earticle

영어

Purpose: This study investigated the effects of squat exercises performed under different levels of support surface stability on lower limb muscle architecture in individuals with subacute stroke. Specifically, this study aimed to compare the changes in muscle thickness and pennation angle of the paretic tibialis anterior and medial gastrocnemius muscles between stable and unstable support surface conditions. Methods: Twenty-six individuals with subacute stroke were randomly allocated to either the unstable surface group (n=13) or stable surface group (n=13). Both groups participated in a 4-week intervention consisting of conventional rehabilitation combined with a standardized squat exercise program performed five times per week. The squat depth (approximately 60° knee flexion) and movement speed were controlled using a goniometer and metronome. The muscle thicknesses of the tibialis anterior and medial gastrocnemius, as well as the pennation angle of the medial gastrocnemius were assessed using rehabilitative ultrasound imaging before and after the intervention. Within-group changes were analyzed using paired t-tests and between-group differences in change scores were examined using independent t-tests. Results: Both groups demonstrated significant increases in tibialis anterior thickness, medial gastrocnemius thickness, and medial gastrocnemius pennation angle after the intervention (p<.01). However, the unstable-surface group showed significantly greater improvements in all outcome variables than the stable-surface group (p<.05), indicating larger structural adaptations of the paretic lower limb muscles under unstable support surface conditions. Conclusions: Squat exercises performed on an unstable support surface induced greater increases in the muscle thickness and pennation angle of the paretic lower limb than those performed on a stable surface. These findings suggest that incorporating unstable support surfaces into squat training may provide additional benefits in promoting neuromuscular and structural adaptations in individuals with subacute stroke. Further studies are required to examine whether these architectural changes translate into functional improvements.