Evaluation the effects of different dual task conditions on gait and balance performance in people with Multiple Sclerosis

Title: Evaluation of the Effects of Different Dual-Task Conditions on Gait and Balance Performance in People with Multiple Sclerosis Purpose: The aim of this study was to investigate the effects of different dualtask conditions on gait spatiotemporal parameters, pelvic kinematics, and dynamic balance in people with early-stage Multiple Sclerosis (MS). Methods: This cross-sectional study included 36 MS patients who were able to walk independently and had an EDSS < 5. Performances were evaluated under Single Task (ST), Complex Motor Dual Task (CMDT) and Complex Cognitive Dual Task (CCDT) conditions. Spatiotemporal data were measured using a wearable gait analysis device, and dynamic balance was assessed using the Four Square Step Test. Dual-Task Cost was calculated using the formula [((DT duration – ST duration) / ST duration) *100]. Results: Gait and balance test completion times were statistically significantly longer in the CCDT compared to the ST and CMDT (p<0,001). CCDT cadence values were statistically significantly lower than those of ST (p<0,05). Total pelvic obliquity and rotation values were statistically significantly lower in both dual-tasks compared to ST. The cognitive cost of CCDT was statistically significantly higher than the motor cost of CMDT in both gait and balance (p<0,001). CCDT balance cost showed a positive correlation with fear of falling and dual-task difficulties (p<0,05), and a negative correlation with cognitive processing speed. Conclusion: The disruptive effect of cognitive tasks on gait and balance in early-stage MS is more pronounced than that of motor tasks. Patients developed a compensatory strategy by stabilizing the pelvis to maintain stability and reduce the risk of falling under increased cognitive load. To detect disease progression and fall risk at an early stage, the integration of cognitive-motor dual-task protocols and pelvic kinematic analyses into routine clinical examinations is recommended. Keywords: Balance, Dual Task, Dual Task Cost, Multiple Sclerosis, Gait