I’ve seen numerous “alternative medicine” providers perform something they call “muscle testing” or “muscle energy testing” many times as part of their sales pitch. They tell you to put one arm out in front of you, and then push down on your arm. Your arm sinks immediately.
Then they ask you a question, or put some kind of substance or herbal remedy in your opposite hand, and repeat the “test.” Your arm always stays up better the second time. The explanation the quacks will give you is that your body “knows what is best for it” and that your arm is somehow “in tune with the universe” enough to know that what you’re holding in your opposite hand will help you.
As this video points out, none of this is true. The reason your arm does a better job of resisting the force the second time around is simply because your body has learned what to expect. As John Duffy, the physical therapist in the video, points out, this represents “simple motor learning.” In the video, he uses his “magic pen” as a joke to represent the “treatments” that some unethical “alternative health” providers con people into taking using this test.
This video was originally posted on the Phoenix Rehabilitation and Health Services, Inc. Facebook page. I am including the link to view it on the blog Forward Thinking PT because that is where I originally viewed it, and it seemed to come out in a higher quality there. (Although I have to admit that this may have more to do with the fact that my computer is ancient than anything else…).
Thanks to EUSKALANATO on Flickr for making the above photo available.