Wide-pulse-width, high-frequency neuromuscular stimulation: implications for functional electrical stimulation
Open Access
- 1 July 2006
- journal article
- research article
- Published by American Physiological Society in Journal of Applied Physiology
- Vol. 101 (1) , 228-240
- https://doi.org/10.1152/japplphysiol.00871.2005
Abstract
Electrical stimulation (1-ms pulses, 100 Hz) produces more torque than expected from motor axon activation (extra contractions). This experiment investigates the most effective method of delivering this stimulation for neuromuscular electrical stimulation. Surface stimulation (1-ms pulses; 20 Hz for 2 s, 100 Hz for 2 s, 20 Hz for 3 s) was delivered to triceps surae and wrist flexors (muscle stimulation) and to median and tibial nerves (nerve stimulation) at two intensities. Contractions were evaluated for amplitude, consistency, and stability. Surface electromyograph was collected to assess how H-reflexes and M-waves contribute. In the triceps surae, muscle stimulation produced the largest absolute contractions (23% maximal voluntary contraction), evoked the largest extra contractions as torque increased by 412% after the 100-Hz stimulation, and was more consistent and stable compared with tibial nerve stimulation. Absolute and extra contraction amplitude, consistency, and stability of evoked wrist flexor torques were similar between stimulation types: torques reached 11% maximal voluntary contraction, and extra contractions increased torque by 161%. Extra contractions were 10 times larger in plantar flexors compared with wrist flexors with muscle stimulation but were similar with nerve stimulation. For triceps surae, H reflexes were 3.4 times larger than M waves during nerve stimulation, yet M waves were 15 times larger than H reflexes during muscle stimulation. M waves in the wrist flexors were larger than H reflexes during nerve (8.5 times) and muscle (18.5 times) stimulation. This is an initial step toward utilizing extra contractions for neuromuscular electrical stimulation and the first to demonstrate their presence in the wrist flexors.Keywords
This publication has 41 references indexed in Scilit:
- Contribution of M-Waves and H-Reflexes to Contractions Evoked by Tetanic Nerve Stimulation in HumansJournal of Neurophysiology, 2006
- Persistent inward currents in motoneuron dendrites: Implications for motor outputMuscle & Nerve, 2004
- Forces consistent with plateau-like behaviour of spinal neurons evoked in patients with spinal cord injuriesBrain, 2003
- Sustained Muscle Contractions Maintained by Autonomous Neuronal Activity Within the Human Spinal CordJournal of Neurophysiology, 2003
- Physiological Significance of Myosin Phosphorylation in Skeletal MuscleCanadian Journal of Applied Physiology, 1993
- Optimal stimulus duration for the H reflexMuscle & Nerve, 1989
- Nonlinear summation of contractions in striated muscle. II. Potentiation of intracellular Ca2+ movements in single barnacle muscle fibresJournal of Muscle Research and Cell Motility, 1986
- Discharge pattern of single motor units in the tonic vibration reflex of human triceps surae.Journal of Neurology, Neurosurgery & Psychiatry, 1976
- Contraction Times of Twitches Evoked by H‐ReflexesActa Physiologica Scandinavica, 1970
- Motoneuron activation by low intensity tetanic stimulation of muscle afferents in manExperimental Neurology, 1967