Practical Anatomy and Physiology: The Skeletal Muscle System
This article is the first in a series that summarizes the essential anatomy and physiology of the body systems that are trained in biofeedback and neurofeedback. This article examines the skeletal muscle system, the types of skeletal muscle fibers, motor units, muscle action potentials, the surface electromyographic signal, muscle contraction, sensory-motor integration, and practical recommendations for beginning biofeedback professionals.Abstract
Details of a muscle fiber. From Principles of Anatomy and Physiology, 12th edition, by Gerard J. Tortora and Bryan H. Derrickson © 2009 John Wiley & Sons, Inc. Reproduced with permission of John Wiley & Sons, Inc.
Incorrect and correct masseter placements. Photos courtesy of Tim Barcus (photographer) and Peter Schaffner (model), Truman State University.
As a muscle fatigues, the power density spectrum and the frequency spectrum shift to the left side of the frequency scale, and consequently, the median and mean frequencies decrease. Note that mean and median frequencies are relevant muscle fatigue indicators only for isometric contractions (sustained contraction with no movement). Graphic courtesy of www.thoughttechnology.com.
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