Many, many out of shape people have bad posture and alignment. When they take up running or some other vigorous exercise to lose weight and get in shape, they just end up hurting themselves because of their posture. If a person is seriously out of shape, I always recommend a serious posture discipline like T'ai-Chi or Yoga for a full year before more vigorous exercise. But of course for your average American a full year seems like 20. They want it now!
And, this is the big one: It's not "T'ai-Chi" which gives these benefits, but a good T'ai-Chi PRACTICE. You have to practice, and practice well, to get these benefits. It's not a pill, it's work, and that is why these articles come and go every year or two and by and large we continue to get less and less healthy as a nation.
For anyone interested in turning this around in their life or the life of someone they know, I recommend my book "T'ai-Chi For Geniuses-A Practice Companion For The Genius In Everyone". Click on this link and once there you can buy it if you want, but there's also a link to read the Introduction to the book free.