Purpose: The present study was designed to investigate the electromyographic (EMG) response in leg muscles to whole-body vibration while using different body positions and vibration frequencies.
Methods: Twenty male sport sciences students voluntarily participated in this single-group, repeated-measures study in which EMG data from the vastus lateralis (VL) and the lateral gastrocnemius (LG) were collected over a total of 36 trials for each subject (4 static positions × 9 frequencies).
Results: We found that vibration frequency, body position and the muscle stimulated had a significant effect (P-values ranged from 0.001 to 0.031) on the EMG response. Similarly, the muscle × frequency and position × muscle interactions were significant (P < 0.001). Interestingly, the frequency × positions interactions were not significant (P > 0.05).
Conclusions: Our results indicate that lower frequencies of vibration (25-35 Hz) result in maximal activation of LG, whereas higher frequencies (45-55 Hz) elicit the highest responses in the VL. In addition, the position P2 (half squat position with the heels raised) is beneficial both for VL and LG, independently of the vibration frequency.
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http://dx.doi.org/10.1016/j.jelekin.2012.08.018 | DOI Listing |
J Phys Chem A
January 2025
Astrophysik/I. Physikalisches Institut, Universität zu Köln, Köln 50937, Germany.
The methoxy radical, CHO, has long been studied experimentally and theoretically by spectroscopists because it displays a weak Jahn-Teller effect in its electronic ground state, combined with a strong spin-orbit interaction. In this work, we report an extension of the measurement of the pure rotational spectrum of the radical in its vibrational ground state in the submillimeter-wave region (350-860 GHz). CHO was produced by H-abstraction from methanol using F atoms, and its spectrum was probed in absorption using an association of source-frequency modulation and Zeeman modulation spectroscopy.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States.
Two-dimensional infrared (2D IR) spectroscopy is a powerful technique for measuring molecular heterogeneity and dynamics with a high spatiotemporal resolution. The methods can be applied to characterize specific residues of proteins by incorporating frequency-resolved vibrational labels. However, the time scale of dynamics that 2D IR spectroscopy can measure is limited by the vibrational label's excited-state lifetime due to the decay of 2D IR absorption bands.
View Article and Find Full Text PDFJ Voice
January 2025
Department of Audio, Video, and Electronic Forensics, Academy of Forensic Science, Shanghai, China; Shanghai Forensic Service Platform, Key Laboratory of Forensic Science, Ministry of Justice, Shanghai, China.
Drug abuse can cause severe damage to the human speech organs. The vocal folds are one of the important speech organs that produce voice through vibration when airflow passes through. Previous studies have reported the negative effects of drugs on speech organs, including the vocal folds, but there is still limited research on relevant field.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
School of Perceptual Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
This paper presents a flat-type piezoelectric motor utilizing in-plane vibration modes. Two piezoelectric ceramic plates in combination with a brass metal sheet were used to construct the stator. The superposition of two second order in-plane vibration modes can generate a traveling-wave inside the stator.
View Article and Find Full Text PDFJ Chem Phys
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China.
Vibro-polaritons are hybrid light-matter states that arise from the strong coupling between the molecular vibrational transitions and the photons in an optical cavity. Developing theoretical and computational methods to describe and predict the unique properties of vibro-polaritons is of great significance for guiding the design of new materials and experiments. Here, we present the ab initio cavity Born-Oppenheimer density functional theory (CBO-DFT) and formulate the analytic energy gradient and Hessian as well as the nuclear and photonic derivatives of dipole and polarizability within the framework of CBO-DFT to efficiently calculate the harmonic vibrational frequencies, infrared absorption, and Raman scattering spectra of vibro-polaritons as well as to explore the critical points on the cavity potential energy surface.
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