Development and evaluation of rehabilitation technologies for early-stage spinal cord injury

Abstract

Exercise is fundamental to a return to normal living after a Spinal Cord Injury (SCI) but is complicated by a rapid decline in function and fitness immediately following the injury. In addition to muscle paralysis, Orthostatic Hypotension (OH), a decline in cardiopulmonary and vascular fitness, extensive muscle atrophy and bone demineralization each contribute to an inability to carry out effective forms of exercise. Suitable rehabilitation technologies are central to overcoming these complications and to facilitate recovery. The aim of the work presented in this thesis was to identify technologies which may be used for exercise during SCI rehabilitation, with a focus on early-stage SCI patients at the beginning of the rehabilitation process. Two such technologies were identified and investigated: Robotic Assisted Tilt Table Therapy (RATTT) and Whole Body Vibration (WBV). The suitability of these technologies was evaluated by measuring the acute physiological responses of SCI patients during intensive use of these systems. Robotic Assisted Tilt Table Therapy is primarily used to treat OH in stroke and SCI patients. However, the potential therapeutic effect of RATTT as an exercise modality has so far not been investigated. An investigation into the physiological responses of early-stage SCI patients during intensive RATTT stepping was therefore carried out. The intention was to determine whether RATTT may potentially be used for the combined purpose of increasing orthostatic tolerance, improving cardiopulmonary fitness and improving vascular health. RATTT is particularly suited to early-stage rehabilitation because orthostatic tolerance is not a prerequisite for its use. Three motor-complete and three motor-incomplete early- stage SCI patients were recruited from the Queen Elizabeth National Spinal Injuries Unit (QENSIU) in Glasgow to participate in this cross-sectional study. The cardiopulmonary and vascular responses to different RATTT stepping conditions, including the combination of RATTT stepping with Functional Electrical Stimulation (FES), were investigated. Increases in oxygen uptake, respiratory exchange ratio, minute ventilation and heart rate were found for both motor-incomplete and motor-complete SCI participants. The responses were largest for the motor-incomplete volunteers with Metabolic Equivalent (MET) values between 1.5 - 3.1. These results confirmed that RATTT can be used as an exercise modality during early- stage SCI rehabilitation. Whole Body Vibration was initially developed and commercialised for application during exercise in a general population with no neurological deficit, and while the physiological mechanisms which underly the response to WBV are still relatively poorly understood, current research suggests that WBV may lead to increases in muscle strength, power, bone mineral density and flexibility. It is hypothesised that the neuromuscular response to WBV is achieved through reflex activity, though the specific neural pathway is broadly debated. Nonetheless, an increase in neuromuscular activity duringWBV has been confirmed, suggesting that it may potentially be used to increase muscle mass, strength and power, and therefore counteract muscle atrophy and bone demineralization in SCI. However, little is known about the neuromuscular response of SCI patients to WBV, and it is not clear how to best administer WBV to this patient group or which vibration parameters should be applied. A WBV platform was therefore integrated with a partial Body Weight Support (pBWS) system in order to investigate the application of WBV during SCI rehabilitation. The feasibility of this approach was determined in the first instance in experiments with participants from a general population with no neurological deficit, followed by an evaluation with a SCI population. The aim was to determine if the stimulus from WBV applied in conjunction with pBWS was sufficient to elicit a