Due to our annual inventory count, Human Kinetics is currently not shipping orders February 18-20. We will resume shipping orders February 21. For more detailed information, please call 1-800-747-4457 during our normal business hours of 7:00am-5:00pm CST Monday through Friday.

Your order is important to us and we apologize for the inconvenience. Thank you for your patience.

Shopping Basket 0
Human Kinetics Publishers, Inc.



Noninvasive methods of examining muscle architecture and quality

This is an excerpt from Physiological Aspects of Sport Training and Performance With Web Resource, Second Edition by Jay Hoffman, PhD.

In Practice

Examining Muscle Architecture and Muscle Quality Noninvasively

A relatively new noninvasive method to investigate changes in muscle architecture is becoming popular. The use of ultrasonography to image muscle structure has proven to be a valid and reliable method of examining changes in muscle. The validity of ultrasound measures has been compared to that of both computed tomography (CT scans) and magnetic resonance imaging for analyzing large muscle groups (Reeves, Maganaris, and Narici 2004; Thomaes et al. 2012). The benefit of ultrasound compared to these other methods is related to the lower cost of operation and ease of use. With the other methods, physician prescription and the use of radiology technicians are often required.

Ultrasound measures are commonly used to assess muscle thickness, muscle cross-sectional area, fascicle length, and muscle fiber pennation angle. Improvements in our understanding and use of ultrasonography have resulted in a relatively new measure known as echo intensity. Echo intensity is the quantification of muscle quality using grayscale analysis from image analysis software (Cadore et al. 2012). The imaging software analyzes the pixel count that is obtained using the ultrasound image of skeletal muscle (generally the vastus lateralis, rectus femoris, or both) and provides a score that is based on an arbitrary units scale ranging from 0 to 256 (0: black; 256: white). Figure 1.9 provides an example of an echo intensity analysis. A lower number (lower echo intensity) is reflective of an increase in muscle quality. Echo intensity is indicative of the architectural characteristics of muscle, including the infiltration of adipose, connective, and other noncontractile tissue into the muscle. Skeletal muscles with greater lean tissue, less fat, and connective tissue have a lower echo intensity.

Echo intensity of the rectus femoris.


In a study of older (70.4 ± 5.5 years), healthy Japanese women, echo intensity values were found to significantly correlate with isometric knee extensor strength (r = -0.40, p \lte\ 0.01), independent of age or muscle thickness of the quadriceps femoris (Fukumoto et al. 2012). In addition to its use as a marker of muscle quality, echo intensity may provide a sensitive and reliable measure of muscle damage and recovery. Radaelli and colleagues (2012) assessed echo intensity prior to the onset of exercise and following four sets of 10 repetitions at 80% of the subjects’ maximal elbow flexor strength in the dominant arm at 24, 48, and 72 hours postexercise. Echo intensity values were significantly elevated from preexercise values at all three time points, whereas no change from baseline was seen in the nondominant (no-exercise) arm. These results suggested that echo intensity may be quite useful as a sensitive marker for recovery from resistance exercise. A number of studies on this unique measure of muscle quality will be published over the next few years.

Learn more about Physiological Aspects of Sport Training and Performance With Web Resource, Second Edition.

Facebook Reddit LinkedIn Twitter

The above excerpt is from:

Physiological Aspects of Sport Training and Performance With Web Resource-2nd Edition

Physiological Aspects of Sport Training and Performance With Web Resource-2nd Edition

View other formats

More excerpts from this book

Physiological Aspects of Sport Training and Performance With Web Resource-2nd Edition

Related Excerpts

Get the latest news, special offers, and updates on authors and products. SIGN UP NOW!

Human Kinetics Rewards

About Our Products

Book Excerpts


News and Articles

About Us

Career Opportunities


Business to Business

Author Center

HK Today Newsletter


Exam/Desk Copies

Language rights translation

Associate Program

Rights and Permissions





Certifying Organizations

Continuing Education Policies

Connect with Us

YouTube Tumblr Pinterest

Terms & Conditions


Privacy Policy


Safe Harbor