Recently I wrote an article HERE and HERE about the physiology of stretching, and whether or not we really need static stretching (holding a stretch for a prolonged period of time) in our training programs. The first blog covers the hierarchy of moving with proper mobility (controlling your range of motion), and the second covers the physiology behind stretching (are muscles really being “stretched”?). I also covered the importance of dynamic stretching techniques in these articles and whether or not we really need them.
With new research coming out of the Journal of Strength and Conditioning by Freitas et al, the theories I believed in are at question. Although the study was on “high –intensity stretching,” or stretching held for greater than 2 minutes (almost 6 minutes in this particular instance), there is still a lot to be said on what is happening to the actual muscle architecture. If you missed my previous blogs on stretching or don’t have time to read the other links, basically the findings were that muscle architecture CANNOT change with stretching, and the reason that stretching increases range of motion around a particular joint is due to increasing our pain tolerance to that particular range of motion. During this aforementioned study by Freitas, they found that an 8 week assisted stretching program changed pennation angle of the biceps femoris (most lateral hamstring muscle) as well as increasing the muscle fascicle length (the fascicle is bundle of skeletal muscle – see below).
This is contrary to the previous belief that muscles cannot lengthen. So does this mean that we should have someone stretch our hamstrings to make them longer? In most cases no, and I’ll tell you why:
1. Your muscle may not need more lengthening (and is already holding on for dear life)
There is a given amount of stretch our muscle can take before it actually strains or tears completely. It’s just like a rubber band; stretch it too far and it will snap. You may already be here without knowing it, and actually just require soft tissue work or core stability, which gets me into my next two points.
2. Core stability may really be your issue
I covered this topic HERE regarding core stability and hamstring length. If your core (the muscles between the top of the hips and bottom of the ribcage including the obliques, diaphragm, and front abs) is imbalanced from front to back (not neutral) meaning that the front abs are in more of a lengthened position than the low back muscles in most cases, this will effect how much range of motion you have at your hips and shoulders. Here’s an example below on core instability effect on hamstring stretching. You can see int he illustration that in this neutral position of the core I am able to get into a deep stretch, compared to if I had lumbar extension.
3. Your mobility may be restricted due to muscle soreness
If stretching means increasing our pain tolerance into certain ranges of motion, muscle soreness can be a culprit in what can create more pain and thus less range of motion.
4. Only one type of stretching was used in the stretching protocol
Would other stretching protocols produce similar results or better?
5. Ease of application
Partner assisted 6 minute static stretching by a trained professional can cost you anywhere from $30-60. Is this the best use of time? I do believe that assisted stretching can have a ton of benefits, but do you really need to focus on one area for 6 minutes?
6. You may need soft tissue work to turn your muscle “off”
Even if we are increasing muscle fascicle length overrall, which areas are getting lengthened most? Wouldn’t a better idea be to turn “off” muscles within the fascicle that are kept “on” thru inhibition of the golgi tendon organ and muscle spindles thru soft tissue work?
I’m sticking to my guns here that the psychology of stretching is paramount in the hierarchy of flexibility. Lengthening the muscle obviously works as this new research points out, but for the 6 reasons above I think partner assisted static stretching for 6 minutes is a misuse of time and not as efficient as a well rounded flexibility routine that includes stability work as well as soft tissue work.