Thinking on Stretch

......some back and forth thoughts with a clinician regarding what really happens when we "stretch"..........The process of developing movement through a required ROM has been something that I have been contemplating a bit lately. The idea that stretching "lengthens" a muscle in the setting of a gym or clinic is one I really haven't been able to buy into. From the little I have read on the subject the majority of any changes that occur are going to be directly due to a change in the nervous system and its input. In the absence of pain and the interest of moving more efficiently in sports I think that some form of training that targets increased ROM is advisable. The only way I know to add length to a muscle is adding sarcomeres in series. Also the amount of force required to impart a plastic deformation on connective tissue is fairly high (24-115kg). While in the clinic or weight room this level of force can be developed externally but it is highly unlikely that 100% of it is applied to the target tissue. (taken from https://ptjournal.apta.org/content/72/12/893.full.pdf)This is pretty much just a ramble to think "out loud" but I would be interested in any thoughts or opinions. If the nervous system is what dictates our limits in movement then what methods are going to communicate the idea that we need a bit more length in certain movements? And what will cause this to stick over time?

I am really not out of favor of putting a limb or joint system into a sustained passive tension. I say limb specifically because the tissue which is tensioned can be any combination of muscle, fascia, tendon, capsule. And within those "pieces," the constituency of the tissue is varied in terms of elastin and collagen, of course one of which is springy and stretchy, and the other is stiffer and gunky in response to stretch or tension.

I'm sure I'm rehashing a Best Of post from StrengthCoach.com as I delve into my thoughts.

I do not have much of a role for passive stretching in when someone is in a corrective mode. If the muscle or fasica is to blame for a lack of joint mobility, I don't think yanking on it more is not the way it's going to get longer. My assumption is that the lack of length is a protective mechanism from the brain, and trying to override this is poor form. Do we even know if this "short" muscle is short from visoelastic constituency that have no resting neural input or contractile components that do?How do you know what you're stretching or elongating?  How do you know your elongating what you want to elongate intra-muscularly?I'm a tremendous proponent of stretching of segments of good tissue quality for increasing excursion to gain more range in which to generate power. So this is not an anti-stretching rant. I'm actually on the opposite side of that research ticket. I don't question the power loss because if I have more length, I have a greater arc of motion in which to generate force over time, and by the laws of inertia, I actually think power is increased, not decreased. It's just at a different point in the retest.I think there can be tight with or without tone.If you hold a gun to my head, I would probably say muscles take a very long time to get short, and more than likely happen to untrained individuals.Folks that continue to explore their mobility through movement and mild loads should not experience loss of length.Now that doesn't mean passive stretching can not decrease tone. When research demonstrates a post-test of increased ROM after passive stretching, I look at that as a test. I'm not sure if we have an interpretation of the physiology. Does that placid expression of available mobility deliver the parasympathetic state that we may be looking for? Or is there a legimitate mechanical response?More importantly, if we try to follow that literature, are we gaining length through fibrotic tissue, adhesions, and triggers? Or are we just affecting the tissue around it?I am very much of the believe that non-manual therapy approaches can affect non-fibrotic tissue. But those areas of muscle that are triggered or fibrotic "have a mind of their own." I don't think mind tricks can affect them, be them DNS, Z-Health, or meditation, which is actually where I might position very similarly to long-duration low-load stretching.Think of gym floor mats. It is mostly black, but it is specked with color. The specs of color are fibrotic tissue that must be treated with manual therapy. But they make up a minute percentage of the whole piece (muscle). I think you can create a legitimate increase in flexibility measures by yanking on all the rest of the piece (black areas of the floor).I might suggest this is a long-term dysfunction.If we remove the specs and then go through integrated movements of proper progression, will we can explore joint mobility, new lengths, and neuromuscular control?Do we need to stretch? Maybe we are without holding it for long duration.I'd rather (more complicated, yes) get a limb max length that still shows joint integrity, and use other body parts' motion to drive the nervous system to release tone.What circumstances would have to occur for static stretching to be chosen above another option? If we are admitting that the majority of the issue is due to neural input why would a static stretch be applied to the structures that are limiting movement whatever they may be? My understanding of static stretching is that it is relying on the visco-elastic properties of the tissues and we are looking for a plastic deformation to occur.In an interesting little video I watched David Butler discussed the use of a mirror box and mentioned the fact that merely using this device is sometimes sufficient to restore some mobility.It's just a matter of what you call static stretching.Do I want to get into a position, and just stay there?  No, probably never.I want to get in and out for no longer than 2 seconds.Or I want to use creating tensions through the body's chains and slings to challenge the tone in that maximally lengthened and externally stable arm or leg.  If someone would want to call that static stretching, I think that's fair.For those that claim or support that stretching addresses plastic changes, I agree, but as I mentioned before, I think it creates I guess I can call it intramuscular relative compensatory flexibility.  There is fibrotic tissue that is not being lengthened by these "tried and true approaches."