Factors influencing instability during dual-task walking in stroke patients.

Walking involves multitasking, and many individuals with stroke exhibit dual-task interference, gait instability, and altered lower limb muscle activity even during single-task walking. This study investigated dual-task interference in individuals with stroke and its relationship to single-task walking characteristics. A total of 30 participants completed single-task and dual-task walking. Correct response rate (CRR), dual-task effect, and percentage change in walking speed were assessed using inertial sensors and surface electromyography. The root mean square (RMS) of trunk acceleration and the sample entropy of lower limb acceleration signals were computed. Higher CRR during walking (p = 0.048) and faster walking speed under single-task conditions (p < 0.001) were observed. Mean dual-task effect was - 32.2 %. RMS, sample entropy, and co-contraction index were elevated during dual-task walking (all p < 0.001). Changes in walking speed were associated with co-contraction index (ρ =  - 0.380, p = 0.039), RMS (ρ =  - 0.764, p < 0.001), and sample entropy (ρ =  - 0.734, p < 0.001). Regression analysis indicated that single-task walking speed, RMS, and sample entropy predicted instability during dual-task walking (R2 = 0.545). These results suggest that compromised postural control during single-task walking increases susceptibility to cognitive interference, emphasizing the importance of targeted gait stability training.