Cardiovascular disease risk and central and peripheral responses to exercise in individuals with spinal cord injury

Introduction: Persons with spinal cord injury (SCI) are often physically inactive and as such are at increased risk of cardiovascular morbidity. Fortunately, exercise training in SCI can provide improve health-related physical fitness and alleviate medical complications associated with deconditioning. To optimize health-related fitness gains of exercise in SCI and maximize the potential for chronic disease prevention it is necessary to understand the acute responses (central and peripheral) to exercise. Purposes: The primary purposes of this research were to: 1) determine the contribution of central/peripheral limitations to exercise capacity and 2) examine vascular health in SCI. Methods: Seven persons with paraplegia and seven able-bodied (AB) individuals participated in two testing days. Testing day one consisted of incremental arm crank ergometry to exhaustion with measures of cardiac output, muscle oxygenation, and expired gas and ventilatory parameters. Testing day two involved the measurement of arterial compliance and endothelial function. Results: There was a significant difference for small artery compliance between SCI and AB(6.9±3.7 versus 10.5±1.7ml mmHg⁻¹x100, p< 0.05). Arm total haemoglobin increased significantly throughout exercise. Arm oxygenation decreased until 60% of maximal wattage after which values did not change. Though non-significant, the large effect size (eta²=.142) suggests a trend for higher aerobic power in AB (28.6±5.7mL.kg⁻¹min-1)than in SCI (23.7±2.77mL.kg⁻¹min⁻¹)due to a trend for higher cardiac output values in AB (18.0±5.7L.min⁻¹)than SCI (15.8±3.4L.min⁻¹)at maximal exercise. Conclusions: Small artery compliance is lower in SCI than AB. Leveling off of deoxygenated haemoglobin with total haemoglobin increasing throughout exercise suggests a peripheral limitation to arm ergometry in both groups. A trend for higher cardiac output in AB suggests a central limitation in SCI.Education, Faculty ofKinesiology, School ofGraduat

Physical activity during inpatient spinal cord injury rehabilitation

Introduction Rehabilitation activities of a sufficient intensity are necessary for optimal recovery in individuals with spinal cord injury (SCI). Optimizing rehabilitation and activity prescription requires quantification of physical activity and its predictors during this time. Purpose To determine, during inpatient rehabilitation, the: 1) reliability and validity of measures of physical activity. 2) level of physical activity using objective and self-report measures. 3) level of cardiovascular stress experienced during physical therapy (PT) and occupational therapy (OT). 4) variables associated with greater time spent at higher heart rate during PT. 5) number of active movement repetitions occurring during PT and OT. Methods Design: A test retest design was used to determine the reliability of physical activity measures. A longitudinal observation design was used to determine movement repetitions and physical activity levels. A cross-sectional observational design was used to determine the level of cardiovascular stress. Subjects: Participants (n=108) were recruited from consecutive admissions to rehabilitation. Results Good reliability for accelerometry and step counts, and moderate reliability for self-report, was demonstrated. Validity was demonstrated for wrist accelerometry and step counts but not self-report physical activity. For most groups and variables, no changes occurred during therapy time from admission to discharge. Outside of therapy all groups increased from admission to discharge in accelerometer measured activity kilocounts but not self-report minutes, where the majority of time was spent in leisure time sedentary activity (~4.5 hours). The average time spent at a heart rate within the cardiovascular training zone was 6.0±9.0 minutes in PT and lower in OT. Lower spasticity, higher exercise self-efficacy, and better orthostatic tolerance correlated with a greater amount of time within a cardiovascular training zone. Average repetitions for PT and OT combined did not exceed 300 for the upper or lower extremity. Most repetition variables remained unchanged over the inpatient rehabilitation stay while clinical outcomes improved significantly. Conclusions Individuals report that a large amount of time is spent engaged in higher intensity activities. Measurement of heart rate during therapy sessions shows little time is spent at intensities sufficient to accrue cardiovascular benefits. Repetitions in therapy are low compared to the motor learning literature.Medicine, Faculty ofGraduat

Reliability and validity of daily physical activity measures during inpatient spinal cord injury rehabilitation

Objectives: To assess the test–retest reliability and convergent validity of daily physical activity measures during inpatient spinal cord injury rehabilitation. Design: Observational study. Setting: Two inpatient spinal cord injury rehabilitation centres. Subjects: Participants ( n  = 106) were recruited from consecutive admissions to rehabilitation. Methods: Physical activity during inpatient spinal cord injury rehabilitation stay was recorded on two days via (1) wrist accelerometer, (2) hip accelerometer if ambulatory, and (3) self-report (Physical Activity Recall Assessment for People with Spinal Cord Injury questionnaire). Spearman’s correlations and Bland–Altman plots were utilized for test–retest reliability. Correlations between physical activity measures and clinical measures (functional independence, hand function, and ambulation) were performed. Results: Correlations for physical activity measures between Day 1 and Day 2 were moderate to high (ρ = 0.53–0.89). Bland–Altman plots showed minimal bias and more within-subject differences in more active individuals and wide limits of agreement. None of these three physical activity measures correlated with one another. A moderate correlation was found between wrist accelerometry counts and grip strength (ρ = 0.58) and between step counts and measures of ambulation (ρ = 0.62). Functional independence was related to wrist accelerometry (ρ = 0.70) and step counts (ρ = 0.56), but not with self-report. Conclusion: The test–retest reliability and convergent validity of the instrumented measures suggest that wrist and hip accelerometers are appropriate tools for use in research studies of daily physical activity in the spinal cord injury rehabilitation setting but are too variable for individual use

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

Background: Little information exists on the content of inpatient rehabilitation stay when individuals with spinal cord injury (SCI) are not engaged in structured rehabilitation therapy sessions. Investigation of inpatient therapy content is incomplete without the context of activities outside of this time. We sought to quantify physical activity occurring outside of physical therapy (PT) and occupational therapy (OT) sessions during inpatient SCI rehabilitation and examine how this activity changes over time from admission to discharge. Methods: In this longitudinal observational study at two inpatient SCI rehabilitation centres, 95 participants were recruited through consecutive admissions. Physical activity at admission and discharge was recorded by 1) self-report (PARA-SCI questionnaire) and 2) real-time accelerometers worn on the dominant wrist, and hip if ambulatory. For analyses, we separated participants into those with paraplegia or tetraplegia, and a subgroup of those ambulatory at discharge. Wilcoxon signed rank tests (admission vs. discharge) were used for PARA-SCI minutes and accelerometry activity kilocounts. Results: There was no change in self-report physical activity, where the majority of time was spent in leisure time sedentary activity (~4 h) and leisure time physical activity at a higher intensity had a median value of 0 min. In contrast, significant increases in physical activity outside PT and OT sessions from admission to discharge were found for wrist accelerometers for individuals with tetraplegia (i.e., upper limb activity) and hip accelerometers for ambulatory individuals (i.e., walking activity). Conclusion: Physical activity is low in the inpatient SCI rehabilitation setting outside of structured therapy with a substantial amount of time spent in leisure time sedentary activity. Individuals appear to have the capacity to increase their levels of physical activity over the inpatient stay.Medicine, Faculty ofOther UBCNon UBCMedicine, Department ofOccupational Science and Occupational Therapy, Department ofPhysical Medicine and Rehabilitation, Division ofPhysical Therapy, Department ofReviewedFacult

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

Abstract Background Little information exists on the content of inpatient rehabilitation stay when individuals with spinal cord injury (SCI) are not engaged in structured rehabilitation therapy sessions. Investigation of inpatient therapy content is incomplete without the context of activities outside of this time. We sought to quantify physical activity occurring outside of physical therapy (PT) and occupational therapy (OT) sessions during inpatient SCI rehabilitation and examine how this activity changes over time from admission to discharge. Methods In this longitudinal observational study at two inpatient SCI rehabilitation centres, 95 participants were recruited through consecutive admissions. Physical activity at admission and discharge was recorded by 1) self-report (PARA-SCI questionnaire) and 2) real-time accelerometers worn on the dominant wrist, and hip if ambulatory. For analyses, we separated participants into those with paraplegia or tetraplegia, and a subgroup of those ambulatory at discharge. Wilcoxon signed rank tests (admission vs. discharge) were used for PARA-SCI minutes and accelerometry activity kilocounts. Results There was no change in self-report physical activity, where the majority of time was spent in leisure time sedentary activity (~4 h) and leisure time physical activity at a higher intensity had a median value of 0 min. In contrast, significant increases in physical activity outside PT and OT sessions from admission to discharge were found for wrist accelerometers for individuals with tetraplegia (i.e., upper limb activity) and hip accelerometers for ambulatory individuals (i.e., walking activity). Conclusion Physical activity is low in the inpatient SCI rehabilitation setting outside of structured therapy with a substantial amount of time spent in leisure time sedentary activity. Individuals appear to have the capacity to increase their levels of physical activity over the inpatient stay