Functional flexibility

We hear so much about the need to stretch, especially as athletes. We are told to stretch before and after exercising. But what is stretching, physiologically? The conventional thinking is that you are taking your muscles and forcing them to lengthen until they change shape and length. But if you think about it, this would be like taking a rubber band, lengthening it, until it adopts a new length. Because it has lost elasticity! Shouldn’t the goal be to gain elasticity?

Our joints need elasticity in order to protect themselves, to keep things controlled. The most flexible people in the world suffer debilitating injuries later in life due to permanent changes in tissue length. Loose connective tissue cannot protect the joints from hypermobile injuries.

Traditional static stretching deforms the plastic region of connective tissue. A balance of strength and relaxation is desired. Flexibility is a measure of increased range of motion due to an improved strength and corresponding release. Dynamic range of motion - the ability to move through, about, and around a specific joint - is more applicable to daily life. Dynamic mobility is not a measurement; it is function.

Soviet scientist and physician Alexander Bogomoletz once said “Man is as old as his connective tissues”. Editha Hearns wrote a book on the subject called: “You are as young as your spine.” The long and the short of it – no pun intended – is this: We cannot rely on tissue stretching for flexibility, because we will lose it. We must master the regulation of selective tension in order to gain dynamic strength. Without strength, there is no control, so what is the point?

The combination of a sudden stretch and muscular contraction can result in tearing tendons. A stretch on one side and a simultaneous contraction on the other is known as the stretch reflex. A muscle that is stretched by an external force too far or too fast will contract to oppose the stretch. This is obviously not healthy.

Before beginning dynamic strengthening exercises to develop plasticity, we must learn to regulate muscular tension. Tendons and ligaments are composed of collagen (lending tensile strength) and elastin (lending elasticity). As we age, our tissues endure an irreversible process of increasing collagen and decreasing elastin. Conventional static stretching does not prevent the connective tissues from stiffening.

If elasticity is a material’s ability to return to its original state following deformation after removing load, to increase elasticity of a tissue, we must apply a load to the tissue in a range of motion, then remove the load, after the initial stiffness ceases and before the tissue is permanently deformed so that the tissue returns to its original state. This stress increases the capacity for storage of elastic energy. Elastic energy is a fascinating concept because it has so much potential usefulness in everyday life. Think of the jungle cat: The balance of strength and elastic energy is a powerful combination. 

There is another characteristic that affects mobility: that is, viscosity. Think of honey versus water leaking out of a cup with a hole in the bottom. The rate of drainage is much different depending on the viscosity of the liquid. Likewise, flexibility is also speed specific. Temperature affects the rate of stretchability. Different tissues respond differently to various rates of loading. When loaded rapidly, they resist deformation moreso than if they are loaded slowly. Flexibility is speed specific. Therefore dynamic flexibility cannot be gained through static stretches. 

As we age, the collagen/elastin ratio changes in favour of collagen. With decreased integrity of tissue elasticity, connective tissue is more likely to snap. So it is not how far we can move in a particular direction that is important, but how strong our tissues are, how quickly they resolve deviations in movement and afford us mobile security - movement with strength. As a result, we must train for flexibility in motion, coordinating range of mobility at our activity's velocity.

We are mobile beings, and we should train that way.