Gait Training after Stroke on a Self-Paced Treadmill with and without Virtual Environment Scenarios: A Proof-of-Principle Study.

Purpose: The purpose of this proof-of-principle study was to show that virtual reality (VR) technology could be coupled with a self-paced treadmill to further improve walking competency in individuals with chronic stroke. Method: A 62-year-old man with a chronic right hemispheric stroke participated in a treadmill walking programme involving first a control (CTL) protocol, then VR training. In CTL training, he walked without time constraints while viewing still pictures and reacting to treadmill movements similar to those that he would have experienced later in VR training. In VR training, he experienced treadmill movements programmed to simulate changes encountered in five virtual environments rear-projected onto a large screen. Training difficulty in nine sessions over 3 weeks was increased by varying the time constraints, terrain surface changes, and obstacles to avoid. Effects on walking competency were assessed using clinical measures (5 m walk test, 6 min walk test, Berg Balance Scale, Activities-specific Balance Confidence scale) and questionnaires (Assessment of Life Habits Scale and personal appraisal). Results: CTL and VR training resulted in a similar progression through the training sessions of total time walked on the treadmill. The VR training led to an additional increase in speed as measured by walking 5 metres as fast as possible and distance walked in 6 minutes, as well as improved balance self-efficacy and anticipatory locomotor adjustments. As reported by the participant, these improved outcomes transferred to real-life situations. Conclusions: Despite the limited potential for functional recovery from chronic stroke, an individual can achieve improvements in mobility and self-efficacy after participating in VR-coupled treadmill training, compared with treadmill training with the same intensity and surface perturbations but without VR immersion. A larger scale, randomized controlled trial is warranted to determine the efficacy of VR-coupled treadmill training for mobility intervention post-stroke.

Objectif : la présente étude de validation visait à démontrer que la réalité virtuelle (RV) peut être jumelée à un tapis roulant autocontrôlé pour améliorer l'aptitude à marcher des personnes ayant un accident vasculaire cérébral (AVC) chronique. Méthodologie : un homme de 62 ans ayant un AVC chronique de l'hémisphère droit a participé à un programme de marche sur tapis roulant, d'abord au moyen d'un protocole de contrôle (CTL), puis d'un entraînement en RV. Pendant l'entraînement CTL, l'homme a marché sans contrainte de temps tout en regardant des images fixes et en réagissant aux mouvements du tapis roulant semblables à ceux repris par la suite en RV. Pendant l'entraînement en RV, il a ressenti les mouvements du tapis roulant programmés pour simuler les changements observés dans cinq environnements virtuels rétroprojetés sur grand écran. La difficulté de l'entraînement au cours de neuf séances réparties sur trois semaines a augmenté en variant les contraintes de temps, les changements de surface du terrain et les obstacles à éviter. Les chercheurs ont évalué les effets sur l'aptitude à marcher à l'aide de mesures cliniques (tests de marche de cinq mètres et de six minutes, échelle d'évaluation de l'équilibre de Berg, échelle de confiance en l'équilibre pendant des activités) et de questionnaires (échelle d'évaluation des habitudes de vie et évaluation personnelle). Résultats : l'entraînement CTL et celui en RV ont suscité une progression similaire de la durée totale de marche sur le tapis roulant pendant les séances d'entraînement. L'entraînement en RV a favorisé une amélioration supplémentaire de la marche rapide sur cinq mètres et de la distance parcourue en six minutes, de même qu'une meilleure auto-efficacité de l'équilibre et de meilleurs ajustements locomoteurs anticipés. Comme l'a indiqué le participant, cette amélioration des résultats se transposait dans la vie quotidienne. Conclusions : malgré le potentiel limité de récupération fonctionnelle en cas d'AVC chronique, une personne peut améliorer sa mobilité et son auto-efficacité après avoir participé à un entraînement sur tapis roulant jumelé à la RV, par rapport à un entraînement sur tapis roulant de la même intensité et selon les mêmes perturbations de la surface du sol, mais sans l'immersion de la RV. Un essai aléatoire et contrôlé à plus vaste échelle s'impose pour déterminer l'efficacité de l'entraînement sur tapis roulant jumelé à la RV dans le cadre d'une intervention de mobilité après un AVC.

Maximal cardiorespiratory fitness testing in individuals with chronic stroke with cognitive impairment: practice test effects and test-retest reliability.

OBJECTIVES: To evaluate, for individuals with chronic stroke with cognitive impairment, (1) the effects of a practice test on peak cardiorespiratory fitness test results; (2) cardiorespiratory fitness test-retest reliability; and (3) the relationship between individual practice test effects and cognitive impairment. DESIGN: Cross-sectional. SETTING: Rehabilitation center. PARTICIPANTS: A convenience sample of 21 persons (men [n=12] and women [n=9]; age range, 48-81y; 44.9±36.2mo poststroke) with cognitive impairments who had sufficient lower limb function to perform the test. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Peak oxygen consumption (Vo(2)peak, ml·kg(-1)·min(-1)). RESULTS: Test-retest reliability of Vo(2)peak was excellent (intraclass correlation coefficient model 2,1 [ICC2,1]=.94; 95% confidence interval [CI], .86-.98). A paired t test showed that there was no significant difference for the group for Vo(2)peak obtained from 2 symptom-limited cardiorespiratory fitness tests performed 1 week apart on a semirecumbent cycle ergometer (test 2-test 1 difference, -.32ml·kg(-1)·min(-1); 95% CI, -.69 to 1.33ml·kg(-1)·min(-1); P=.512). Individual test-retest differences in Vo(2)peak were, however, positively related to general cognitive function as measured by the Mini-Mental State Examination (ρ=.485; P<.026). CONCLUSIONS: Vo(2)peak can be reliably measured in this group without a practice test. General cognitive function, however, may influence the effect of a practice test in that those with lower general cognitive function appear to respond differently to a practice test than those with higher cognitive function.

Measuring steady-state oxygen uptake during the 6-min walk test in adults with cerebral palsy: feasibility and construct validity.

This study evaluated the feasibility of measuring steady-state oxygen uptake (VO2) during the 6-min walk test (6MWT) in adults with cerebral palsy (CP) who walk without support and whether there is construct validity for net 6MWT VO2 as a measure of their walking ability. Cardiorespiratory variables were assessed at rest and during the 6MWT in 15, independently ambulatory adults, 21-41 years old, with CP. The Gross Motor Function Measure dimensions D and E (GMFM-D and GMFM-E) quantified walking-related skills. Steady-state VO2 was achieved during the 6MWT. After controlling for body mass and speed, the net 6MWT VO2 was strongly related to GMFM-D (r=-0.58, ρ=0.03) and GMFM-E scores (r=-0.66, ρ=0.007). We conclude that for young adults with CP who walk without support, it is feasible to measure steady-state VO2 during the 6MWT and that the net 6MWT VO2 has construct validity as a measure of walking ability.