RESUMEN
When two tasks are performed simultaneously, they compete for attentional resources, resulting in a performance decrement in one or both tasks. Patients with attention disorders have a reduced ability to perform several tasks simultaneously (e.g., talking while walking), which increases the fall risk and frailty. This study assessed the cognitive and motor performances of patients with COPD and healthy controls within a dual-task walking paradigm. A subobjective was to assess the impact of a pulmonary rehabilitation program on the dual-task performances in COPD. Twenty-five patients with COPD and 20 controls performed a cognitive task (subtraction) and a 15-m walking test separately (single-task; ST) and jointly (dual-task; DT). In addition, a subsample of 10 patients performed the same evaluations 5 weeks later after a pulmonary rehabilitation program following current recommendations. Cognitive and gait performances in ST showed no differences between patients with COPD and controls (all p > 0.05). However, COPD patients exhibited a greater increase in gait variability than controls in DT (4.07 ± 1.46% vs. 2.17 ± 0.7%, p < 0.001). The pulmonary rehabilitation program had no effect on the dual-task impairment for the subsample of patients (p = 0.87). This study provides evidence of insufficient attentional resources to successfully deal with DT in patients with COPD, and this was expressed through an exaggerated increase in gait variability in DT walking. Given the high risk of falls and disability associated with altered gait variability, dual-task training interventions should be considered in pulmonary rehabilitation programs.