Primal On Strength and Flexibility

http://donmatesz.blogspot.com/2011/01/study-strength-training-improves.html

"Primal" blogs about the connection between strength and flexibility - nice study review, but this is obvious, nearly all the really flexible people in the world are also very strong.  Gymnasts, martial artists, olympic weightlifters, dancers, yogis - all are very, very strong.  There's a reason why this connection exists, of course, which is that the body has unconscious mechanisms which limit movements which are perceived as unsafe.  One of the feedback mechanisms senses the degree to which a position is unfamiliar, another perceives a sort of "strength excess"; IOW, it takes no strength to speak of to maintain structural integrity when standing still, but quite a bit to sustain the structure when a limb is bending to the limit of its movement range.  In short, if you squat like your kids can, and do, your body perceives it as a natural position, and maintains a natural level of strength in a full, butt to the ground squat.  But if you do what most of us do, you rapidly lose the ability to squat well, or at all, as you lose strength in that range of motion, and the nervous system then works against even letting you into a full squat position by contracting muscles unconsciously to limit full range of motion.
Watching a normal adult try to get into a squat is painful.  It's painful to consider how much of our natural movement capacity we just give away due to ignorance.  It's correspondingly pleasant to watch an adult re-learn how to squat, and the resulting health that squatting well gives to the knees, back, and hips of the neo-squatter.
The takeaway from my perspective is that strength training - doing something to maintain muscular contractile force through a long, full, natural range of motion - is essential to a full, long, productive, healthy life.  Walking, running, cycling, swimming, hiking, etc, are all great things to do, and far, far better than doing nothing.  But for those that are committed to sustaining a useful body, those modalities are little more than a good start, and leave many fitness and health bases uncovered.