Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2024 Oct;12(20):e70039.
doi: 10.14814/phy2.70039.

Influence of kilohertz frequency, burst duty cycle and burst duration on evoked torque, discomfort and muscle efficiency: A randomized crossover trial

Karenina Arrais Guida Modesto  1 , Priscila Karen Silva Raposo  2 , Isabella da Silva Almeida  1 , Marco Aurélio Vaz  3 , João Luiz Quagliotti Durigan  4
Affiliations
Randomized Controlled Trial

Influence of kilohertz frequency, burst duty cycle and burst duration on evoked torque, discomfort and muscle efficiency: A randomized crossover trial

Karenina Arrais Guida Modesto et al. Physiol Rep. 2024 Oct.

Abstract

Kilohertz-frequency alternating currents (KFACs) have been indicated to minimize muscle atrophy and weakness. However, the optimal stimulation parameters still need to be determined.

Objective: This study aimed to investigate the effects of different KFACs on evoked torque, current efficiency, and perceived discomfort.

Design: KFACs with frequencies of 1 kHz (Aussie current) and 2.5 kHz (Russian current), along with two duty cycles (10% and 20%), were randomly applied to the triceps surae muscle of healthy participants using a crossover design. The NMES intensity, NMES-evoked torque, NMES efficiency, and NMES discomfort were measured in maximal and submaximal conditions. Statistical analyses were conducted using a two-way mixed-model ANOVA with repeated measures. Forty-four participants were included.

Results: Aussie currents produced higher evoked torque and efficiency in maximal and submaximal efforts, with higher perceived discomfort in maximal effort. Although the Australian current may cause greater discomfort at maximal efforts, it matches the Russian current in perceived discomfort at submaximal levels. The 20% duty cycle produced the highest efficiency in submaximal efforts.

Conclusion: In both maximal and submaximal efforts, the Aussie current demonstrated superior NMES efficiency, yielding higher torque with lower amplitude than the Russian current. Clinicians should take these findings into consideration when prescribing KFACs to optimize clinical outcomes.

Keywords: alternated current; burst‐modulated current; duty cycle; electrical stimulation; torque.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
(a) There was no difference between neuromuscular electrical stimulation. (NMES) protocols for NMES‐maximum evoked torque (NMES‐MET) normalized by the maximal voluntary isometric contraction (MVIC). (b) Aussie currents evoked higher relative evoked torques when compared to Russian currents in submaximal evoked torque (NMES‐SET) in KFACs conditions.
FIGURE 2
FIGURE 2
(a) Aussie currents evoked higher absolute neuromuscular electrical stimulation‐ maximum evoked torque (NMES‐MET) when compared to Russian currents in maximal in KFACs conditions. (b) Aussie currents presented a higher absolute NMES‐submaximal evoked torque (NMES‐SET) when compared to Russian currents in submaximal conditions.
FIGURE 3
FIGURE 3
(a) Aussie currents presented higher neuromuscular electrical stimulation‐efficiency (NMES efficiency) when compared to Russian currents in maximal kilohertz‐frequency alternating currents (KFACs). (b) Aussie currents presented higher NMES efficiency when compared to Russian currents in submaximal conditions. (c) The 20% duty cycle presented higher NMES efficiency than the 10% duty cycle.
FIGURE 4
FIGURE 4
(a) Aussie currents presented higher neuromuscular electrical stimulation‐discomfort (NMES discomfort) when compared to Russian currents in maximal kilohertz‐frequency alternating currents (KFACs). (b) There was no difference between NMES protocols for submaximal discomfort.
FIGURE 5
FIGURE 5
(a) Aussie currents presented lower generation of neuromuscular electrical stimulation intensity (NMES intensity) when compared to Russian currents in maximal kilohertz‐frequency alternating currents (KFACs). (b) Aussie currents presented lower generation of NMES intensity when compared to Russian currents in submaximal conditions. (c) The 20% duty cycle presented lower NMES intensity than the 10% duty cycle.
See this image and copyright information in PMC

References

    1. Bax, L. , Staes, F. , & Verhagen, A. (2005). Does neuromuscular electrical stimulation strengthen the quadriceps femoris? Sports Medicine, 35(3), 191–212. 10.2165/00007256-200535030-00002 - DOI - PubMed
    1. Bellew, J. W. , Beiswanger, Z. , Freeman, E. , Gaerte, C. , & Trafton, J. (2012). Interferential and burst‐modulated biphasic pulsed currents yield greater muscular force than Russian current. Physiotherapy Theory and Practice, 28(5), 384–390. 10.3109/09593985.2011.637286 - DOI - PubMed
    1. Bellew, J. W. , Cayot, T. , Brown, K. , Blair, C. , Dishion, T. , Ortman, B. , & Reel, A. (2021). Changes in microvascular oxygenation and total hemoglobin concentration of the vastus lateralis during neuromuscular electrical stimulation (NMES). Physiotherapy Theory and Practice, 37(8), 926–934. 10.1080/09593985.2019.1652945 - DOI - PubMed
    1. Botter, A. , Oprandi, G. , Lanfranco, F. , Allasia, S. , Maffiuletti, N. A. , & Minetto, M. A. (2011). Atlas of the muscle motor points for the lower limb: Implications for electrical stimulation procedures and electrode positioning. European Journal of Applied Physiology, 111(10), 2461–2471. 10.1007/s00421-011-2093-y - DOI - PubMed
    1. Bowman, B. R. , & McNeal, D. R. (1986). Response of single alpha motoneurons to high‐frequency pulse trains. Stereotactic and Functional Neurosurgery, 49(3), 121–138. 10.1159/000100137 - DOI - PubMed

Publication types

LinkOut - more resources