Asymmetry of thoracic expansion in hemiplegic stroke and its relationship with physical function and percent vital capacity: A cross-sectional study.

BACKGROUND

Thoracic expansion (TE) is associated with respiratory muscle strength and pulmonary function. However, in patients with stroke who present unilateral motor impairment, the relationship between asymmetry in TE measured bilaterally, physical function, and percent vital capacity (%VC) remains unclear.

OBJECTIVE

This study aimed to investigate differences in TE between the sound and hemiplegic sides in patients with stroke, and to examine the associations between TE asymmetry, physical function, and %VC.

METHODS

Forty male patients with post-stroke hemiplegia were enrolled. TE was measured bilaterally using a unilateral measurement method developed previously. Differences between the sound and hemiplegic sides were analyzed. TE difference and an asymmetry index were calculated, and their correlations with physical function and %VC were examined. Participants were classified into symmetric and asymmetric groups and physical function and %VC were compared between the two groups.

RESULTS

TE on the hemiplegic side was significantly lower than that on the sound side. The asymmetry index showed moderate correlations of TE with physical function, demonstrating broader associations than simple side-to-side differences. The results of the between group comparisons showed that classification based on the asymmetry index more clearly reflected the decline in physical function and %VC. Adjusted %VC was 12.9% higher in the symmetric group, but the difference was not significant.

CONCLUSIONS

In stroke patients, TE on the hemiplegic side is significantly reduced. When quantified using the asymmetry index, it may serve as a practical and clinically relevant assessment parameter of functional decline.