Lauren Rietchel and Victoria Claydon
This is a summary of an original research article assessing the impact of low blood pressure and low exercising heart rates on physical activity and participation after spinal cord injury (SCI).
To read the original article, please click here.
Why study physical activity and participation?
High-level SCI can cause damage to nerves that regulate the cardiovascular system, making it hard for affected individuals to regulate their heart rate and blood pressure. As a consequence, blood pressure can be very low in people with high-level SCI, and their heart rates are often slow and fail to increase as they should during exercise. This might make it harder for these individuals to participate in society or undertake physical activity.
This study aimed to determine whether the presence of low blood pressure and low peak exercise heart rates in people with SCI are associated with reduced physical activity and participation in society. Resting blood pressure and peak exercise heart rates (the highest heart rate during wheeling exercise to exhaustion) were measured in individuals who had recently sustained a SCI, at the time they were discharged from hospital. These values were then related to physical activity and participation levels 1-year and 5-years later.
What did the researchers find?
Individuals with a low peak exercise heart rate at discharge were more likely to have high-level SCI and to need a longer hospital stay after injury. Those with low peak exercise heart rates also had poorer participation in society after 1-year. Even when other personal factors were considered that might influence participation (such as the level and type of SCI sustained, their participation levels before they were injured, the length of time spent in hospital after injury, or the persons’ age or sex) those with lower peak exercise heart rates continued to have poorer participation. This was also the case after 5-years, but not when the other personal factors were taken into consideration. Individuals with low peak heart rate also had lower physical activity levels after 1-year and 5-years, but again, not when other factors were considered. Low blood pressure was not related to participation or physical activity levels 1-year or 5-years after discharge.
What do the findings suggest?
Individuals with SCI and low peak heart rates at discharge from hospital have more severe injury to the nerves that control the heart and blood pressure. These individuals are less likely to participate in society during their early rehabilitation after injury. These data suggest that peak heart rate during exercise measured at discharge from rehabilitation after SCI should be used to identify those needing additional support to facilitate their physical activity and participation in society after discharge. Those with low peak exercise heart rate and a longer hospital stay seem to be at particular risk and should be targeted for additional support when transitioning to the home environment.