Relationship between movement asymmetry and sit-to-stand/stand-to-sit duration in patients with hemiplegia

Abstract

Objective: To elucidate the relationship between side-to-side asymmetry and sit-to-stand and stand-to-sit duration in patients with right or left hemiplegia by three-dimensional motion analysis of the two movements. Methods: Forty-five patients with hemiplegia (right hemiplegia in 21, left hemiplegia in 24) and 20 normal healthy adults were studied. Using three-dimensional motion analysis, an asymmetry index (AI) was calculated from the trajectory of the left-right component at the midpoint between two acromion markers as a function of time. Normal range of the sit-to-stand and stand-to-sit duration was calculated as the mean ± SD obtained from normal subjects. Patients were divided into two groups according to duration: normal duration (within the mean ± 2SD of normal subjects) and abnormal duration (outside the mean ± 2SD of normal subjects). Motor function of the affected lower extremity and other parameters were compared between the normal and abnormal duration groups. Results: Sit-to-stand and stand-to-sit duration was significantly prolonged in both right hemiplegic and left hemiplegic patients compared with normal subjects. In left hemiplegic patients, AI was significantly higher in those with abnormal duration for both sit-to-stand and stand-to-sit movements. In left hemiplegic patients, the lower extremity motor function was significantly poorer in those with abnormal duration for sit-to-stand movement. Conclusion: In patients with left hemiplegia, AI deviates toward the unaffected side, and impaired lower extremity motor function is associated with prolonged sit-to-stand duration.