Dynamic measurement of pennation angle of gastrocnemius muscles during contractions based on ultrasound imaging

Researchers in separate institutes in China collaborated to create a novel method of measuring pennation angles during contractions in muscles. Pennate muscles are muscles that have a resting oblique attachment angle to their respected tendon. These pennate muscles allow for a relatively greater amount of force production while also limiting range of motion. The pennation angle, the angle formed between the muscle fibers and the muscle's line of action, is an important parameter in measuring the functionality of a specific muscle. The method proposed by researchers includes using ultrasonic imaging to measure both deep aponeurosis and muscle fascicles during contraction and after a using a set of involved algorithms, producing the pennation angle for a muscle during contraction. Aponeuroses are broad layers of flat tendon. Muscle fascicles are bundles of skeletal muscle fibers surrounded by connective tissue. The researchers measured the pennation angle in the gastrocnemius of a subject. Manual methods of estimating pennation angles exist. Researchers had two experts manually determine the pennation angle of the gastrocnemius in the subject. The results between the two experts and the algorithm showed good correlations. Researchers hope to expand their methods in the future to allow for measurements in other muscles besides the gastrocnemius. Researchers are optimistic that this new method of measuring pennation angles with ultrasound imaging will allow for faster and more efficient measurements of muscles' functionality.
http://www.biomedical-engineering-online.com/content/11/1/63