Strength Response in Human Quadriceps Femoris Muscle During 2 Neuromuscular Electrical Stimulation Programs

Abstract

Study Design: Experimental mixed repeated-measures design. Objective: To determine the effect of 2 versus 3 neuromuscular electrical stimulation (NMES) training sessions per week on the response to strength training of the quadriceps femoris muscle. Background: Many studies have examined the influence of training intensity (percent maximal voluntary isometric contraction [MVIC]) during NMES on the strength response of the quadriceps femoris muscle. However, no study has examined the effects of the number of NMES sessions per week on the change in strength of the quadriceps femoris. Methods and Measures: Twenty-seven healthy subjects (mean age ± SD, 23.2 ± 3.2 years) volunteered for the study and were randomly assigned to 1 of 3 groups; control group (no electrical stimulation); group 2 (NMES 2 times per week); and group 3 (NMES 3 times per week). Groups 2 and 3 received NMES (10 minutes per session) over a 4-week period for a total of 8 and 12 NMES training sessions, respectively. The isometric quadriceps femoris muscle force produced during NMES was monitored during each treatment minute. The MVIC force of the quadriceps femoris was assessed prior to the first week and at the start of weeks 2, 3, and 4 of the 4-week training program, with a final measurement after the fourth week (5 total measurements) for all subjects. Results: Only the mean percent change in quadriceps MVIC before and after the 4 weeks of training with NMES between the control group and group 3 was significantly different (P = .021). Conclusions: Based on the electrical stimulation parameters and healthy subjects used in this study, NMES caused significant increases in the quadriceps femoris muscle strength when used for 3 training sessions per week for 4 weeks. It is possible that the use of a different electrical stimulation paradigm and/or a different patient population may result in strength gains with 1 or 2 sessions per week.

Efecto del entrenamiento combinado de pliometría y electroestimulación en salto vertical. (Effect of combined plyometric and electrostimulation training on vertical jump).

“…Por la similitud del EE NM con dichos entrenamientos, resultaría complicado realizar sesiones de EE NM diarias tal y como establecieron Ward y Shkuratova (2002) y Cigdem, Ozlen, Aylin, y Elif (2002. Dentro de cada sesión de entrenamiento, y respecto al tiempo total de aplicación, parece existir mayor consenso, estableciéndose tiempos de entre 10 y 15 minutos en la mayoría de los autores (Ward y Shkuratova, 2002;Parker, Bennet, Hieb, Hollar, y Roe, 2003;Brocherie et al, 2005;Babult et al, 2007).…”

Torque Responses in Human Quadriceps to Burst-Modulated Alternating Current at 3 Carrier Frequencies

“…For both the MVIC and EIT measurements of the quadriceps femoris muscle, the subjects were secured in a modified testing chair, as described by Parker et al 9 The MVIC and electrically induced forces were monitored through a belt attached to an SM-250 electronic load cell (Interface, Inc, Scottsdale, AZ). The belt was positioned 90°to the load cell during all measurements and was oriented perpendicular to the leg.…”

“…The proximal electrode was placed transversely over the point where the rectus femoris and vastus lateralis come together proximally. 9 Prior to the delivery of the 5 trains of NMES, the current amplitude needed to produce a fused contraction of the right quadriceps femoris was determined during 3 electrically induced muscle contractions. These initial electrically induced contractions also served to familiarize each subject to the sensation of NMES.…”

“…Biphasic asymmetrical spikes 4 and sinusoidal polyphasic waveforms 2,3,6,7,9,10,12 have been documented to result in significant muscle strength gains when used for NMES. These waveforms were delivered using either interrupted pulsed current or burst-modulated alternating current.…”

“…Quadriceps femoris muscular strength increases of 14.0% to 48.5% have been measured in subjects who received NMES for 4 to 5 weeks at 3 times per week. [2][3][4]6,7,9,10,12 For example, Selkowitz 10 utilized a training intensity of 91% of the maximal voluntary isometric contraction (MVIC) force and measured a 44% increase in quadriceps femoris muscle strength. Lai et al 4 studied the effects of NMES training at 25%…”