Article

The aim of this study is to determine the impact of electrical
stimulation frequency on muscle force and fatigue and propose application
modalities in regards to sports or clinical rehabilitation training. METHODS: The maximal voluntary contraction (MVC) force of the quadriceps femoris muscle was
recorded before, during and after electrical stimulation in 26 healthy adults
during 20-minute sessions corresponding to 60 of 5-second contractions separated
by 15-second rest periods. Three different frequencies were used: 100, 50 and 20
Hz. RESULTS: With a frequency of 100 Hz, we obtained 71% of the MVC force at the
beginning of the session (MVCb). The decrease in muscle force at the end of the
session is significantly greater for the highest frequencies respectively 27, 33
and 38% of MVCb for 100, 50 and 20 Hz. CONCLUSION:
The impact of electrical
stimulation to improve muscle force seems to be dependent on frequency, intensity
pulse trains and number of contractions per session. Higher intensity and higher
frequency induce stronger muscular contractions, but also
a stronger decline in
force and thus quick-setting muscle fatigue. Classical 20-minute training
sessions with many contractions (60 or more) do not seem appropriate for sports
training or clinical rehabilitation programs.
CI - Copyright 2010 Elsevier Masson SAS. All rights reserved.

Langue : ANGLAIS ; FRANCAIS