The neuromuscular electrical stimulation (NMES) parameters that optimally modulate torque output during prolonged stimulation protocols are not well-established. The purpose of this study was to compare torque output between low-frequency and high-frequency NMES protocols while increasing stimulation intensity. Eleven healthy young individuals received a repetitive, intermittent low-frequency (20 Hz) and high-frequency (60 Hz) NMES over the quadriceps muscles. Stimulation intensity was increased throughout the protocol to achieve a submaximal target torque output. Mean torque, peak torque and torque-time integral (TTI) were measured. The 20 Hz protocol produced a higher mean torque (P = 0.001) and TTI (P = 0.008) compared to the 60 Hz protocol. The stimulation intensity required to achieve target torque during NMES was not different between frequencies (P > 0.0001). When the goal is to optimize torque output during prolonged submaximal NMES, such as during functional electrical stimulation, low-frequency stimulation may be preferred.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jelekin.2018.06.007 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Design and analysis of electromagnetic and mechanical structure of ultra-high-speed slotted solid rotor induction motor.
Sci Rep
January 2025
The School of Electrical Engineering, Guangxi University, Nanning, 530004, China.
In this paper, a high speed slotted solid-rotor induction motor (SSRIM) with rated power of 15 kW and rated speed of 120krpm is studied, and its electromagnetic performance and rotor mechanical structure are optimized. First, according to the empirical formula of motor design, the volume size of the motor is determined. Then, by constructing a two-dimensional finite element model, the slot matching scheme and coil pitch are optimized, and the influence of different slot matching scheme and coil pitch on the output torque and harmonics of the motor is compared.
View Article and Find Full Text PDFWithout visual feedback voluntary torque is overestimated during muscle potentiation despite similar motor unit firing rate and perception of exertion.
J Neurophysiol
January 2025
School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, ON, Canada.
The purpose was to assess whether visual feedback of torque contributes to motor unit (MU) firing rate reduction observed during post-activation potentiation (PAP) of skeletal muscle. From 15 participants 23 MUs were recorded with intramuscular fine-wire electrodes from the tibialis anterior during isometric dorsiflexion contractions at 20% of maximum, with and without both PAP and visual feedback of torque. A 5s maximal voluntary contraction (MVC) was used to induce PAP, and evoked twitch responses were assessed before and after.
View Article and Find Full Text PDFEffects of forearm rotation on wrist flexor and extensor muscle activities.
J Orthop Surg Res
January 2025
Department of Orthopedic Surgery, Tokyo Medical University Ibaraki Medical Center, Ami-Town, Ibaraki-Pref., Japan.
The forearm muscles coordinately control wrist motion, and their activity is affected by forearm rotation. Although forearm rotation has been implicated in the development of lateral and medial epicondylitis, its biomechanical background remains unknown. Therefore, the present study investigated the activity of wrist muscles in various forearm positions.
View Article and Find Full Text PDFKnee position affects medial gastrocnemius and soleus activation during dynamic plantarflexion: no evidence for an inter-muscle compensation in healthy young adults.
Biol Open
December 2024
Department of Kinesiology, Hungarian University of Sports Sciences, Alkotás utca 44-48, Budapest 1123, Hungary.
Knee joint position influences ankle torque, but it is unclear whether the soleus compensates to counteract the reductions in gastrocnemius output during knee-flexed versus knee-extended plantarflexions. Therefore, the purpose of this study was to determine the effects of knee joint position and plantarflexion contraction velocity on ankle plantarflexion torque and electromyography activity of the medial gastrocnemius and soleus in healthy young adults. Healthy male participants (n=30) performed concentric plantar flexions in a custom-built dynamometer from 15° dorsiflexion to 30° plantarflexion at gradually increasing velocities during each contraction at 30, 60, 120, 180, and 210° s-1 in a supine position with the knee fully extended and while kneeling with the knee fixed in 90° flexion.
View Article and Find Full Text PDFModeling and dynamic analysis of split torsion transmission system considering backlash and center distance errors.
Sci Rep
January 2025
National Key Laboratory of Science and Technology on Helicopter Transmission, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
The split torque gear transmission holds significant potential for use in helicopter main reducer transmission systems due to its benefits of low noise, high power-to-weight ratio, and high reliability. In this context, a nonlinear dynamic equation was formulated in the present study for a single-input dual-output gear split-torque transmission system, and the system's dynamic behavior was examined under the effects of center distance error and backlash using the fourth-order Runge-Kutta method. The findings indicate that the impact of center distance error on the system's dynamics is linear, whereas the effect of backlash is nonlinear.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!