Thursday, February 24, 2011

Do We Need to Stretch?

Stretching, the most common form of warming up, is not an effective way of lengthening muscle tissue. In order to add actual length to a muscle you’d have to stretch hourly, every day, for a looong time. Stretching may yet have value as a manner of increasing awareness of movement options. But, do we need to stretch?

There are many ways to increase your movement repertoire besides stretching. I call these methods of movement variability training. I think that much of the reported benefits of many popular movement methods, like pilates and yoga to name a couple, work at the level of movement variability.

Personally, I find showing people how to move into and out of positions that are unfamiliar to them (novel movements) with control and awareness is a great way to improve movement repertoires.

What’s unique about stretching? Sometimes it is done more effectively (by which I mean taken into further or different ranges of movement) when done passively. In general, it is my view that self efficacy should be encouraged whenever possible. So, stretching that requires the assistance of another is not optimal in this regard.

Sometimes we need help, though. And I’ve nothing against borrowing the hands of another to get moving when you’re stuck in a rut. After all, that’s part of what I do for people when necessary.

There are ways of stretching oneself that get around the self efficacy problem. Stretching also often feels “good” and I see nothing wrong with doing something for yourself that is pleasant, even if it is not necessary.

We may at times “need” to improve our movement repertoire and while stretching is one way to achieve this, it is not the only way. My opinion is that the “best” ways of improving movement repertoires are through methods that can be done successfully and safely without assistance once learned and are done without any wild belief systems attached to them. Stretching may fit the bill, and it may not depending on your situation.


Lauren said...

I was under the impression that stretching was to increase length of connective tissue, not muscle. By causing the collagen fibers in connective tissue to reach a new resting length, your muscle spindles and golgi tendon organs adopt a lower threshold to a length where they would previously have exhibited autogenic inhibition of the muscle.

Cory Blickenstaff said...

Thanks for chiming in, Lauren.

Reaching a new resting length is what is in question. Any immediate gains in length seen with stretching, whether they be through inhibitory mechanisms or tissue "creep" are temporary (I believe 4 hours is the length of temporary, if I recall correctly). To add lasting length to a muscle, we need addition of sarcomeres, the links in the chain of muscle. This requires long term exposure to lengthening input, thus my every hour of every day for a loooong time statement.

Any benefit seen at the level of collagen fibers are best considered in the realm of scar tissue remodeling, and while an active scar formation process may be more likely to respond to stretching favorably with less exposure, this is likely to be associated more with an alingment of collegen fibers and alterations in the inflammatory response moreso than an addition of actual length, unless of course the exposure is near constant.

Lauren said...

If the collagen matrix is expanded, and then remodels in an orderly parallel fashion (assuming we are talking about type 2 collagen), it shouldn't form scar tissue. Also, whether stretching functions to increase actual sarcomere length (which I also doubt) or to decrease the sensory threshold of stretch/tension receptors, isn't it good either way? Obviously hypermobility brings on a whole new set of problems, but it seems as though patients (myself included) benefit from increasing ROM in hypomobile areaa via stretching exercises.

Cory Blickenstaff said...

I'm not discounting that there is value in stretching, but I am questioning what that value is derived from. It is clear that any changes seen in ROM have nothing to do with muscle length. As you say, any change likely is coming from receptor sensitivity alteration.

See my previous post here:

My point is that, while stretching may be a useful method, it is not the only way to skin a cat, so to speak. Especially considering that any enduring effect is not due to effects on muscle length.