Research's contributions to becoming flexible

[FenryrMKIII]

I just began my flexibility work using Stretch Therapy. 

Reading the fist post of the present discussion, a few things are not 100% clear and I would like to discuss them. Please find herebelow my understanding based on Stretch and Therapy and another method (RPG, SGA) that I began to use a few months ago and which is discussed herebelow.

The first post states that once no more gain can be made in ROM following a contract-relax, this means that one has reached restrictions in the structures of the body (I understand muscles, ligaments, fascia). So here one does not face restrictions due to the brain but indeed due to e.g. too short muscles. Therefore, structural changes must be made to overcome this limitation.
First question : This kind of changes, in my understanding, are therefore quite different to what is one the main focus of Stretch Therapy i.e. overcoming limitations imposed by the brain. Therefore, when one faces structural limitations (as opposed to brain limitations), are the principles applied by Stretch Therapy still the most efficient ? Also, these kind of limitations should still appear during anesthesia I suppose. I could not find a detailed study about that to clearly answer "are you 100% flexible when anesthesized". I would love to test that on myself or even try stretching when under diazepam. 

Then, In order to make further changes happen when facing structural limitations, the first post also states than then position near the maximum end range must be hold for some minutes.
This would be in accordance with another stretching method I have used , sadly only available in french or spanish i.e. "Stretching global actif" or SGA which is derived from the "Rééducation posturale globale" or RPG method. RPG is the base of the method but is therapeutic (with a focus on scoliosis treatment) while SGA is derived from the RPG but is more focussed toward stretching for healthy and sporty people. The father of both methods is Philippe Souchard and here is the website. 
This stretching method has many common principles with Stretch Therapy e.g. contract-relax, small intensity (they spoke about "100 grams force of contraction"), importance of proper breathing, consideration of neural reflexes. But also differ by some degree e.g. they only work with poses and not isolating stretches, they do not consider the brain to be important in flexibility but rather aim to increase the length of the muscles by increasing sarcomeres in series based on  Goldspink  experiences.

And here is a key difference and the second question : they (authors of RPG & SGA) advocate to only work on cold muscles because this increases the stretch effect. They state that working on hot muscles reduce the efficiency of the stretch because it increases the elasticity of the muscles i.e. less "plastic deformations" and therefore reduces sarcomeres increase. 
What is your opinion about that ? 

Thanks for your opinion and for your time

 

[Kit_L]

On 1/12/2017 at 1:00 AM, FenryrMKIII said:

They state that working on hot muscles reduce the efficiency of the stretch because it increases the elasticity of the muscles i.e. less "plastic deformations" and therefore reduces sarcomeres increase. 

Frankly, complete nonsense. Please personally try both ways (hot and cold) and report back. The difference is night and day, for some people. I would love to hear your personal experiences. Trying both is good ol' empirical science; once you try both, you will know, for yourself.

[Jonas W]

Petrofsky JS, Laymon M, Lee H. Effect of heat and cold on tendon flexibility and force to flex the human knee. Medical Science Monitor : International Medical Journal of Experimental and Clinical Research. 2013;19:661-667. doi:10.12659/MSM.889145.   Background It is commonly believed in medicine that using heat will increase the distensability and flexibility of soft tissue. If true, increased flexibility would be a positive factor to reduce injuries in sports. However, cold should have the opposite effect and is often used to treat sports injuries. This study was accomplished to quantify the effect of heat and cold on the force needed to flex the knee and laxness of the anterior and posterior cruciate ligaments. Material/Methods The present study examined 20 male and female subjects to determine if heat would increase extensibility of the anterior and posterior cruciate ligaments of the knee and reduce the force needed to flex the knee. Cold exposure was examined to see if it would have the opposite effect. There were 4 experiments in the series: The first was a room temperature series; the second was a series where cold was applied with an ice pack for 20 minutes; in the third, hydrocollator heat packs were applied for 20 minutes; and in the fourth, ThermaCare heat wraps were applied for 4 hours on the quadriceps and knee. Tendon extensibility was measured with a KT2000. The force for flexing the knee was measured by passive movement being applied (CPM) to the knee through 30° and the force required to move the leg was measured. Results The results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application. Conclusions Heat is beneficial in increasing muscle and ligament flexibility and may help reduce athletic injuries, but cold treatment may have the opposite effect. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3747018/

[Jonas W]

Rancour JL, Terry ME, Holmes C, Cipriani DJ. Superficial Precooling on a 4-Week Static Stretching Regimen: A Randomized Trial. Sports Health. 2010;2(5):433-436. doi:10.1177/1941738110374612.

Abstract

Background:

The influence of superficial precooling on range of motion (ROM) as part of a stretching program has not been extensively studied. It is not clear if the analgesic effect can benefit a stretching program.

Hypotheses:

Superficial precooling will result in greater gains in ROM as part of a stretching program, compared with stretching without a precooling intervention. Superficial precooling will also result in greater retention in ROM gains following cessation of stretching, compared with stretching without a precooling intervention.

Study Design:

Prospective randomized single-blind test-retest design.

Methods:

Twenty-nine participants were randomly assigned to 1 of 2 static stretching protocols: a standard protocol (n, 14; age, 24.6 ± 5.4 years) or a precool protocol (n, 15; age, 25.1 ± 7.3 years). These samples allowed for 80% power for statistical significance testing. Both groups performed static hamstring stretching daily for 4 weeks. The precool group applied ice to the hamstring for 10 minutes before stretching. Both groups stretched for 4 weeks and then stopped stretching for the last 4 weeks. Hip ROM measures were obtained each week for 8 weeks.

Results:

For the standard group, mean hip ROM increased from 71.4° ± 18.5° to 90.6° ± 20.5° and for the precool group, 71.5° ± 22.3° to 91.8° ± 20.9°. For the standard group, mean hip ROM decreased from 90.6° ± 20.5° to 83.9° ± 20.3° and for the precool group, 91.8° ± 20.9 to 85.0° ± 19.4°. There were no differences between groups at any time in the study (P > .05).

Conclusions:

Precooling had no beneficial effects on ROM or on retention of ROM.

Clinical Relevance:

Cold application, before stretching, does not provide any benefit to a stretching program.

Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445057/

[Emmet Louis]

In the above one about the pre cooling their application of pre cooling was incorrect to trigger an increase of ROM. 

I have some methods of using pre cooling that will result in an immediate and massive increase in ROM. Obviously then training this new ROM is needed to retain. Its interesting that you can get the opposite results when you know how.

[Jonas W]

21 minutes ago, Emmet Louis said:

In the above one about the pre cooling their application of pre cooling was incorrect to trigger an increase of ROM. 

I have some methods of using pre cooling that will result in an immediate and massive increase in ROM. Obviously then training this new ROM is needed to retain. Its interesting that you can get the opposite results when you know how.

Anything you can share? In most areas there's a discrepancy between clinical experience and research. A massive increase in ROM sounds really interesting.

[Kit_L]

On 5/29/2017 at 3:41 AM, Jonas W said:

Results

The results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application. Italics added by responder.

Problem is this has nothing to do with developing flexibility of the sort we are interested in here—and in general we would discourage a lengthening of these exact same tissues. Further, I do not believe that this study's conclusions can be generalised to the whole body. I will create a new thread for this topic, because this has gone OT, I feel.

[Jonas W]

8 hours ago, Kit_L said:

Problem is this has nothing to do with developing flexibility of the sort we are interested in here—and in general we would discourage a lengthening of these exact same tissues. Further, I do not believe that this study's conclusions can be generalised to the whole body. I will create a new thread for this topic, because this has gone OT, I feel.

 

I agree with the sentiment… to a certain extent. The study could be used in a completely different conversation (like ACL rehab or something), but despite the interest in this sort of modality (heat and stretching), there seems to be a lack of research on the area. But if this is sort of off-topic, sorry. There are some studies, but they differ in quality (as is the case with most study areas).

 

Even though a ligament is not a muscle, it still consists of the same material as tendons (minus the neural component, like Golgi tendon organs, although they still have proprioceptive properties), albeit tendons have more collagen, etc.

 

As for the study itself, the authors make some (in my opinion) relevant reflections.

 

On the lack of research on the effect of heat on muscle stretching/flexibility:

“Heat is very commonly used before exercise [9]. One advantage is that by increasing tissue metabolism the muscle is prepared for the metabolic challenge of exercise [9,10]. Heat also increases glycogen resynthesis and muscle recovery [10]. Heat is also cited as increasing flexibility and thus reducing the chance of injury, and reducing energy cost of muscle contraction by reducing internal friction [11,12]. Internal energy costs are reduced by warming muscle, but many of these studies have been done in animals and very few in humans. There is only limited evidence that heat helps tissue stretching in humans. Further, when heat is used, there is no previous evidence of the effects of heat on the tendon or muscle itself, commonly referred to as the series and parallel elastic components in muscle [13].”

 

On the lack of research on tendons and ligaments:

“While there is a consensus on the use of heat for increasing ligament and muscle stretching prior to exercise as a means of reducing injury [36], there is little evidence that this really works. Logically, since ligaments and tendons are elastic structures, they should be more flexible with heat. Increasing temperature increases flexibility of knee ligaments (anterior and posterior cruciate) and there is a substantial change in tissue elasticity.”

 

There are some studies however.

 

Draper DO1, Castro JL, Feland B, Schulthies S, Eggett D. Shortwave diathermy and prolonged stretching increase hamstring flexibility more than prolonged stretching alone.J Orthop Sports Phys Ther. 2004 Jan;34(1):13-20.

 

Excerpt:

METHODS AND MEASURES:

Thirty college-age students (mean age, 21.5 years) with tight hamstrings (inability to achieve greater than 160 degrees knee extension at 90 degrees hip flexion) participated. Subjects were assigned to 1 of 3 groups: diathermy and stretch, sham diathermy and stretch, and control). Range of motion was recorded before and after each treatment for 5 days and on day 8. A straight leg-raise stretch was performed using a mechanical apparatus. Subjects in the diathermy-and-stretch group received 10 minutes of diathermy (distal hamstrings) followed by 5 minutes of simultaneous diathermy and stretch, followed by 5 minutes of stretching only. Subjects in the sham-diathermy-and-stretch group followed the same protocol, but with the diathermy unit turned off. Subjects in the control group lay on the table for 20 minutes. Data were analyzed using an ANOVA and post hoc t tests.

 

RESULTS:

Mean (+/- pooled SE) increases in knee extension after 5 days were 15.8 degrees 2.2 degrees for the diathermy-and-stretch group, 5.2 degrees +/- 2.2 degrees for the sham-diathermy-and-stretch group, and -0.3 degrees +/- 2.2 degrees for the control group. Seventy-two hours after the last treatment, the diathermy-and-stretch group lost 1.9 degrees +/- 2.2 degrees, the sham-diathermy-and-stretch group lost 3.0 degrees +/- 2.2 degrees, and the control group changed -0.4 degrees +/- 2.2 degrees.

 

It would be interesting to compare externally applied heat (sauna, diathermy, etc) compared to internally increased heat through cardio or something similar.

 

Here’s a study that found the opposite results (a pretty old study tbh):

Brodowicz GR, Welsh R, Wallis J. Comparison of Stretching with Ice, Stretching with Heat, or Stretching Alone on Hamstring Flexibility. Journal of Athletic Training. 1996;31(4):324-327.

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1318916/pdf/jathtrain00020-0038.pdf

 

This study only evaluated the effects of one single stretch session. There they used hot packs vs bags with crushed ice. They did the modified hurdler’s stretch and sit-and-reach, 3 minutes each, 2 single- and 2 double-leg static stretches. Total stretching time: 20 minutes.

 

They also discuss previous research and the conflicting results. There doesn’t seem to be much consensus about what a good stretching regime with heat vs cold application would be in a study. Time, dosage, etc?

 

Some reflections from the authors as to why cold might help induce increased flexibility immediately in a stretch includes:

• Diminished proprioceptive feedback?

• Depression of the stretch reflex?

• Effects on muscle spasms and/or pain sensation? This one is further pointed out in a study by Park et al.

 

Park K, Kwon O, Weon J, Choung S, Kim S. Comparison of the Effects of Local Cryotherapy and Passive Cross-Body Stretch on Extensibility in Subjects with Posterior Shoulder Tightness. Journal of Sports Science & Medicine. 2014;13(1):84-90.

 

That shoulder study (doing 6 sets x 30 seconds of stretching) summarized their findings as:

• Local cryotherapy (LC) decreased the uncomfortable stretch sensation, and increased the pressure pain threshold (PPT) of infraspinatus and posterior deltoid muscles in subjects with posterior shoulder tightness.
• Decreased stretch sensation by LC without passive stretching could improve the passive and active ROM of internal rotation and horizontal adduction in subjects with posterior shoulder tightness, similar to cross-body stretch.
• LC can be an alternative method to increase extensibility when individuals with posterior shoulder tightness have high stretch sensitivity and low PPT in the infraspinatus and posterior deltoid muscles.

 

Anyway, that's some related research on the subject. There will always be more research some day in the future... with hopefully better designs and so on. Sorry if my reply is a structural mess.

 

[Jim Pickles]

Some thoughts on a contentious and confusing topic (made more confusing because many different paradigms and goals seem to be being lumped together):

1. Most people agree that heat will allow more immediate flexibility. The heat in different cases has been applied internally by exercise or externally by hot baths. Some of this increased flexibility at least will be due to increased extensibility of the fascia, since we expect this structure to be highly responsive to temperature.

2. Does heat in itself (apart from other factors) allow better long-term gains in flexibility? Not known. One might expect that it would, if heat allows a greater stretch in each stretch session, then the tissues may well accommodate long-term to this newer range.

3. The idea that cold increases stretch, may arise where the cold dulls sensations from the part being stretched, thereby dulling the apprehension reflex, which inhibits stretching.

4. The idea that cold, by reducing the amount of stretch and therefore increasing the force on a muscle, could enhance the long-term gains in flexibility seems to me to be strange, but you never know till it has been tested. If the limit is fascia, then one would expect that cold would lead to less stretch overall, and therefore less force on the muscle (since muscle and some of the fascia are mechanically in parallel), and less adapatation to stretch. If the limit is muscle, then cold might lead to a greater force. But why not just pull harder anyway, to get the same high force? A non-sequitur, but in such a complex area, you never know till its been tested directly.

Jim.

[AlexanderEgebak]

It is not necessarily the heat or cold itself that causes increased or decreased range of motion.

All tissue have receptors that informs the brain about what is going on. Sometimes the brain notices the signal, sometimes not. When the brain asserts the information it interprets it as either positive or negative influence. The output of the brain if negative can be pain and/or tension, if positive a reduction of this. This mechanism will large explain why both heat and cold applied to tissues can increase flexibility; because it is interpreted as something positive.

We know that our beliefs about either heat or cold (and the context in which they are applied) various from person to person, and that explain why people react differently to the stimuli (many pain studies out there). However, the general population interprets heat as something positive and cold as something negative. To complicate matters even more the context can alter the situation so much that people change their negative or positive expectations and therefore react differently; good studies will have uniformed their methods and designed their studies cleverly to reduce this (which essentially is a placebo or nocebo effect) influence.

When both heat and cold works well to increase flexibility I largely suspect a contextual factor of a greater significance. Especially with regards to applying cold because the evidence out there is so solid that one easily can conclude that your autonomous nerve system reacts to cold as a threat, mostly.

[nick_kuchedav]

On 5/29/2017 at 3:35 PM, Emmet Louis said:

In the above one about the pre cooling their application of pre cooling was incorrect to trigger an increase of ROM. 

I have some methods of using pre cooling that will result in an immediate and massive increase in ROM. Obviously then training this new ROM is needed to retain. Its interesting that you can get the opposite results when you know how.

Hi @Emmet Louis, would you share some of pre cooling methods, that increase ROM?