Nick Tumminello makes an interesting point about the practice of personal training here:

I’m afraid our industry (the Fitness Industry) maybe getting overly caught up thinking we need to "fix" everyone’s problems because I regularly see fitness clients being treated like a re-hab patients and not nearly enough actual Strength & Conditioning is getting done.

This is a compelling point: shouldn't a Strength and Conditioning Coach be focusing primarily on, well, strength and conditioning? Shouldn't a client of such a person wind up stronger and more enduring? And if so, what's with all the concern about postural imbalances, glute activation, length-tension relationships, and the like, among personal trainers and the people who certify and train them? Shouldn't we personal training types largely concern ourselves with building muscle, burning fat, and building a tougher, healthier, more enduring cardiovascular system?

I'm a big fan of Tumminello--and of J.C. Santana, whom Tumminello quotes at some length in his blog entry on assessments. And I agree with his point that you can fall down an assessment wormhole in which the trainer never gets around to really giving his client a workout because he's too concerned with creating 100% crystalline perfect posture and movement mechanics first. I also believe that learning to move a load effectively can be a pretty good way of learning to move well. If you can squat with good mechanics, for instance, it's a good sign that your lower body mobility is pretty spot-on.

However, I also think that the line between personal training and physical therapy can be razor-thin. You can't, after all, affect the muscles without also affecting the nervous system, and vice-versa. Improve movement efficiency and mechanics and you DO improve strength. I used to believe--primitively--that muscular strength and size was the key to all things athletic and strength-related. But it just ain't. That's the bodybuiding model, which of course has its merits but is actually quite limited in its perspective. The muscles are the final link in the kinetic chain, but they're supported and controlled by the nervous system, which needs tuning and training every bit as much as the muscles themselves--probably more so. Great athletes, after all, are way more than big, strong muscles--otherwise powerlifters would be the best all-around athletes in the world. And, due respect, they're not.

Any good trainer will actually spend time training the nervous system whether he knows it or not: anything plyometric, power-based, or strength-based in the 90% 1RM zone is going to impact the nervous system to a large extent. The average trainer would call these 'personal training' or 'athletic training' modalities, but they have a therapeutic benefit as well: the body is learning how to move better.

This is getting away from Nick's point about overdoing it on assessments, but my point is that therapy and training actually have a lot in common and that it may be short-sighted to draw too hard a line between them.