TITLE

The surface mechanomyogram as a tool to describe the influence of fatigue on biceps brachii motor unit activation strategy. Historical basis and novel evidence

AUTHOR(S)
Orizio, Claudio; Gobbo, Massimiliano; Diemont, Bertrand; Esposito, Fabio; Veicsteinas, Arsenio
PUB. DATE
October 2003
SOURCE
European Journal of Applied Physiology;Oct2003, Vol. 90 Issue 3/4, p326
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The surface mechanomyogram (MMG) (detectable at the muscle surface as MMG by accelerometers, piezoelectric contact sensors or other transducers) is the summation of the activity of single motor units (MUs). Each MU contribution is related to the pressure waves generated by the active muscle fibres. The first part of this article will review briefly the results obtained by our group studying the possible role of motor unit recruitment and firing rate in determining the characteristics of the MMG during stimulated and voluntary contractions. The second part of this article will study the MMG and EMG during a short isometric force ramp from 0 to 90% of the maximal voluntary contraction (MVC) in fresh and fatigued biceps brachii. The aim is to verify whether changes in motor unit activation strategy in voluntarily fatigued muscle could be specifically reflected in the time and frequency domain parameters of the MMG. MMG-RMS vs. %MVC: at fatigue the MMG-RMS did not present the well known increment, when effort level increases, followed by a clear decrement at near-maximal contraction levels. MMG-MF vs. %MVC: compared to fresh muscle the fatigued biceps brachii showed an MF trend significantly shifted towards lower values and the steeper MF increment, from 65 to 85% MVC, was not present. The alteration in the MMG and EMG parameters vs. %MVC relationships at fatigue seems to be related to the impossibility of recruiting fast, but more fatigable MUs, and to the lowering of the global MUs firing during the short isometric force ramp investigated.
ACCESSION #
16821689

 

Related Articles

  • Erratum: 'Small-scale piezoelectric devices: Pyroelectric contributions to the piezoelectric response' [J. Appl. Phys. 107, 104118 (2010)]. Wooldridge, Jenny; Blackburn, John F.; McCartney, Neil L.; Stewart, Mark; Weaver, Paul; Cain, Markys G. // Journal of Applied Physics;Apr2011, Vol. 109 Issue 7, p079901 

    A correction to the article "Small-scale piezoelectric devices: Pyroelectric contributions to the piezoelectric response" that was published in a previous issue is presented.

  • Two-Dimensional Electroelastic Problem for a Multiply Connected Piezoelectric Body. Kaloerov, S. A.; Baeva, A. I.; Glushchenko, Yu. A. // International Applied Mechanics;Jan2003, Vol. 39 Issue 1, p77 

    In this paper, we present the basic relationships for the complex potentials of a two-dimensional electroelastic problem, their general representations for a multiply connected domain, expressions for stress, displacement, electrostatic field intensity and induction, and potential. A closed...

  • An ultrasonic stage for controlled spin of micro particles. Zhou, Yujie; Li, Huaqing; Hu, Junhui // Review of Scientific Instruments;Apr2012, Vol. 83 Issue 4, p045004 

    In this work, we proposed and developed an ultrasonic stage which can make different kinds of micro particles spin at its center. The stage consists of a circular copper plate and two piezoelectric half-rings bonded onto the bottom surface of the copper plate. The two piezoelectric half-rings...

  • Low-cost quest. Lee, Andrew // Engineer (00137758);6/25/2004, Vol. 293 Issue 7654, p9 

    Announces the plans of Cranfield University researchers to develop a piezoelectric motor suitable for low-cost mass production. Goal of the university to commercialize the motor as a smaller, cheaper alternative to conventional electromagnetic motors.

  • Two Decades Following the Discovery of Thermally Stable Elastic Properties of La3Ga5SiO14 Crystal and Coining of the Term �Langasite� (A Review). Andreev, I. A. // Technical Physics;Sep2004, Vol. 49 Issue 9, p1101 

    Twenty years ago, in December 2003, the Editorial Board of Technical Physics received a paper entitled �The New Piezoelectric Material �Langasite� La3Ga5SiO14 with Zero Temperature Coefficient of the Elastic Vibration Frequency.� This paper marked the beginning of a new stage...

  • Piezoelectric Energy Harvester Generates 40 μW.  // Power Electronics Technology;Jul2007, Vol. 33 Issue 7, p10 

    The article discusses the application of piezoelectric energy-harvesting device in generating electrical power. The device is developed to estimate the specific designs of the output power. It is stated that the output power can be maximized by optimizing the quality factor Q through...

  • A novel drum piezoelectric-actuator. Sun, C.L.; Lam, K.H.; Chan, H.L.W.; Zhao, X.-Z.; Choy, C.L. // Applied Physics A: Materials Science & Processing;Sep2006, Vol. 84 Issue 4, p385 

    This paper presents a large displacement, piezoelectric-metal structure actuator, named the piezoelectric drum actuator. The drum actuator consists of a short, thick-walled steel cylinder sandwiched by two thin composite disks, which are fabricated from a brass disk bonded with a piezoceramic...

  • Determination of antibodies to Yersinia enterocolitica bacteria using a piezoelectric quartz crystal immunosensor. Kalmykova, E.; Dergunova, E.; Zubova, N.; Gorshkova, R.; Komandrova, N.; Ermolaeva, T. // Journal of Analytical Chemistry;Oct2007, Vol. 62 Issue 10, p970 

    A gravimetric technique is proposed for the determination of antibodies to Yersinia enterocolitica serovar O: 3 using a piezoelectric quartz crystal immunosensor based on immobilized lipopolysaccharides. Conditions are optimized and a procedure is developed for the flow-injection analysis of...

  • Simulation and optimization of a piezoelectric micropump for medical applications. Cui, Qifeng; Liu, Chengliang; Zha, Xuan // International Journal of Advanced Manufacturing Technology;Mar2008, Vol. 36 Issue 5/6, p516 

    We designed a valveless micropump excited by a piezoelectric actuator for medical applications. The complete electric–fluid–solid coupling model is built upon using ANSYS software (Canonsburg, PA) to investigate the behaviors of the micropump. The effects of the geometrical...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics