Is Flexibility All About Strength

[Jhaek]

I was surfing the internet when I found this topic - http://www.martialartsplanet.com/forums/showthread.php?t=85373&page=5 and as you can see the writer says that "Dynamic flexibility, and dynamic stretching, is a fallacy. It is no more safe or effective than ballistic stretching, which is a big no-no. Don't use methods which rely on tissue extensibility for flexibility, but those which focus on building strength in extended positions." would you agree/disagree?

[Joshua Slocum]

Dynamic stretching is not a technique for gaining flexibility. It is a warm up technique. This guy has absolutely no clue what he's talking about. In the same post, the same guy claims that stretching is unnecessary if you just do full ROM weightlifting twice a week. 

 

Physiologically, there are two primary constraints on flexibility: the tendon length and elasticity of the muscle groups opposing the motion, and the range of motion in which the active muscle groups are strong. Tendons are generally the limiting factor in what is called 'passive flexibility': how far your limb can move when you or another person or a weight are actively pushing on it. 'Dynamic flexibility', which is a measure of how far your limbs can move under their own power, is limited by your passive flexibility and the strength of your muscles. You can not develop dynamic flexibility unless you already have excess passive flexibility.

 

The tendons limit how wide your total range of motion is: if you try to move the joint beyond the tendon's resting length, it will begin to stretch. Once it reaches the limit of its elongation, moving the joint further can only occur if the tendon tears. Static stretching develops your maximal ROM in two ways that I know of. First, by pushing your tendons close to their maximal elongation. The tension causes micro-tears in the tendon (similar to how strength-training causes micro-tears in the muscle fibers), and when the tendon repairs itself, it will grow back slightly longer. The second mechanism is neurological: in response to the stretching stimulus, the nervous system decreases resting tension in the muscle groups, which makes it easier to reach maximum elongation more quickly. 

 

If you work only on developing strength in near-maximal ROM, you will always be fighting your own muscles for flexibility. As you approach the edge of your range of motion, you will have to push harder and harder because the opposing muscle groups and tendons will be resisting the movement. This is bad for two reasons. First, because you could more efficiently develop flexibility by putting more effort into static stretching, and second because you are at risk of injuring yourself by trying to elongate the tendons too quickly. 

 

The only technique to safely develop passive flexibility is static stretching. (This can be augmented with mobility work, but you won't get very far with just mobility work). To develop dynamic flexibility, you first need a solid foundation of passive flexibility. Then, doing mobility work and strength training at the extremes of your ROM can help.