A novel modulation strategy to increase stimulation duration in neuromuscular electrical stimulation

Muscle Nerve. 2011 Sep;44(3):382-7. doi: 10.1002/mus.22058.


Introduction: Neuromuscular electrical stimulation (NMES) has been shown to be an effective treatment for muscular dysfunction. Yet, a fundamental barrier to NMES treatments is the rapid onset of muscle fatigue. The purpose of this study is to examine the effect of feedback-based frequency modulation on the closed-loop performance of the quadriceps during repeated dynamic contractions.

Methods: In the first experiment, subjects completed four different frequency modulation NMES protocols utilizing the same amplitude modulation control to compare the successful run times (SRTs). A second experiment was performed to determine the change in muscle response to high- and low-frequency stimulation.

Results: Compared with constant-frequency stimulation, results indicate that using an error-driven strategy to vary the stimulation frequency during amplitude modulation increases the number of successful contractions during non-isometric conditions.

Conclusion: Simultaneous frequency and amplitude modulation increases the SRT during closed-loop NMES control.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Electric Stimulation
  • Electric Stimulation Therapy / methods*
  • Feedback, Physiological / physiology*
  • Female
  • Humans
  • Male
  • Muscle Contraction / physiology
  • Muscle Fatigue / physiology*
  • Neuromuscular Diseases / physiopathology
  • Neuromuscular Diseases / therapy*
  • Quadriceps Muscle / physiopathology
  • Task Performance and Analysis
  • Time Factors