My wife is friends with an occupation therapist who has a broad range of knowledge about medical matters generally, and a slight inclination to alternative therapies. She demonstrated the following:
She asked someone to move their arm up their torso as if they were “zippering themselves up”, then extend their arm out and attempt to keep it level as she applied downward pressure. Then she “broke the field”, making a slashing X motion in front of their face, and repeated the extended arm bit. The idea was that the second time, the person had significantly less ability to withstand the downward pressure.
The consistently worked, even on people who were previously skeptical.
I’m convinced that it worked because of the belief that it should work on the part of the “tester”. Simply, her body worked in accordance with what she thought it should do, and she subconsciously put more downward pressure the second time than the first. From the perspective of the person being tested, there’s no difference between the sensation of the tester putting more pressure and the sensation of them having less strength to resist, and they attributed it to the latter out of the power of suggestion.
But what I’m curious about is whether anyone heard of this type of test, and what it’s supposed to represent, and has it ever been debunked etc.
[I remember that as a teenager a friend of mine once went to a chiropractor who did a very similar type of experiment with him. IIRC he asked him to visualize a clock and then to “look” at various positions on the dial while attempting to hold his knee up while the chiropractor pushed it down. Whenever he looked at the 3 (or perhaps it was the nine) he lost all ability to exert any counterpressure at all. I myself tried it on this guy and it worked, although I imagine that he may have fallen victim to the power of suggestion by this chiro. But who knows.]
It’s rather easy, in most people, to push down an arm that is extended straight out in front or to the side. The longer the arm, the greater the leverage. Additionally, the relatively weak muscle of the shoulder is all that holds it up. So the therapist could simply push down harder when she wanted the subject to fail the test.
A better test would be for the subject to push up on a dynamometer with their eyes closed. Then the therapist could randomly make the slashing gesture without the subject knowing about it, and see if the upward pressure was less.
I went (just once) to a chiropractor who did most of his diagnosing this way. He’d push down on your arm, flash little red lights at you or tap on your back or something and then push again to see if it helped. About halfway through, my shoulder joint popped. It felt like my ankle does when I sprain it. He was surprised and couldn’t think of anything that might help it. I guess it helped my back pain in the same sense that hitting your finger with a hammer helps a headache. So much for wacky new agers.
In any event, something like that is pretty clearly psychosomatic because there are too many variables. In addition to placebo effects on the subject, there are factors on the experimenter (which could be subconscious even for them) like how quickly the force is applied and how much force. My shoulder popped because he went from no pressure to lots of pressure almost instantly instead of building it up over a second, and I was aware of the fact that he was varying how quickly he applied the pressure.
This so-called ‘test’ is used to ‘prove’ many different things, within many different therapies and fields of study. It is most typically associated with applied kinesiology, as Contrapuntal has noted, but it crops up in many other places too.
It is complete and utter nonsense. It does not provide evidence of anything at all except that there are many variables in pushing down on an outstretched arm. The most significant of these variables is how quickly the experimenter pushes down and with what degree of force. This being the case the experimenter can, of course, achieve any result he or she wants. Under normal circumstances, it should be quite easy to push someone’s arm down because leverage favours the person doing the pushing down. Hence to ‘prove’ some sort of effect, the experimenter only has to apply less pressure the first time and ‘normal’ pressure the second time, or vice-versa.
If you ever meet someone offering this utterly specious demonstration, you are within your rights to point out that they are talking nonsense and to demand your money back.
What’s more, this is one form of nonsense that can be shown up for what it is relatively easily: when the experimenter does not know what the result is supposed to be, there is no ‘effect’ beyond what would be allowed for by random chance.
Example: you go and see some deranged idiot who thinks applied kinesiology has something going for it (it doesn’t). She (it’s usually a ‘she’) will tell you that when you are exposed to healthy stuff your body is stronger, but when you are exposed to bad stuff your body is weaker. For example, you hold something healthy (e.g. an apple) in your left hand and stretch out your right arm. Experiment pushes down on the arm, and ‘fails’ to move it. Then you hold something not nice in your left hand (e.g. something that would be toxic if eaten) and repeat, and this time your arm goes down. This is supposed to ‘prove’ that you are now weaker. There are many variations on this kind of ‘experiment’.
To prove that it’s all bogus: line up 12 people, and 12 opaque bags. Four of the bags contain an apple, four contain something toxic, and four contain nothing at all but you can’t tell just by looking which is which. Let the kinesiologist perform the test 12 times, and ask her to deduce what is in which bag. She will score no better than chance. This can even be done with one subject and 12 opaque bags.