“Common wisdom is generally neither common nor wise”
–John Kenneth Galbraith
“Justifying improved practice on scientific evidence is a dynamic process. With new evidence, the foundation will change…Be prepared to challenge current thoughts and rethink currently accepted practices.”
Over the past several years, there has been an increasing level of controversy regarding stretching and its role in health, athletics, injury prevention, rehabilitation and back health. The amount of information out there is vast and often conflicting.
Some of the most recent controlled studies have found that passive (“static”) stretching—which requires no voluntary muscle activity—prior to training does not reduce or prevent injuries. In fact, it may have the opposite effect. It has been shown that less force is needed to rupture “stretchy” muscle than “stiff” muscle. (Voluntary muscles, also called skeletal muscles, are the ones that require some level of intent to move them: they move the bones, as in moving the arms or legs. These are different from involuntary muscles, which are primarily stabilizing, as in the postural muscles of the spine, which keep you upright and stable).
This does not mean that “stiff” muscles are good, and that we shouldn’t implement stretching into our routines. What it does mean is that we need to pay attention to “dynamic flexibility”, the ability to move joints through a range of motion during active movement with strength as a key component requiring voluntary muscle involvement.
Another very important piece is that we need to pay attention to the fact that we are not a conglomeration of distinct and separate segments, that flexibility and strength is a whole body, continuous necessity, from the soles of our feet to the top of our heads. Each part of our body has a part in supporting the body as a whole. Any part of our bodies that do not have flexibility and strength is a weak link in the chain, and can be injured or cause injury in some related part of the body.
In every sport, indeed, in every movement, mobility is a requirement, but loose joints without precisely controlled strength are unstable. This decreases such things as strength, balance and reaction time and increases the likelihood of subsequent injury. A reduction in strength or performance is clearly not what most people are looking for be they athlete, laborer, or weekend gardener.
Studies have shown that skeletal muscle damage can occur when stretched only 20% beyond its resting length. There is evidence of this damage hours after a bout of stretching, which has led scientists to conclude that stretching causes delayed-onset muscle soreness.
Dr. Ben Benjamin presents an explanation as to why prolonged periods of static stretching (60 seconds) are problematic. This is that it initiates what is called the “stretch reflex”, a defensive mechanism designed to prevent muscles from stretching too far. In response to over-stretching the muscle reflexively contracts, which creates tension and pulling on the tendons and ligaments at the joints which can reduce the stiffness they must have in order to stabilize the joints.
One of the major issues people face is maintaining and/or regaining back health. According to Stuart McGill, Ph.D., one of the world’s leading researchers of spinal mechanics and spinal health, there are no studies that have shown that working to increase back flexibility increases performance or healing. He goes on to explain that back flexibility is prescriptive on an individual basis, but not as a general prescriptive requirement to rehabilitate a bad back or maintain good back health. But strength endurance training is necessary for both.
In conclusion, the commonly assumed wisdom and perception of stretching as a panacea for pain and injury reduction, back health issues and performance improvement does not meet scientific reality. Dynamic warm-ups and strength building using ranges of motion, as well as whole body exercises that connect and work through the whole body to develop functional ranges of motion, will substantially contribute to function, performance and injury reduction.
–with thanks to Michael Reams, of the Rolf Institute of Structural Integration