Comparative effects of square-stepping and strengthening exercises on cognitive and balance functions in chronic obstructive pulmonary disease: a randomized clinical trial

Cognitive impairment and balance dysfunction are common in individuals with chronic obstructive pulmonary disease (COPD), yet targeted interventions remain limited. Square-stepping exercise (SSE), a structured multitasking intervention involving progressive, multi-directional step patterns, combines cognitive and motor challenges. This study aimed to compare the effects of SSE and traditional strengthening exercises (SE) on cognitive function and balance in individuals with COPD through a telerehabilitation model.

Methods

This randomized clinical trial included 34 male individuals with mild to moderate COPD (mean age: 63.91 ± 6.98 years), randomly assigned to SSE and SE groups ( n  = 17 each). Both groups participated in supervised telerehabilitation sessions three times per week for eight weeks. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA; 0–30 points, with higher scores indicating better cognition), while the Standardized Mini-Mental State Examination (SMMSE; 0–30, cutoff < 23) was used as a screening tool to exclude significant cognitive impairment. Balance performance was evaluated using the Biodex Balance System, including the overall stability index, anterior/posterior index, and medial/lateral index (lower scores indicate better balance). Perceived breathlessness (dyspnea) was assessed with the Modified Medical Research Council (mMRC) scale (0–4), and disease impact with the COPD Assessment Test (CAT; 0–40, ≥10 indicating high symptom burden). Comorbidity severity was evaluated using the modified Charlson Comorbidity Index (CCI; higher scores indicate greater severity). Data normality was assessed using the Shapiro–Wilk test. Independent sample t-tests were used for parametric between-group comparisons, and Mann–Whitney U tests were applied for non-parametric data. Paired sample t -tests and Wilcoxon signed-rank tests were used for within-group comparisons. The level of statistical significance was set at p  < 0.05.

Results

Both groups showed significant within-group improvement in MoCA scores ( p  = 0.01 for both). However, the SSE group demonstrated greater improvements in balance parameters, particularly in the overall stability index ( p  = 0.014) and anterior/posterior stability index ( p  = 0.05), compared to the SE group. The SE group showed limited improvements, primarily in static balance conditions ( p  = 0.029). Although cognitive gains were similar between the groups, balance improvements were more pronounced in the SSE group.

Conclusions

While both exercise modalities improved cognitive function in individuals with COPD, SSE led to superior outcomes in balance control. The multitasking design of SSE, requiring simultaneous cognitive processing and motor coordination, may underlie its enhanced impact on postural stability. These findings support SSE as a technically advantageous and accessible intervention in telerehabilitation for individuals with COPD.