Physiological adaptations to exercise in people with spinal cord injury

Abstract

The number of patients that suffer some type of spinal cord lesion in recent years are high and have increased because of factors such as traffic accidents. Although their life expectancy has increased, cardiovascular illnesses is one of the main causes of morbidity and mortality. Since the degree of physical fitness is an important factor regarding the risk of cardiovascular disease, the objective of the present study was to examine the global adaptation (cardiorespiratory, metabolic and thermoregulatory response) of the organism to exercise and the application of this data to the habitual practice of physical activity to improve state of health. A group of 42 patients with spinal injury, 85% of whom were paraplegic and the remaining 15% tetraplegic performed 42 exercise tests on a cycloergometer. Body temperature (tympanum, surface of the deltoids and surface of the back), metabolic parameters (plasma uric acid, glycemia, plasma lactate), cardiocirculatory adaptation (heart rate, blood pressure arm, blood pressure leg) and ventilatory adaptation (VO2, VCO2, fr Vt, VE) were monitored. Blood pressure in the arm, blood concentrations of lactate and ventilatory parameters showed an evolution statistically dependent on the work to which the subject was submitted. Heart rate showed a statistically significant correlation with the ventilatory parameters and work load. The proportional response of the cardioventilatory parameters to the increase in the work load allowed us to evaluate the repercussion of a given exercise and thus avoid exercise of an excessive intensity that could produce cardiocirculatory changes that might entail an added risk. Heart rate presents an excellent correlation, shown in this work, with the oxygen consumption and could therefore be used to quantify the cardiorespiratory and metabolic repercussion of the exercise carried out. Furthermore, this quantification may allow for the adaptation of exercise intensity to the patient thus improving the results obtained from the practice of exercise that has been proven so necessary in these patients.

Physical activity outside of structured therapy during inpatient spinal cord injury rehabilitation

“…Notably, our data shows that individuals perceive that they are engaged in moderate and heavy intensity activity for a median 20 to 28 min outside of physical and occupational therapy. However, the biggest contributor of this time is the median 7 to 10 min of higher intensity ADLs, and previous research shows that ADLs do not adequately challenge cardiovascular fitness in persons with SCI [4, 34, 35]. This is likely due to the nature of ADLs; they occur most often in very short bouts.…”

Time-courses of lung function and respiratory muscle pressure generating capacity after spinal cord injury: A prospective cohort study

“…There are several factors that change over time after an acute SCI, such as changes in muscle tone, spasticity, a lower chest wall and a higher abdominal compliance (26). Furthermore, factors such as postural changes, trunk stabilization and changes in physical activity levels are known to influence respiratory function and may therefore also influence trajectories of respiratory function (27)(28)(29). Increasing spasticity and chest wall stiffness occur over time in subjects with SCI (26).…”

Spectral Analyses of Cardiovascular Control in Rodents with Spinal Cord Injury

“…Autonomic dysreflexia (AD) and profound blood pressure (BP) increases following sensory stimulation below the lesion can be distressing and life-threatening . Both OH and AD negatively impact physical activity (Claydon et al, 2006a;Drory et al, 1990;Hol et al, 2007;Vidal et al, 2003), limiting rehabilitation. AD, OH and ''silent'' cardiac ischemia (Bauman et al, 1994) are all thought to contribute to increased severity of cardiovascular disease in SCI patients, which not only occurs earlier and progresses more rapidly than in the able-bodied (Imai et al, 2004;Whiteneck et al, 1992), but also is the leading cause of morbidity and mortality after SCI (Garshick et al, 2005;Myers et al, 2007).…”