Effect of task difficulty on dual-task cost during dual-task walking in people with multiple sclerosis

• Published in: Gait & posture Vol. 114; pp. 95 - 100
• Main Authors: GÜLŞEN, Çağrı, SÖKE, Fatih, AYDIN, Fatma, ÖZCAN GÜLŞEN, Elvan, YILMAZ, Öznur, KOÇER, Bilge, ÇÜRÜK, Etem, DEMİRKAYA, Şeref, YÜCESAN, Canan
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.10.2024
• Subjects: Dual-task; Motor-cognitive tasks; Multiple sclerosis; Task difficulty; Walking; Task difficulty; Walking; Dual-task; Multiple sclerosis; Motor-cognitive tasks
• ISSN: 0966-6362; 1879-2219; 1879-2219
• DOI: 10.1016/j.gaitpost.2024.09.003

Cognitive-motor dual-task walking results a decrease in walking performance of patients with multiple sclerosis (PwMS) and it is known as dual-task cost (DTC). However, there is a lack of evidence about the effects of dual-tasks with hierarchical difficulty on DTC in PwMS. This study aimed to investigate the effect of task difficulty on DTC during cognitive-motor dual-task walking in people with multiple sclerosis (PwMS). 32 PwMS and 32 healthy controls were included. The 6-meter walking test (6-Meter WT) with comfortable speed was used as single-task walking condition. For dual-task conditions, walking tasks and cognitive tasks at two difficulty levels (simple and difficult) were combined and DTC for four cognitive-motor dual-task walking conditions as simple motor-simple cognitive (SM-SC), simple motor-difficult cognitive (SM-DC), difficult motor-simple cognitive (DM-SC) and difficult motor-difficult cognitive (DM-DC) were calculated. The 6-Meter WT was used also for simple dual-task walking task. The 6-Meter WT was applied by walking in a narrow base condition for creating a difficult dual-task walking task. For cognitive task difficulty, participants were asked to count backwards by 3 as simple cognitive task and by 7 as difficult cognitive task. DTC was higher in PwMS than control subjects. DTC in all conditions were different (SM-SC<SM-DC<DM-SC<DM-DC). DTC was higher in PwMS than control subjects in three conditions and was similar SM-SC condition. In addition, DTC in all conditions (SM-SC<SM-DC<DM-SC<DM-DC) were different in both PwMS and control subjects. The results suggest that task difficulty affects the magnitude of DTC during cognitive-motor dual-task walking in PwMS. Moreover, difficult walking tasks combined with simple cognitive tasks result greater DCT on walking than simple walking tasks combined with difficult cognitive tasks. •DTC was higher in PwMS than control subjects.•Task difficulty affects the magnitude of DTC during cognitive-motor dual-task walking.•Difficult walking tasks combined with simple cognitive tasks result greater DCT.