Stretching is a broad topic. There are several elements involved when evaluating the mechanisms of flexibility and trying to create the change a client/athlete desire. Ultimately the method of implementation to improve someone’s flexibility is going to be dictated by the objective. Why are you stretching in the first place? Do you know why you’re tight to begin with? Do you understand the difference in active vs passive ranges of motion; or that more range of motion is not always a good thing?
We’ve all been taught that stretching prevents injuries and that we need to stretch before activity. Stretching has seemingly become a tradition that continues to be passed down from generation to generation. We learned to stretch from our coaches and gym teachers, and the cycle continues to repeat itself. But what is happening when we stretch and is it appropriate for our goals at that moment in time?
When we stretch, our goal is to lengthen a muscle. We stretch in an effort to make the muscle more flexible and improve its range of motion. However, for a muscle to improve its range of motion, the muscle that you are trying to lengthen must first relax. Relaxation is key to lengthening. Once a muscle is relaxed, it can then be moved into a new, lengthened position.
Your typical pre-game/prehab static stretching session isn’t accomplishing this. The low level of afferent feedback isn’t enough to cause significant changes in the viscoelasticity of the muscle creating a lengthened state. It simply isn’t enough time. Its more of a placebo effect.
The effects of stretching on the viscoelasticity of a muscle are short lived. Thus, stretching doesn’t make significant change to muscle. Improvements in flexibility are due more to a STRETCH TOLERANCE rather than change in the physical state of the tissue. (Spinea)
It will however increase the activity of something called a muscle spindle. Within each of our muscles lies a nervous system receptor called a muscle spindle. This muscle spindle can be stretched and compressed, similar to a slinky. As the length of a muscle begins to change, the muscle spindle will begin to fire (or turn on) causing contraction in the muscle. This reaction is called the stretch reflex.
This stretch reflex is a protective mechanism that is designed to prevent our muscles from pulling and tearing. So, the result is you trying to pull a muscle to its maximum length (stretch it), while the muscle fibers are tightened. This is similar to trying to stretch a towel beyond its maximal length...it’s not going to happen unless the towel rips.
As you continue to reach for that extra range of motion, the stretch actually comes from connective tissues as they begin to weaken. As you continue with repetitive sets, you are essentially setting yourself up for injury by weakening these extremely important connective tissues.
Research shows that there is tremendous amount of evidence showing that the articular system is intimately connected to the spindle system (Spinea).
After you are done stretching, there is what we call a “refractory period” that occurs. During this period, the exact opposite of what was originally occurring in the tissue occurs. So, if contraction occurred during the stretch, what is going to occur afterwards? You guessed correctly, no contraction! So, as you are trying to workout, run, jump etc., the contractions that are needed to help propel your body are less than they were before you stretched.
This refractory period is a problem because it significantly decreases your ability to create and absorb force. When the muscle(s) are unable to absorb force, the force transfers into the surrounding connective tissue and will eventually result in injury.
So, with this information, how are we supposed to increase our range of motion and improve our flexibility? There are two methods that we recommend that best put this knowledge to use. The first method is contract/release techniques. This is what most know as Proprioceptive Neuromuscular Facilitation (PNF). PNF is great, however leaves open the possibility of developing passive range of motion without active control. After the range of motion is created it’s important that it be maintained. This can be done through a variety of hovers, lift offs, passive range holds etc.
The second method is positional isometrics. Positional isometrics, when performed properly, not only lengthen the targeted muscles, but preserve the health of the tendons and ligaments. This subsequently reduces your chance of injury. They also increase blood flow and refuel the muscle much more efficiently allowing you to recover faster. To learn more about isometrics and how we implement them read our prior article on isometrics.
I’m hopeful this article providers the reader a better understanding of the mechanisms that occur during stretching, and how broad-based prescription of static stretching is not necessarily the best course of action. As we stated at the beginning of the article, the course of action for improvements in flexibility should be dictated by the objective.
John Nelson Founder/Director ELP