Article

A critical limitation with transcutaneous neuromuscular electrical
stimulation as a rehabilitative approach is the rapid onset of muscle fatigue
during repeated contractions. We have developed a method called spatially
distributed sequential stimulation (SDSS) to reduce muscle fatigue by distributing the center of electrical field over a wide area within a single
stimulation site, using an array of surface electrodes.
OBJECTIVE: To extend the
previous findings and to prove feasibility of the method by exploring the
fatigue-reducing ability of SDSS for lower limb muscle groups in the able-bodied
population, as well as in individuals with spinal cord injury (SCI). METHODS:
SDSS was delivered through 4 active electrodes applied to the knee extensors and
flexors, plantarflexors, and dorsiflexors, sending a stimulation pulse to each
electrode one after another with 90 degrees phase shift between successive
electrodes. Isometric ankle torque was measured during fatiguing stimulations
using SDSS and conventional single active electrode stimulation lasting 2
minutes. RESULTS: We demonstrated greater fatigue-reducing ability of SDSS
compared with the conventional protocol, as revealed by larger values of fatigue
index and/or torque peak mean in all muscles except knee flexors of able-bodied
individuals, and in all muscles tested in individuals with SCI. CONCLUSIONS: Our
study has revealed improvements in fatigue tolerance during transcutaneous
neuromuscular electrical stimulation using SDSS, a stimulation strategy that
alternates activation of subcompartments of muscles. The SDSS protocol can
provide greater stimulation times with less decrement in mechanical output
compared with the conventional protocol.
CI - (c) The Author(s) 2014.

Langue : ANGLAIS