In the video above by FXNL Media, Dr. Greg Lehman, MScPT, a physiotherapist based in Canada, starts by explaining how some of the top-performing athletes in the world have glaring postural flaws that many experts would cringe at. He goes on to say: "Those things aren't really flaws. We've just called them flaws and we don't really have a good reason to do that." For example, he cites one of the world's top marathoners as having a huge amount of pronation (generally thought of as a bad thing). "These are just normal patterns for them," Lehman explains, "The body is pretty amazing and adaptable."
This is not to say we shouldn't care about posture. Rather, we might just be placing too much importance on an ideal posture. The thinking goes, if we don't fall exactly under that, then we feel we are in dire need of fixing. Lehman sums it up like this:
Sometimes it doesn't matter what posture you're in, it's going to hurt and [then] it feels better to do something else. Maybe it's the lack of movement that's the bigger problem.
Where posture matters more, according to Lehman, is during high-load activity, where you're lifting heavy weights, jumping and landing from a great height, or playing on the sports field; and if your posture is part of a daily habit that keeps aggravating pain. In other words, it's not that your hunched-over sitting position is necessarily a bad thing. What's "bad" is that you continue to sit for hours and days in a way that pisses off your body.
If there's a posture or exercise form that hurts you, then it's not good for you no matter how "textbook" or perfect it is. For more details, hit the play button and give the video a watch.