Self-paced treadmill as a rehabilitation tool for recovering functional gait in people with stroke

  • Eunice Dorilia Ibala

Student thesis: Doctoral Thesis

Abstract

Background. The underlying mechanism operating during the rehabilitation of walking after a stroke is not fully understood. Treadmill training is a rehabilitation tool used to improve the walking capacity of people affected by stroke with evidence of improvement to fitness and walking speed. These changes are not, however, translated to improved ability or participation in community walking which is an important goal of rehabilitation. When combined with an immersive virtual reality environment, self-paced treadmill (in which the belt speed automatically adapts to the user's intended speed) training can be used to simulate an overground community walking experience with the potential to train more complex walking skills such as speed adaptation, obstacle avoidance and dual tasking which are essential components of successful independent community walking. The electrical activity of muscles (electromyograms) can reveal the underlying motor control strategy employed when walking in different contexts, for example indoors or community walking. Mathematical tools such as the variance ratio and the occurrence frequency provide a means of quantifying this muscle activity including variability and phasic activity. These tools may help to understand the potential of walking simulators (self-pacing treadmills synchronised with virtual reality) as tools in the rehabilitation of community mobility following stroke.;Methods. Two studies were conducted; an initial study to explore the motor control and biomechanical differences across overground, standard (fixed pace) treadmill and self-paced treadmill walking in able-bodied adults and a second study further exploring these differences in a post stroke population and including outdoor and gradient walking. Data collection for both studies included EMG and kinematic data during treadmill (standard and self-pacing), indoor and outdoor gait of varying speeds and gradients and required the development of bespoke software and novel algorithms to identify the underlying differences in motor control and muscle activity variability in particular. Results. Using the variance ratio, self-paced (SP) treadmill walking and overground outdoor walking presented similar value during level walking for both the able-bodied and stroke participants. Variance ratio values during self-paced treadmill walking ranged from 0.36 to 0.51, and from 0.38 to 0.77 during outdoor walking. A variance ratio value close to 1 represents low repeatability of the muscle pattern. The results suggest that SP treadmill walking, which allows natural speed variability, is a closer analogue to outdoor walking, in terms of muscle activation consistency, than fixed pace treadmill walking. For the able-bodied participants, fixed pace treadmill walking and indoor presented similar low VR values (0.26 and 0.22 respectively), which indicated a highly repeatable (cycle to cycle) EMG patterns.;Discussion. It was found that it is possible to use quantitative measures of EMG variability to characterise the differences of muscle recruitment strategies between different walking situations such as treadmill walking at a fixed pace, treadmill walking in self-pace and overground walking indoors and outdoors. The self-paced treadmill walking and overground outdoor situations presented the most similarities in muscle activity variability. The number of participants, especially stroke survivors (n=2) was limited and cannot be generalised. Nonetheless, the use of self-paced treadmills coupled with an immersive virtual environment and, targeting community walking training present a promising platform for gait adaptability training. Conclusion. The use of the self-paced treadmills within an immersive virtual environment, present similarities to outdoor walking. Using these treadmills as
Date of Award2 Feb 2021
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SponsorsUniversity of Strathclyde
SupervisorAndy Kerr (Supervisor) & Sylvie Coupaud (Supervisor)

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