Article

A fundamental barrier to using electrical stimulation in the clinical setting is
an inability to maintain torque production secondary to muscle fatigue.
Electrical stimulation parameters are manipulated to influence muscle torque
production, and they may also influence fatigability during repetitive
stimulation. Our purpose was to determine the response of the quadriceps femoris
to three different fatigue protocols using the same initial torque obtained by
altering stimulator parameter settings. Participants underwent fatigue protocols
in which either pulse frequency (lowHz), pulse duration (lowPD), or voltage
(lowV) was manipulated to obtain an initial torque that equaled 25% of maximum
voluntary isometric contraction. Muscle soreness was reported on a visual analog
scale 48 h after each fatigue test. The lowHz protocol resulted in the least
fatigue (25% +/- 14%); the lowPD (50% +/- 13%) and lowV (48% +/- 14%) protocols
had similar levels of fatigue. The lowHz protocol resulted in significantly less
muscle soreness than the higher frequency protocols. Stimulation protocols that
use a lower frequency coupled with long pulse durations and high voltages result
in lesser amounts of muscle fatigue and perceived soreness. The identification of
optimal stimulation patterns to maximize muscle performance will reduce the
effect of muscle fatigue and potentially improve clinical efficacy.

Langue : ANGLAIS