View Full Version : MMG summary

Scott Mclean
03-30-1998, 06:52 AM
I have compiled a summary of the replies I received regarding
mechanomyography. After my second posting I received a great deal of
information and would like to thank those who took the time to respond
(Claudia Ranniger, Stephen Vaitl, Dr. H. Rassoulian, Wolfgang Loescher,
Roger Enoka, Leon Caillouet, Craig Nevin, Andrew Pinder, Mihai Tarata,
Bernard MATON, Paul Weinhold, Kevin Sims, Dr.JASRAJ SINGH, and Peter ???).
My summary includes information which I have stumbled upon as well as
information/issues that several of the respondents provided. Bernard Maton
provided a nice summary:

"Mechanomyography is also known as phonomyography, accoustic myography, or
or vibromyography !
The signal that is recorded corresponds to the vibrations which are
produced by the muscle contraction. When these vibrations are recorded by
means of an accelerometer taped onto the skin it is known as
acceleromyography or vibromyography. When it is recorded with a microphone
after propagation in the air it is known as phonomyography or accoustic
myography. Vibrations can also be recorded by means of laser apparatus.
Finally, mechanomyography is a less precise term which covers all of these
possibilities. Muscle sounds were first described in 1665 and there is
a great bulk of literature starting from 1860 until now."

The MMG signal is currently being used in research that tries to
distinguish between fiber types, detect muscle fatigue, diagnose muscle
diseases (e.g., myotonic dystrophy), and control prosthetics. The
transducers are microphones or capacitance accelerometers.

One issue that I found particularly interesting was the relationship
between the MMG signal and fatigue. MMG data suggests that fatigue may be
due to mechanical factors such as the failure of x-bridges to form. This
would cause less "vibration" from the muscle which would be indicated in a
change of the MMG signal.

Of course MMG technology is not without challenges. Several people
discussed its use in relation to EMG and raised several pertinent issues.
The major issues that I identified were 1) because it is a non-invasive,
surface technique, it is prone to interference from other sources of
vibration (e.g., movement artifact), and 2) just as EMG often needs
additional information for interpretation, so will an MMG signal.

I have included some other relevant information below.

Researchers in MMG
Claudio Orizio
Dan Barry - University of Michigan
Maria Stokes

Journals where MMG articles have been published
Muscle and Nerve
J Appl Phys
Eur J Appl Occup Physiol
J Biomech

"A comparative study of simultaneous vibromyography and electromyography
with active human quadriceps" by Zhang, Frank, Rangayyan, and Bell. It is
found in Vol. 39, #10, October 1992 of IEEE Transactions on Biomedical
Engineering, pages 1045-1052.

Muscular force in running turkeys: the economy of minimizing work .
Roberts TJ, Marsh RL, Weyrand PG, Taylor CR, Science 275, 21 Feb
1997, p1113-1115.

Orizio, C. "Muscle Sound: Bases for the Introduction of a Mechanomyographic
signal in muscle studies", Critical Reviews in Biomedical Engineering,
21(3):201-243 (1993)

Barry, D.T. - Vibrations and sounds from evoked muscle twitches,
Electromyogr. clin. Neurophysiol., 1992, 32, 35-40

Claudio Orizio, et al. - Surface mechanomyogram reflects muscle
fibres twitches summation, J. Biomechanics, vol. 29, no.4, pp.
475-481, 1996

Tarata, M., Spaepen, A., Puers, R., Hermans, Veerle (1997).
The Potential of Simultaneously recordingthe EMG and Muscle
Mechanical Vibrations in Monitoring the Muscle Behaviour, in
Proceedings of the International Conference on Measurement,
Smolenice, Slovak Republic, May 29-31, pp. s1-s4, 1997

Tarata, M. (1997). Monitoring the Evolution of the Muscular
Fatigue, Via New Parameters developed from the EMG Signal,
proceedings of the ECSAP'97 The First European Conference on
Signal Analysis and Prediction, Prague, Czech Republic, 24-27
June 1997, pp. 431-434, 1997
Scott P. McLean, Ph.D.
Assistant Professor
Department of Health and Human Performance
255 Forker Building
Iowa State University
Ames, IA 50011
(515) 294-8755 FAX (515) 294-8740
email: smclean@iastate.edu