Mechanomyography

Abstract

This chapter on surface mechanomyography (MMG) is aimed to provide basic information about a relatively new biological signal detectable at the muscle surface during contraction. The text will deal with the definition and terminology; the relationship between the activity of the single motor units and the signal generation process and, as a consequence, on the MMG reliability as a tool to reveal the motor units activation strategy, the relationship between MMG and muscle mechanics to disclose the possible use of this signal to get information about muscle contractile properties; and finally some examples of practical applications in physiological and clinical studies. The goal of this chapter is not to provide an extensive review on the MMG but only to underline some physiological and technical aspects that the spreading of its use may be based on.

Analysis of crosstalk in the mechanomyographic signals generated by forearm muscles during different wrist postures

“…1 Thus, MMG records and quantifies the dimensional changes in muscle fibers and their displacement during activation of propagated mechanical waves through surrounding tissues. 2,3 During almost all voluntary muscle actions, MMG summates dimensional changes in the fibers of each linear or nonlinearly recruited motor unit 2,3 The MMG signal can be detected with surface sensors, namely microphones, piezoelectric contact sensors, accelerometers, or laser distance sensors. 2 Of these sensors, accelerometers are most often recommended, because they provide the most convenient and accurate measurements.…”

“…2,3 During almost all voluntary muscle actions, MMG summates dimensional changes in the fibers of each linear or nonlinearly recruited motor unit 2,3 The MMG signal can be detected with surface sensors, namely microphones, piezoelectric contact sensors, accelerometers, or laser distance sensors. 2 Of these sensors, accelerometers are most often recommended, because they provide the most convenient and accurate measurements. [4][5][6][7][8] Although the MMG technique has been recently adapted as a noninvasive alternative to surface electromyography (sEMG) for assessment of the conditions of muscle function, 6,9 some factors limit its applicability for examination of muscle activity comprehensively.…”

Short-term repeatability of parameters extracted from radial displacement of muscle belly

“…Apart from standard methods such as torque and/or force dynamometry, electromyography (EMG) seems to be currently the most frequently used method both in clinical environment and in research. However, despite its frequent use, the reliability of the methods as well as underlying physiology remains to be a subject of continuous investigations (Gerrits et al, 2001;Elfving et al, 1999;Kollmitzer et al, 1999;Mathur et al, 2005;Merletti et al, 1995;Orizio, 2004;Ollivier et al, 2005;Peach et al, 1998;Rainoldi et al, 2001;Rainoldi et al, 1999;Rau et al, 2004). Hence, there is a continuing interest in development of complementary methods that could improve our understanding of muscle contraction properties.…”

“…Mechanomyography (MMG) based on recording of a mechanical response (vibrations) of muscle fibers either on voluntary (Bizzini and Mannion, 2003) or electrically-evoked contraction is one of such methods with several variations depending on the variety of sensors used (microphone, accelerometer, laser, etc.) (Orizio, 2004). However, the principles of the method, parameter identification, reliability and correlation to other methods are still investigated.…”

Novel insights into skeletal muscle function by mechanomyography: from the laboratory to the field

“…The pressure waves transmitted from the active muscle fibres to the skin surface can be detected by specific transducers to record muscle surface oscillations related to motor units' (MUs) mechanical activity [2,15]. Several types of transducers can be used, among which piezoelectric contact sensors (PIZ), microphones (MIC), laser distance sensors (LDS), electret condenser microphones (ECM), and accelerometers (ACC), which is largely the most used sensor for MMG detection.…”