Movement Control after Stroke Studies on Sit-to-walk and on the Relations between Clinical and Laboratory Measures

University dissertation from Uppsala : Acta Universitatis Upsaliensis

Abstract: Aims: The principal aims of this research were 1) to extend existing knowledge of the everyday sit-to-walk (STW) transfer in subjects with stroke and in matched controls by exploring temporal, kinematic, and kinetic aspects, and 2) to investigate the relations between some clinical and laboratory measures of postural control and locomotion in stroke rehabilitation and research.Methods: Ten community-living subjects with stroke (mean age 59 years) and ten matched controls were enrolled in the STW studies (Studies I, II, and IV). In the study regarding relations between clinical and laboratory measures the same samples (part of Study II) and also 20 outpatient subjects with stroke (mean age 50 years) participated (Study III). Data collections were performed in laboratory environments with clinical assessment instruments, video cameras, force plates and a movement analysis system.Results: 1) Study I: A temporal aspect of STW was studied. Four phases were defined. The subjects with stroke used significantly more time during the 2nd STW phase, defined from seat-off to the loading peak of the 1st swing leg. Study II: A movement aspect of STW was investigated. The stroke subjects generated significantly less centre of mass momenta in horizontal and vertical directions, and the momenta peaks occurred significantly earlier than in the controls. Study IV: A force aspect of STW was explored. The subjects with stroke generated significantly larger propulsive impulse beneath the (non-paretic) stance buttock and significantly more braking impulses were exerted by both buttocks and particularly by the stance foot.2) Part of Study II: A strong correlation was found between the clinical measure Fluidity Scale and the laboratory measure Fluidity Index. Study III: Moderate correlations were shown between Berg Balance Scale, ratings of weight distribution during quiet stance, and force measures.Conclusions: The findings of the STW studies show a changed force interaction between the lower extremities post-stroke, likely influencing movement patterns and temporal characteristics of the everyday transfer. The results are considered to reflect compensatory motor strategies. The results of the studies on relations between some clinical and laboratory measures indicate that the strength of the relation is multidimensional.