Plantar cutaneous sensory stimulation improves single-limb support time, and EMG activation patterns among individuals with Parkinson's disease

Parkinson's disease is a chronic neurological disorder that results in gait and posture impairment. There is increasing evidence that these motor impairments may be partially due to deficits within the sensory system. In this study, the effects of a facilitatory insole that provides increased plantar sensory stimulation, was evaluated during gait, in a group of individuals with Parkinson's disease in comparison with healthy age-matched controls. Spatial–temporal parameters of gait were evaluated using an instrumented carpet, and muscle activation patterns were evaluated using surface EMG. All participants were tested with both a facilitatory (ribbed) insole and a conventional (flat) insole while walking 20 feet. Results indicated that the use of the facilitatory insole produced a significant increase in single-limb support time. Additionally, the muscle activation sequence of the tibialis anterior was normalized by the facilitatory insole, at the time of initial ground contact. These changes may lead to an overall improvement in gait pattern and stability, and suggest that the use of this type of facilitatory insole may be a useful treatment strategy for improving the gait of individuals with Parkinson's disease. This also provides support for the role of facilitation of the sensory system in improving motor output in individuals with Parkinson's disease.