Predicting the oxygen cost of walking in hemiparetic stroke patients

International audienceOBJECTIVE:To verify the relation between spontaneous walking speed (Sfree) and oxygen cost of walking at Sfree (Cwfree) in post-stroke hemiparetic patients and to test the validity of a prediction model to estimate Cwfree based on Sfree.DESIGN:We included 26 participants (mean age 65.1 years [SD 15.7]) with mild to moderate disability after stroke who walked at Sfree using mobility aids if necessary for 6min. The Cwfree was measured at a stabilized metabolic rate by indirect calorimetry with the Metamax 3B spiroergometry device. The relation between Sfree and Cwfree was analyzed by the correlation coefficient (r) and coefficient of determination (R2). The Cwfree prediction model was developed from a regression equation, then tested on a second population of 29 patients (mean age 62.1 years [SD 13.4]) with the same inclusion and exclusion criteria.RESULTS:For the 26 participants, the Sfree and Cwfree were highly correlated (r=-0.94 and R2=0.97), which allowed for formulating a regression equation and developing the Cwfree prediction model based on Sfree. The prediction model tests yielded accurate results (mean bias -0.02mL.kg-1.m-1; 95% limits of agreement -0.31 to 0.26mL.kg-1.m-1). The relation between Cwfree estimated by the model and measured by Metamax was high (R2=0.98).CONCLUSION:Cwfree was strongly correlated with Sfree, which allowed for the development of a valid Cwfree prediction model. A practitioner could estimate the energy expenditure of walking for a patient without using an indirect calorimeter

Patients AVC et marche : Association du statut fonctionnel à l’activation du cortex préfrontal

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Validity of wearable actimeter computation of total energy expenditure during walking in post-stroke individuals

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Age and gender differences in motor imagery.

International audienceBACKGROUND:Few studies have explored the effects of ageing and gender in the dimensions of motor imagery (MI) such as vividness (vivid images and sensations of mental movements) and timing (the duration of an imagined movement). This study aims 1) to investigate the effect of age and gender effect in vividness and timing capabilities on MI, and 2) to examine the relationship between these two dimensions of MI.METHODS:A population of 72 (47% of males) good imagers including 41 young subjects and 31 older subjects were assessed on MI vividness using the Vividness of Movement Imagery Questionnaire (VMIQ-2) and on MI timing using the performances of the real Timed Up and Go (rTUG) test and its imagined version (iTUG). The main outcome variables were the VMIQ-2 score and the delta-TUG, i.e. the difference between rTUG and iTUG.RESULTS:Mental vividness was affected by ageing with a loss of visual dominance in favor of kinesthetic imagery in older subjects compared to younger ones; however, no difference between both groups was found in timing measured by delta-TUG. Vividness capabilities were similar between men and women, but women performed better in timing. VMIQ-2 scores were not associated with delta-TUG; only gender was significantly associated with delta-TUG.CONCLUSIONS:This study revealed 1) an age-related transfer from a visual to a kinesthetic MI ability, but no impact on timing of MI; 2) a gender effect on timing with no impact on mental vividness; 3) no association between vividness and timing capabilities