time was most accurate when visual cueing was provided, and rhythmic auditory cueing was more accurate than melodic auditory cueing. Isochronous rhythm is effective in improving the accuracy of movement timing over melodic auditory cueing in periodic and repetitive movements, as it strengthens the entrainment between movement and external auditory rhythms. Melodic auditory cueing affected a higher range of motion during abduction and adduction, and the less movement variability was maintained as the range of motion was small in the holding phase. Tremor occurs as a common behavioral characteristic of the two groups classified according to the location of the lesion in the brain. As a result of analysis by the linear regression model, there was no significant difference in the cortical group and subcortical group, and the melody signal significantly lowered the tremor than other signals. This study provides several pieces of kinematic evidence on the effects of melodic auditory cueing on kinematic enhancement, which suggests an application of pitch-related elements in psychomotor rehabilitation.