Endurance and postural control in people with chronic stroke. A pilot study.

Abstract

The risk of falling in people with chronic stroke represents a major public health problem. While many risk factors have been addressed, the relationship between endurance and balance deficits has not been investigated. This study examined the impact of diminished endurance on postural control in chronic stroke survivors. Eleven subjects were recruited (3 males; mean age=54.90(±12.29)years; mean post-stroke-time=44.63(±46.64)months). A Six-Minute Walk (6MW) test was performed to induce fatigue between two limits-of-stability (LOS) tests without rest. The 6MW distance, change in LOS completion time, and fatigue index (FI) were recorded. The mean 6MW distance was 914.09(±518.59)feet, the mean change in LOS-time was 8.63(±25.60)seconds, and the mean FI was 5.72(±2.00). Both 6MW distance and FI showed a strong correlation with LOS-time-change (r=-.703,p=.05; r=.799,p=.01). Our preliminary findings indicate that postural control can be affected by fatigue induced by distance walking, and there may be a relationship between endurance, fatigue, and postural control. Specifically, the better the endurance recorded, the less time delay was noted on the LOS test; while the greater the fatigue reported, the greater time delay was noted on the LOS test. Fatigue is a complex measure with muscular, cardiovascular, and psychological components. While the 6MW may not consistently induce the same fatigue level in every subject, our findings suggest a relationship between prolonged exercise and change in time required to perform LOS test. The relationship between aerobic fitness level, onset of fatigue, and balance in people post-stroke will require more sensitive tools in future investigations.