Interference of Various Sources of Sensory Feedback on Transition of Relative Phase in Bimanual Coordination on Active and Inactive Woman With Multiple Sclerosis

Purpose: Comparing the effects of manipulating senses on relative phase transition bimanual coordination pattern of active and inactive women with Multiple Sclerosis (MS). Methods: The methodology of this study was repeated-measures design. Study participants comprised 10 active women and 10 inactive women with multiple sclerosis who voluntarily participated in this experiment. The participants (n=20; aged 18-25 years) performed bimanual in-phase and anti-phase movements with their wrists at three different speeds ranging from slow to fast and 5 different sensory conditions, including 1) normal sensory input, 2) masked vision, 3) masked proprioception, 4) masked audition, and 5) full sensory deprivation. Two-way (5 sensory conditions×2 groups) analyses of variance for repeated measures (ANOVA) were performed using SPSS 24.  Results: The findings showed that the main effect of the senses and groups was not significant, while the effect of interaction between the senses and groups was significant (P=0.047). Accordingly, there was a significant difference between two groups with regard to the manipulation of proprioception, vision, and audition conditions. Regarding the effect of different senses in both active and inactive women with MS, only a significant effect was observed between two groups in manipulation of proprioception condition, when vision and audition were not manipulated (P=0.004). Also, comparing active and inactive woman with MS in different manipulated sensory conditions did not reveal significant differences. Conclusion: Proprioception in both active and inactive woman with MS has a significant impact on performing bimanual coordination task.