Determination of Optimal Conditions for Neuroprosthetic Functional Electrical Stimulation Therapy to Produce Wrist Dorsiflexion Movements Using the Versatility Index
Professor GUNMA PAZ UNIVERSITY Takasaki, Gumma, Japan
Research Objectives: To determine the optimal conditions for neuroprosthetic functional electrical stimulation therapy to produce repetitive ROM of 50% or more with minimal pain in the old paralyzed hand.
Design: Non-randomized, controlled experimental study comparing three conditions: 35 Hz, 70 Hz, and 120 Hz.The study will be conducted in accordance with the Design of Experiments method.
Setting: University laboratory and day care for the elderly.
Participants: Total 18 patients included. 7 healthy subjects and 11 hemiplegic patients in the life phase after stroke. Participation criteria At least 1 year after stroke onset Inability to achieve range of motion in finger extension completely on their own. Exclusion criteria Peripheral neuropathy, severe dementia.
Interventions: Low frequency square waves of 35 Hz and 70 and 120 Hz were energized using a Backyard Brains's Brain-Computer Interfaces(BCI) kit, which is switched on at a normal side myopotential threshold of 9-15 mv. The energization was performed 12 times. In normal subjects, switching was performed at the action potential of the dominant hand.
Main Outcome Measures: Maximal dorsiflexion angle of the wrist joint during energization, calculated from the sagittal plane video animation. Pain (Robert R. Edwards,Numerical rating scale:NRS) and versatility index (wrist dorsiflexion angle/pain) during energization.
Results: In ANOVA, wrist dorsiflexion angle was significantly greater at 120 Hz than at 35 Hz (p=.031, 95% CI -6.9138 to -0.2428) . Pain was significantly less at 35 Hz than at 70 Hz (p <.001,95%CI -2.2478 to -1.1739) and 120 Hz (p <.001,95%CI -2.5117 to -1.4378).No hemiplegic patient had a maximum versatility index at 35 Hz.
Conclusions: 120 Hz increased dorsiflexion angle, but was also suggested to increase pain. Few hemiplegics had a maximum versatility index at 35 Hz. It was suggested that 70 Hz was the optimal condition. Not only in Japan, a country with longevity but also in other developed countries, research should be conducted on the specific conditions under which assistive devices are effective in maintaining peripheral circulation in hemiplegic patients.
Author(s) Disclosures: No disclosures by the authors.
Learning Objectives:
Upon completion, participants will be able to describe neuroprosthetic electrical stimulation.
Upon completion, participants will be able to define Versatility Index.
Upon completion, participants will be able to describe the optimal conditions for neuroprosthetic electrical stimulation of hemiplegics who have been in the program for more than one year.
Upon completion, participants will be able to describe how they use experimental design in non-randomized trials.