Chronic Effects of Wide-pulse Neuromuscular Electrostimulation on Neuromuscular and Functional Properties in Healthy Subjects
Condition: Healthy Volunteers
Study type: Interventional

Summary: 
      Neuromuscular electrostimulation (NMES) is a technique used in the clinical and training
      fields to increase the strength of a muscle group.The recent use of wide-pulse (WP)
      stimulations allows, in addition to the direct activation of the muscle fibers, the use of
      sensory pathways. This more global solicitation of the neuromuscular system (i.e. information
      going back to the spinal cord and even to the brain) prejudges more nervous adaptations and
      therefore a greater functional benefit. The first aim of this study is to evaluate and
      compare the force gains induced by 2 NMES training programs (CONV, WP) applied on knee
      extensors in healthy subjects for 6 weeks.The second aim is to understand the neuromuscular
      adaptations involved in these gains, as well as the functional benefit resulting from these
      improvements.
    

Detailed description: 
      Neuromuscular electrostimulation (NMES) is a technique used in the clinical and training
      fields to increase the strength of a muscle group. The conventional (CONV) parameters of NMES
      induces a direct activation of the muscle fibers located close to the stimulation electrodes.
      This means that the neuromuscular system is not fully solicited, which limits its adaptation.
      The recent use of wide-pulse (WP) stimulations allows, in addition to the direct activation
      of the muscle fibers, the use of sensory pathways. This more global solicitation of the
      neuromuscular system (i.e. information going back to the spinal cord and even to the brain)
      prejudges more nervous adaptations and therefore a greater functional benefit.

      The first aim of this study is to evaluate and compare the force gains induced by 2 NMES
      training programs (CONV, WP) applied on knee extensors in healthy subjects for 6 weeks. The
      second aim is to understand the neuromuscular adaptations involved in these gains, as well as
      the functional benefit resulting from these improvements. To consolidate the benefit of NMES
      programs, a control (CONT) modality is used as a reference and is representative of a
      sedentary behaviour regularly observed in our populations. The CONV modality allows us to
      compare with the current clinical application and the majority of the literature on the
      adaptations induced by NMES training. Finally, the WP modality aims to assess the possible
      benefits linked to the use of wide-pulses during the application of NMES. A clinical transfer
      will then be envisaged to confirm the interest and benefits of this type of program. We
      hypothesise that nervous adaptations will be increased by the use of WP NMES, leading to
      greater gains in strength and functional benefits than with CONV NMES.
    

Intervention name(s): Wide-pulse neuromuscular electrostimulation (WP NMES); Conventional neuromuscular electrostimulation (CONV NMES); Control (CONT) modality
Intervention type(s): Device; Device; Device
Intervention description(s): The WP NMES program consists of electrical stimulation trains of 1000 symmetrical biphasic pulses (1 ms, 100 Hz). The duration of a train is of 10 s and the rest between trains is of 30 s. A WP NMES session includes 30 evoked contractions. The stimulation intensity is monitored online and adjusted to the highest tolerable by the subjects.During the stimulation, subjects are seated with the knee joint fixed a 60° angle. Three self-adhesive electrodes are placed over the right thigh. The positive electrodes, measuring 25 cm² (5 x 5 cm), are placed as close as possible to the motor point of the vastus lateralis and vastus medialis muscles. The negative electrode, measuring 50 cm² (10 x 5 cm), is placed 5-7 cm below the inguinal ligament. Electrical stimulations are delivered by a stimulator BioStim (Mazet Santé).; The CONV NMES program consists of electrical stimulation trains of 500 symmetrical biphasic pulses (0.2 ms, 50 Hz). The duration of a train is of 10 s and the rest between trains is of 30 s (duty cycle: 1/3). A WP NMES session includes 30 evoked contractions. The stimulation intensity is monitored online and adjusted to the highest tolerable by the subjects.
During the stimulation, subjects are seated with the knee joint fixed a 60° angle. Three self-adhesive electrodes are placed over the right thigh. The positive electrodes, measuring 25 cm² (5 x 5 cm), are placed as close as possible to the motor point of the vastus lateralis and vastus medialis muscles. The negative electrode, measuring 50 cm² (10 x 5 cm), is placed 5-7 cm below the inguinal ligament. Electrical stimulations are delivered by a stimulator BioStim (Mazet Santé).; Control (CONT) modality is used as a reference and is representative of a sedentary behaviour regularly observed in our populations.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Evaluating and comparing the force gains induced by 2 NMES training programs (CONV, WP) applied on knee extensors in healthy subjects for 6 weeks. Understanding the neuromuscular adaptations involved in these gains, as well as the functional benefit resulting from these improvements. To consolidate the benefit of NMES programs, a control (CONT) modality is used as a reference and is representative of a sedentary behaviour regularly observed in our populations. The CONV modality allows us to compare with the current clinical application and the majority of the literature on the adaptations induced by NMES training. Finally, the WP modality aims to assess the possible benefits linked to the use of wide-pulses during the application of NMES.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Wide-pulse; Training; Strength gain; Neuromuscular adaptations; Neuromuscular electrostimulation