In-Phase Bilateral Upper Limb Exercises Improve Cognitive and Motor Functions in Progressive Multiple Sclerosis: A Pilot Randomized Controlled Trial

<b>Background and Purpose:</b> Progressive multiple sclerosis impairs cognitive and motor functions and reduces quality of life. Complex goal-directed movements are challenging due to cognitive deficits, whereas in-phase bilateral exercises require less attentional demand and cognitive effort. This type of exercise may therefore improve both cognitive and motor functions. Previous studies in people with progressive multiple sclerosis suggested a strong association between cognitive and upper limb functions; however, the effects of in-phase bilateral exercises remain unclear. <b>Objectives:</b> To evaluate the effects of in-phase bilateral upper limb exercise on cognitive processing, motor functions, and quality of life in people with progressive multiple sclerosis. <b>Methods:</b> Twenty participants (11 females, mean age = 55.8 years) were randomized (1:1) to an experimental or active control group for a 12-week intervention. The experimental group performed in-phase bilateral upper limb exercises while the active control group performed conventional exercises. ANOVA was conducted to determine the effect of intervention on information processing speed, motor function, fatigue, and quality of life. <b>Results:</b> Post hoc analyses revealed that the experimental group demonstrated significantly greater improvements than the active control group in information processing speed (<i>t</i>(18) = 8.6, <i>p</i> < 0.05), as well as across all exploratory secondary outcome measures (all <i>p</i> < 0.05). <b>Conclusions:</b> This pilot randomized controlled trial suggests that in-phase bilateral exercises, which demand less cognitive effort than other forms of bilateral coordination, are associated with improvements in information processing speed, motor functions, fatigue, and quality of life in people with progressive multiple sclerosis.