When I first was in chiropractic school I was exposed to Applied Kinesiology and thought it was pretty cool. The basic muscle testing seemed really interesting and valuable to me. Kendal and Kendal in the orthopedic world was the gold standard in text books for muscle testing. There seemed to be certain positions that would "isolate" the muscles and provide feedback if they were "strong."
I put quotes on the words isolate and strong for a reason. We know now that isolation of muscles is pretty much impossible. You can't test your quad without the hamstring firing to support them as an example. You don't contract your biceps without the bracialis being used as well as the triceps and even further away like the lat. Dynamic systems theory states that with each time you test a muscle you are most likely not even testing the same fibers.
You then bring in bias by the tester. Some are great testers and don't help, but as a therapist we all want to get people better, subconsciously we must assume we retest differently.
I took a course called NKT awhile back and found some value in the methods. I still use a few of the tests. Knowing what we know about isolation I get confused every now and then about what I'm actually testing. 5 years ago, I would have said I'm testing your glute medius for example. Can your strength resist adduction. 1 year ago, nI would have said I'm testing your position not a muscle. Can those muscles in that area produce stability.
Lately, I'm thinking I am simply asking the body what tension is the brain paying attention to in the position the joint is placed in. If I put the hip into abduction but there is so much tension in the quadriceps, then not enough neural drive is happening into the muscles that can resist adduction. The brain can only find the quadriceps which can't generate the requisite force to resist adduction.
Take some tension away from the quads and you have a window of opportunity to retrain the hip as an example. (This is not always the case, just an example.)
I go back and for the with the value I find in muscle testing. I firmly believe that a person should be able to lock in any joint under testing. It just seems correct. But, I also think you are not really testing muscles. Therapists can have doubts.
The key to all of this to me is gaining that window of opportunity. Using it to train a load bearing exercise after a therapy session or a rolling session. Hundreds of repetitions. Taking tension away from one area to gain better access to another.
This was more of a personal post then anything else. I wonder if any other therapists have these thoughts?