The Influence of Plantar Cutaneous Stimulation on a Functional Test of Gait in Parkinson’s Disease

Although possible deficits in proprioception have been implicated as a cause of gait impairments in individuals with Parkinson’s disease (PD), little research has been done to investigate improving this possible deficit as a method to influence mobility. The overall purpose of the current thesis was to investigate the influence of increased plantar stimulation on stability and gait impairments. This study also investigated the contribution of attention to locomotion in PD. The two studies comprising this thesis addressed the possible influence of the ribbed insoles in the initial response of PD participants as well as the long-term use of the insole. The first study focused on developing a task to assess the influence of the facilitatory insoles on gait for individuals with PD compared to healthy control participants. For the purpose of evaluating the facilitatory insoles in a functionally relevant task participants performed a modified “Timed Up and Go” task with an additional secondary motor task. The secondary task of carrying a tray with glasses demonstrated that attention plays a large role in the production and maintenance of gait as gait deficits became more pronounced. However, the facilitatory insoles also influenced gait parameters which demonstrated that the possible deficits in proprioception contribute to the gait impairments in PD. The initial response to the insoles, in the first study, did not improve gait parameters, which suggests that PD participants may need more time to adjust to the increased plantar stimulation. The second study investigated the influence of the facilitatory insoles when they are worn for a longer period of time. Participants wore either the facilitatory insoles or blank insoles while completing the PD Sensory Attention Focussed Exercise (PD SAFEx) rehabilitation program. Results demonstrated that when the facilitatory insoles are worn long-term, they can benefit the turning and straight-line walking in individuals with PD. PD participants became more confident in their ability to turn as they exerted less control over their centre of mass. Participants also displayed a decreased base of support and time spent in double limb support without negatively affecting lateral stability. These improvements suggest that the facilitatory insoles, when worn long-term, allow for a more normalized pattern of gait for individuals with PD. The TUG task used in this thesis proved to be a good measure to evaluate changes in stability and gait parameters in PD participants. Long-term use of the facilitatory insoles demonstrated improvements in stability and gait deficits during difficult aspects of gait such as turning. This suggests that the facilitatory insoles would be a simple and effective intervention to use, however further investigation should occur to ensure that the improvements will continue when facilitatory insoles are used on a daily basis. As well, investigation into the long-term use of other types of cutaneous stimulation such as vibratory insoles would be beneficial for the PD population