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

Craven, Colm Tadhg Donal (2015) Development and evaluation of rehabilitation technologies for early-stage spinal cord injury. PhD thesis, University of Glasgow.

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 an increased neuromuscular response, and if
so, to characterise the magnitudes and trends of the responses.
Ten participants with no neurological deficit were recruited to investigate the feasibility
of WBV-pBWS and to establish a normative data set with which to compare the results
from 14 SCI participants recruited from QENSIU. The main factors under investigation were
vibration frequency, vibration amplitude, level of pBWS, muscle group and classification of
SCI. It was shown that WBV did elicit an increase in neuromuscular activity and that the
magnitude of the response could be moderated by vibration frequency, vibration amplitude
and level of pBWS. Average changes relative to baseline measurements were up to 71% for
the neurologically intact participants, and between 44% to 66% for the SCI participants
depending on classification of injury. Neuromuscular activity was characteristic for each
muscle group and the characteristic was principally moderated by the proximity of the muscle
to the WBV platform and peak platform acceleration. Despite the relatively large change
in neuromuscular activity when compared to baseline, the absolute changes in activity were
relatively small and likely to be of insufficient magnitude to result in muscle hypertrophy.
Results from this study indicated that WBV was of sufficient intensity to elicit a response
from the �-motoneuron but of insufficient intensity to increase muscle strength. Based on
this, the potential use of WBV as a non-pharmacological treatment of spasm was identified
by stimulating part of the neural pathway upon which spasm acts and therefore provide
a mechanism to moderate the threshold for spasm, without the risk of increasing muscle
strength and therefore potential for injury during a spastic episode.
In summary, this thesis presents RATTT and WBV-pBWS as two modalities suitable for
use in early-stage SCI rehabilitation. While RATTT can elicit substantial cardiopulmonary
responses in this patient group, the evaluation of WBV showed limited effects on muscle
activation, but suggested potential application in the treatment of spasticity.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Spinal cord injury, rehabilitation, whole body vibration, erigo, exercise, electromyography
• Subjects: T Technology > T Technology (General); T Technology > TA Engineering (General). Civil engineering (General); T Technology > TJ Mechanical engineering and machinery
• Colleges/Schools: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Supervisor's Name: Gollee, Dr. Henrik
• Date of Award: 2015
• Depositing User: Mr Colm Craven
• Unique ID: glathesis:2015-5898
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 29 Jan 2015 08:44
• Last Modified: 29 Jan 2015 14:47
• URI: https://theses.gla.ac.uk/id/eprint/5898