Well, Susan, I guess it depends on the client. So many times I tell clients to contract, tighten or a muscle, they can’t do it. However, when I say squeeze or worse yet, flex that muscle, they know exactly what I’m talking about. We all know we can only flex a joint, not a muscle. But sometimes, you have to go out of your comfort zones to get your point accross.
In my many years in the fitness industry I’ve wondered the same thing! But then I’ve heard lots of things using terms and descriptions that clearly are based on academic correctness.
I think it just means to contract the target muscle with maximal of near-maximal effort. I also think that if it gets your client or your students to contract or engage the target muscle with signficant effort the word description of what they’re doing isn’t all that important!
I don’t use “squeeze”. It is too general and unclear. I do use contract, stabilize, brace, engage, prepare, etc. as the moment and movement require. I spend a fair amount of time teaching clients and students what each “cue” refers to and how to connect the mind to the muscle/movement. This teaching process goes on pretty much indefinitely for many clients and some students. And often it is necessary to modify cues until you come to one that works for a specific client in a specific situation.