Houston Methodist. Leading Medicine

Shoulder FAQ


I read about a study that used EMG recording of muscles to find good exercises for the shoulder. How do they know for sure the device isn’t picking up signals from nearby muscles?


This is a very good question and a problem that researchers have to deal with everyday. Electromyography (EMG) is the tool used to measure electrical activity in muscles. EMG tells researchers a lot about how muscles work. There are two ways to hear and record the electrical signals of muscles. Small patches or electrodes can be placed on the skin over the muscle. The electrodes are placed over the middle section of each muscle. This method gets the best signal without picking up signals from other muscles. A second method uses fine-wire electrodes. Fine needles are inserted in to the belly of the muscle. The wires are taped down to keep them from moving when the muscle contracts. Fewer muscle fibers are recorded with wires compared to electrodes. Scientists know that cross-talk is a problem with EMG studies. They take this into account when looking at their findings. Tim L. Uhl, PT, PhD, ATC, et al. Shoulder Musculature Activation During Upper Extremity Weight-Bearing Exercise. In Journal of Orthopaedic & Sports Physical Therapy. March 2003. Vol. 33. No. 3. Pp. 109-117.

*Disclaimer:* The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.
All content provided by eORTHOPOD® is a registered trademark of Medical Multimedia Group, L.L.C.. Content is the sole property of Medical Multimedia Group, LLC and used herein by permission.

Our Specialties

Where Does It Hurt?

Our Locations

  Follow Us

Follow us on Facebook Follow us on YouTube
Follow us on Twitter