ABSTRACT
Objective@#To examine the relationship between the time constant of oxygen uptake kinetics during the onset of exercise (τVO2) estimated from a single exercise bout and that obtained from three averaged exercise bouts in individuals with stroke. @*Methods@#Twenty participants with stroke performed three bouts of a constant-load pedaling exercise at approximately 80% of the workload corresponding to the ventilatory threshold to estimate τVO2. The VO2 data from the first trial of three bouts were used to estimate τVO2 for a single bout. Additionally, data collected from three bouts were ensemble-averaged to obtain τVO2 for three averaged bouts as the criterion. @*Results@#There was a very high correlation between τVO2 for a single bout (34.8±14.0 seconds) and τVO2 for three averaged bouts (38.5±13.4 seconds) (r=0.926, p<0.001). However, τVO2 for a single bout was smaller than that for three averaged bouts (p=0.006). @*Conclusion@#τVO2 for a single bout could reflect the relative difference in τVO2 for three averaged bouts among individuals with stroke. However, it should be noted that τVO2 for a single bout may be underestimated compared to τVO2 for three averaged bouts.
ABSTRACT
Objective@#To examine the relationship between the time constant of oxygen uptake kinetics during the onset of exercise (τVO2) estimated from a single exercise bout and that obtained from three averaged exercise bouts in individuals with stroke. @*Methods@#Twenty participants with stroke performed three bouts of a constant-load pedaling exercise at approximately 80% of the workload corresponding to the ventilatory threshold to estimate τVO2. The VO2 data from the first trial of three bouts were used to estimate τVO2 for a single bout. Additionally, data collected from three bouts were ensemble-averaged to obtain τVO2 for three averaged bouts as the criterion. @*Results@#There was a very high correlation between τVO2 for a single bout (34.8±14.0 seconds) and τVO2 for three averaged bouts (38.5±13.4 seconds) (r=0.926, p<0.001). However, τVO2 for a single bout was smaller than that for three averaged bouts (p=0.006). @*Conclusion@#τVO2 for a single bout could reflect the relative difference in τVO2 for three averaged bouts among individuals with stroke. However, it should be noted that τVO2 for a single bout may be underestimated compared to τVO2 for three averaged bouts.
ABSTRACT
It has been pointed out that a biased perception of the subjective visual vertical (SVV) in stroke patients might be related to balance deficits and impaired activities of daily living (ADL). The relationship between SVV and static balance in stroke patients, however, still remains unclear. Thus we examined the relationship between SVV and standing balance in 29 hemiparetic patients with a first-ever supratentorial stroke. We measured the rotation angle formed by a subjective vertical and the gravitational vertical (rotation to the non-paretic side was set as positive) 8 times, and employed the mean value as the SVV value. We also calculated the absolute rotation angle for each time and employed the mean value as the absolute SVV value. Then we evaluated postural balance using four stabilometer parameters : length of center of pressure per time (LNG/T), envelopment area (ENV), root mean square (RMS) and weight-bearing asymmetry (WBA) during standing. The relationship between the SVV values or the absolute SVV values and the four stabilometer parameters were analyzed using the Spearman's rank correlation coefficient. The mean values for SVV and absolute SVV of all participants were -0.3±2.3° and 2.0±1.5°, respectively. The absolute SVV value and each of the four parameters were positively correlated with statistical significance (LNG/T ; <i>r</i>=0.44, ENV ; <i>r</i>=0.41, RMS ; <i>r</i>=0.46, WBA ; <i>r</i>=0.40), while there was no statistically significant correlation between the SVV value and each of them. These results suggest that the SVV bias size is possibly related to standing balance in stroke patients.