Effect of abdominal binding on cardiorespiratory function in paralympic athletes with cervical spinal cord injury

Abstract

Spinal cord injury (SCI) causes a lesion-dependent impairment in cardiorespiratory function that may limit exercise capacity. The aims of this thesis were to describe cardiorespiratory function in highly-trained athletes with low-cervical SCI, and to investigate whether abdominal binding enhances cardiorespiratory function at rest and during exercise in this population. Using body plethysmography, bilateral phrenic nerve stimulation and transthoracic ultrasound, it was demonstrated that Paralympic athletes with cervical SCI exhibit a restrictive pulmonary defect, impaired diaphragm and expiratory muscle function, and low left ventricular mass and ejection fraction compared to able-bodied controls. Using the same methods, it was shown that abdominal binding improves resting cardiorespiratory function by reducing operating lung volumes, and increasing vital capacity, twitch transdiaphragmatic pressure, expiratory muscle strength and cardiac output. A further finding was a positive relationship between binder tightness and cardiorespiratory function. During a field-based assessment of fitness, abdominal binding reduced the time taken to complete an acceleration/deceleration test and increased the distance covered during a repeated maximal 4-min push test. During laboratory-based incremental wheelchair propulsion, abdominal binding altered breathing mechanics by reducing operating lung volumes and attenuating the rise in the pressure-time index of the diaphragm. Furthermore, abdominal binding increased peak oxygen uptake and reduced peak blood lactate concentration, despite no change in peak work rate. Peak oxygen uptake in the laboratory was related to the distance covered during the maximal 4-min push, suggesting that the improvement in field-based performance with binding was due to an improvement in aerobic capacity. In conclusion, this thesis demonstrates that abdominal binding significantly enhances cardiorespiratory function at rest, improves exercise performance in the field, and improves operating lung volumes, breathing mechanics and peak oxygen uptake during incremental treadmill exercise. Thus, abdominal binding provides a simple, easy-to-use tool that can be used to enhance cardiorespiratory function at rest and during exercise in highly-trained athletes with cervical SCI.