@article{c7d2e23906d245ec85c82dadcf7b9a5c,
title = "A noninvasive, log-transform method for fiber type discrimination using mechanomyography",
abstract = "This study examined the log-transformed mechanomyographic (MMGRMS) and electromyographic (EMGRMS) amplitude vs. force relationships for aerobically-trained (AT), resistance-trained (RT), and sedentary (SED) individuals. Subjects performed isometric ramp contractions from 5% to 90% maximal voluntary contraction. Muscle biopsies were collected and thigh skinfolds, MMG and EMG were recorded from the vastus lateralis muscle. Linear regression models were fit to the log-transformed EMGRMS and MMGRMS vs. force relationships. The slope (b coefficient) and the antilog of the y-intercept (a coefficient) were calculated. The AT group had the highest percentage of type I fiber area, the RT group had the highest percentage of type IIa fiber area, and the SED group had the highest percentage of type IIx fiber area. The a coefficients were higher for the AT group than the RT and SED groups in both the MMGRMS and EMGRMS vs. force relationships, whereas the b coefficients were lower for the AT group than the RT and SED groups only in the MMGRMS vs. force relationship. The group differences among the a coefficients may have reflected subcutaneous fat acting as a filter thereby reducing EMGRMS and MMGRMS. The lower b coefficients for the AT group in the MMGRMS patterns may have reflected fiber area-related differences in motor unit activation strategies.",
keywords = "EMG, Electromyography, MMG, Motor unit activation strategies",
author = "Herda, {Trent J.} and Housh, {Terry J.} and Fry, {Andrew C.} and Weir, {Joseph P.} and Schilling, {Brian K.} and Ryan, {Eric D.} and Cramer, {Joel T.}",
note = "Funding Information: We would like to acknowledge Michael J. Falvo and Christopher A. Moore for their contribution to this project. The results of the present study do not constitute endorsement by ACSM. under the mentorship of Dr. Joel Cramer. He received a BS (2005) degree in exercise science from the University of Sioux Falls, Sioux Falls, South Dakota, and a MS (2007) degree from the University Oklahoma, Norman, Oklahoma, in exercise physiology. He is member of the American College of Sports Medicine (ACSM), National strength and Conditioning Association (NSCA), and International Society of Electrophysiology and Kinesiology (ISEK). His primary research interests include noninvasive assessment of muscle function and the acute effects of vibration and passive stretching on mechanical and neural components of muscular contraction. Trent J. Herda is originally from Iowa, and is currently a doctoral student in the exercise physiology department at the University of Oklahoma Terry J. Housh received a BA (1977) degree in Physical Education from Doane College, Crete, NE, and MPE (1979) and Ph.D. (1984) degrees from the University of Nebraska-Lincoln. He is a Fellow of the American College of Sports Medicine, Fellow in the research Consortium of AAHPERD, and received the 1998 Outstanding Sport Scientist Award from the National Strength and Conditioning Association. Presently, he is a Professor in the Department of Nutrition and Health Sciences, Director of the Exercise Physiology Laboratory, and Co-Director of the Center for Youth Fitness and Sports Research at the University of Nebraska-Lincoln. His main areas of research are muscle function, fatigue, and growth and development in young athletes. Andrew C. Fry is currently the chair of the Department of Health, Sport & Exercise Sciences at the University of Kansas where he is also a professor in the exercise science program. Currently, his research interests include the muscle, endocrine and performance responses and adaptations to resistance exercise, as well as overtraining. Joseph P. Weir received his undergraduate degree in Exercise Science from Eastern Washington University and a doctorate in Exercise Physiology from the University of Nebraska. His primary research interests concern the responses of the neuromuscular system and autonomic nervous system to exercise. Dr. Brain K. Schilling{\textquoteright}s area of research is the mechanics of human movement as pertains to responses and adaptations to exercise training in athletic, healthy, and aging populations, as well as in individuals with disabilities or neuromuscular disease. Of prime importance is the influence of the neuromuscular system on force development and time-dependent variables of muscular strength. Currently the he is developing procedures for measuring muscle activity, balance and strength performance in aging persons and persons with Parkinson disease, and examining the effects of exercise in such populations. Eric D. Ryan is currently an Assistant Professor at Oklahoma State University in the Health and Human Performance Department. He received his Ph.D. under the mentorship of Dr. Joel Cramer in 2009 from the University of Oklahoma. His primary research interests include the non-invasive assessment of muscle function. Dr. Joel T. Cramer is currently an Assistant Professor and Co-director of the Biophysics Laboratory in the Department of Health and Exercise Science and Adjunct Assistant Professor in Industrial Engineering at the University of Oklahoma. Dr. Cramer received a bachelor{\textquoteright}s degree in Exercise Science from Creighton University in 1997 and a master{\textquoteright}s and doctorate in Exercise Physiology from the University of Nebraska-Lincoln in 2001 and 2003, respectively, under the mentorship of Dr. Terry J. Housh. His primary research interests include the relationships among muscle force production, surface electromyography (EMG), and mechanomyography (MMG) during isometric, isokinetic, and dynamic constant external resistance muscle actions. ",
year = "2010",
month = oct,
doi = "10.1016/j.jelekin.2010.01.004",
language = "English (US)",
volume = "20",
pages = "787--794",
journal = "Journal of Electromyography and Kinesiology",
issn = "1050-6411",
publisher = "Elsevier Limited",
number = "5",
}