Children and stretching

[TenTigers]

at what age is it safe to start children in stretching?
I searched the web and found that kids start stretching and gymnastics as early as eighteen months!
Anyone have any valid info? (valid, meaning not simply based on your personal opinion, unless you are a PT like TGY, or similar background)

[sanjuro_ronin]

Easy stretches ( ROM) can be done at any age but the high level one in gymnastics, well...
Lets be honest, competitive sports do NOT = doing what is healthiest.
Because children get LESS flexible as they get older, getting them young and keeping them flexible is the way to go for competitive gymnastics.

[Oso]

no valid info. sorry.

imo, kids don't really need to train MA till at least 7 anyways. at that point, i think any moderate stretching should be fine.

but, unless you are some sort of specialist (with degrees and/or training) I don't think any martial arts teacher should be pushing kids beyond thier comfort zone.

i had a student from 8-11 years of age who had really tight hamstrings. they didn't really ever loosen up. in class, i'd have her do 'toe touches', first on a book, then fingers to the floor, then knuckles, then fist...never got her to palms flat. but that took about 3 months. her mom, a dancer, wanted me to force her into stretches up to and including pushing her down...i said no.

[IronFist]

no valid info. sorry.

imo, kids don't really need to train MA till at least 7 anyways. at that point, i think any moderate stretching should be fine.

but, unless you are some sort of specialist (with degrees and/or training) I don't think any martial arts teacher should be pushing kids beyond thier comfort zone.

i had a student from 8-11 years of age who had really tight hamstrings. they didn't really ever loosen up. in class, i'd have her do 'toe touches', first on a book, then fingers to the floor, then knuckles, then fist...never got her to palms flat. but that took about 3 months. her mom, a dancer, wanted me to force her into stretches up to and including pushing her down...i said no.

Good for you.

Pushing down on someone doing a toe touch stretch would be horrible... especially considering that stretches the lower back more than the hamstrings, anyway.

[Drake]

I've been doing partner-assisted stretches for years... there's nothing wrong with them.

[Oso]

I've been doing partner-assisted stretches for years... there's nothing wrong with them.

as an adult, fine. your decision.

my point was that most martial arts teachers are NOT even remotely qualified to diagnose or treat any physiological issue PERIOD. Much less on a child. If you are of legal age and choose to participate in something that you may or may not be qualified to actually determine it's value/worth, then so be it.

in teaching children, including 'stretching', the most we should do is encourage progress.

[YouKnowWho]

We should always do dynamic stretching after static stretching.

[Fa Xing]

We should always do dynamic stretching after static stretching.

I would invest in a foam roller:

http://www.teamamericafitness.us/fitnessstore/images/80233.gif

This helps to loosen up adhesions, and enhance the muscle/tissue quality before any stretching is done.

Plus, the science is often leaning towards dynamic then static, which is generally
how I do it.


Acute Effects of Static versus Dynamic Stretching on Isometric Peak Torque, Electromyography, and Mechanomyography of the Biceps Femoris Muscle
Herda, Trent J1; Cramer, Joel T1; Ryan, Eric D1; McHugh, Malachy P2; Stout, Jeffrey R1

Abstract

The purpose of this study was to examine the acute effects of static versus dynamic stretching on peak torque (PT) and electromyographic (EMG), and mechanomyographic (MMG) amplitude of the biceps femoris muscle (BF) during isometric maximal voluntary contractions of the leg flexors at four different knee joint angles. Fourteen men ((mean ± SD) age, 25 ± 4 years) performed two isometric leg flexion maximal voluntary contractions at knee joint angles of 41°, 61°, 81°, and 101° below full leg extension. EMG (μV) and MMG (m·s-2) signals were recorded from the BF muscle while PT values (Nm) were sampled from an isokinetic dynamometer. The right hamstrings were stretched with either static (stretching time, 9.2 ± 0.4 minutes) or dynamic (9.1 ± 0.3 minutes) stretching exercises. Four repetitions of three static stretching exercises were held for 30 seconds each, whereas four sets of three dynamic stretching exercises were performed (12-15 repetitions) with each set lasting 30 seconds. PT decreased after the static stretching at 81° (p = 0.019) and 101° (p = 0.001) but not at other angles. PT did not change (p > 0.05) after the dynamic stretching. EMG amplitude remained unchanged after the static stretching (p > 0.05) but increased after the dynamic stretching at 101° (p < 0.001) and 81° (p < 0.001). MMG amplitude increased in response to the static stretching at 101° (p = 0.003), whereas the dynamic stretching increased MMG amplitude at all joint angles (p ≤ 0.05). These results suggested that the decreases in strength after the static stretching may have been the result of mechanical rather than neural mechanisms for the BF muscle. Overall, an acute bout of dynamic stretching may be less detrimental to muscle strength than static stretching for the hamstrings.

[Oso]

foam rollers rock. i wish i had the drive to torture myself with them more often. but, i don't think rolling yourself qualifies as stretching, more, as you say, break down lumpy, sticky spots...which may be more to the point than elongation.

@ you know who: i dunno. maybe. i have a lot of questions about stretching. as do a lot of people. and, no one seems to agree on the answer. I think that some stretching vs. 'too much' stretching is better. maybe possibly contrary to 'traditional' methods, we, as people, can be 'too' loose.

[/channeling] you know who but not 'YouKnowWho'

****, i crack myself up :D

but, back to the point: i don't believe that anyone on this board is certified or qualified to say WHY a child may or may not be abnormally flexible...maybe not even Chris (sorry, your alias is escaping me). Though, he is probably the only person here who comes close.

have your youth students go through 'normal' range of motion stretching, with some emphasis on improving ROM if they do seem 'short'. But, otherwise, leave it to the PT's and don't pressure them to be chinese wushu stars.

[Fa Xing]

foam rollers rock. i wish i had the drive to torture myself with them more often. but, i don't think rolling yourself qualifies as stretching, more, as you say, break down lumpy, sticky spots...which may be more to the point than elongation.

@ you know who: i dunno. maybe. i have a lot of questions about stretching. as do a lot of people. and, no one seems to agree on the answer. I think that some stretching vs. 'too much' stretching is better. maybe possibly contrary to 'traditional' methods, we, as people, can be 'too' loose.

[/channeling] you know who but not 'YouKnowWho'

****, i crack myself up :D

but, back to the point: i don't believe that anyone on this board is certified or qualified to say WHY a child may or may not be abnormally flexible...maybe not even Chris (sorry, your alias is escaping me). Though, he is probably the only person here who comes close.

have your youth students go through 'normal' range of motion stretching, with some emphasis on improving ROM if they do seem 'short'. But, otherwise, leave it to the PT's and don't pressure them to be chinese wushu stars.

I am a certified Strength and Conditioning coach, and a future chiropractic doctor :rolleyes: not be rude and toot my horn or whatever.

Plus I've stretched since I was 12 years old almost on a daily basis and have greatly retained my flexibility (I'm 29 now).

[Oso]

Easy stretches ( ROM) can be done at any age but the high level one in gymnastics, well...
Lets be honest, competitive sports do NOT = doing what is healthiest.
Because children get LESS flexible as they get older, getting them young and keeping them flexible is the way to go for competitive gymnastics.

****, missed this post.

what he said.

[Oso]

I am a certified Strength and Conditioning coach, and a future chiropractic doctor :rolleyes:

good for you. do you specialize in youth/pediatric strength and conditioning.

if not, then most probably (i could be wrong, if so, prove it) all of your literature probably focuses on college athletics and older age groups.

and, 'chiropractic doctor'? really? you're kidding me to throw that out.

[Fa Xing]

and, 'chiropractic doctor'? really? you're kidding me to throw that out.

Actually, I'm not and if you have some bull**** about how Chiropractics is "this or that" then I bet you need to some research.

Plus, a child's body is not really that much different from an adult's with exception of ossification. It is better to have a child stretch early on to maintain flexibility because as Sanjuro said they lose it the older they get, it averages about 10% per decade.

[Oso]

Actually, I'm not and if you have some bull**** about how Chiropractics is "this or that" then I bet you need to some research.

Plus, a child's body is not really that much different from an adult's with exception of ossification. It is better to have a child stretch early on to maintain flexibility because as Sanjuro said they lose it the older they get, it averages about 10% per decade.

oh, touched a nerve.

fine. stake your 'practice' on that belief.

as I said, prove that your studies have NOT been primarily on the adult body.

the point is that most of us don't KNOW. taking a field of data that exists for adults and projecting it onto children is a mistake. again, prove that you do KNOW exactly how a child should be pushed beyond normal ranges of motion.

i think the extremes of what is done to youth that participate in ballet, dance and gymnastics (which all make up modern wushu) are self evident in that you don't see any of them participating in the sport much beyond their 20's...cuz, they are wrecked.

pretty much the same as what we see happen to pro football players but we don't see the news coverage.

[YouKnowWho]

My daughter didn't do any stretching until she was 25 years old. Now she is more flexible than I could ever be.

http://www.youtube.com/watch?v=_0e4d6AEf9w

http://natashawang.com/

[Oso]

My daughter didn't do any stretching until she was 25 years old. Now she is more flexible than I could ever be.

http://www.youtube.com/watch?v=_0e4d6AEf9w

http://natashawang.com/

wow:)





1234567890

[sanjuro_ronin]

Flexibility can be developed, even to the extreme, at any age, the issue is WHY.
Arguably one needs only to be as flexible as one NEEDS to be, but for some being more so is quite natural ( like those born naturally fast or strong, some are born naturally flexible).

[taai gihk yahn]

however, just consider this: if u r trying to increase flexibility and do this by putingt an entire chain of structures under tension, where do u think is it going to actually "stretch"? will it b the structures that are hypomobile (that don't want to move), or the parts that are have already become hypermobile, the ones that move in excess in order to compensate for the lack of mobility elsewhere, and will just carry along the hypomobile segments with them as a unit?

of course, it's going to be the latter - the "weakest link" in the chain will be the first to move;

so, if u want to increase mobility at the parts that are hypomobile, u have to isolate them, so that the tension is specific to those structures; to isolate with that degree regquires either excellent proprioception on the part of the person doing it themselves or the person doing it to them - and when u do isolate hypomobile segments, the amount of movement through the stretch is actually minimal; if u r off even just a little, the force that u need to mobilize the area of hypomobility will hit the hypermobile regions surrounding it, and that's where u will get ur "stretch";

so, do u think that most people, especially kids, have that degree of ability to self-isolate? do u think most martial arts teachers have that ability? heck, i don't think most therapists are able to do this correctly...

for example, talk about stretching hamstrings - looking at the two pics below, which person is isolating HS and which person is actually nowhere near them? which person actually has more HS mobility?
http://www.osteoarthritisblog.com/wp-content/uploads/2010/12/hamstring_stretch-seated.jpg

http://turbofitnesssecrets.com/wp-content/uploads/2010/10/Lying-Hamstring-Stretch.jpg

one person is actually doing some really bad things to themselves that have nothing to do w HS; if u can't tell the difference, and if u can't figure out where the person not stretching HS is actually dumping the tensional forces and what structures they r actually putting into dysfunction, do u think that u r qualified to direct people in "stretching"?


the other thing to consider is, how functional actually, is passive stretching? just cranking on something either by yourself or having someone else do it doesn't make too much sense, because then u r changing structure without changing function (ability of muscular system to fire in a coordinated manner in context of the change in structure): which is why there is some thinking in the profession that suggests "stretching" (as opposed to warming up w movement) before an event (work out, game) not only does not confer advantage, it actually increases risk of injury;

the "cutting edge' thinking in the PT community is looking at ideas of "mobilization w movement" (PNF, muscle energy, Mulligan technique, etc.) - meaning that when u r working to increase mobility, u put the specific structure(s) under tension and then have the person move in various ways, in order to instantly coordinate the change in structure to a change in function; the idea of passive stretching is pretty much out of touch w the reality of how the body works (and FYI, this does not include yoga - yoga postures, even when held "statically", r actually quite dynamic, it's just not in the same manner that we usually think of it);

also, there is ample evidence that shows that much range of motion increase occurs bec of neuromuscular changes, that is, changes in muscle tone, as opposed to elongation of non-contractile structures (connective tissue); and much of this change in muscle tone leading to increased range can occur by actually not stretching, but by going into the direction or ease / restriction! (to see this principle in action, check out totalmotionrelease.com); when u do this sort of thing, u get profound and immediate changes that don't involve stretching at all

of course, if we r talking about actual restriction of connective tissue, then we r back to the above example of how to move the parts that don't want to move without moving the parts that want to do so excessively...

"stretching' correctly is difficult - u have to have a very precise knowedge of what structures u r putting under tension and how to align the body correctly; if one wants to abuse oneself, one can go right ahead, but if one is running a class and having kids do stretches without the correct knowledge, one may b doing them more harm than good...

[sanjuro_ronin]

however, just consider this: if u r trying to increase flexibility and do this by putingt an entire chain of structures under tension, where do u think is it going to actually "stretch"? will it b the structures that are hypomobile (that don't want to move), or the parts that are have already become hypermobile, the ones that move in excess in order to compensate for the lack of mobility elsewhere, and will just carry along the hypomobile segments with them as a unit?

of course, it's going to be the latter - the "weakest link" in the chain will be the first to move;

so, if u want to increase mobility at the parts that are hypomobile, u have to isolate them, so that the tension is specific to those structures; to isolate with that degree regquires either excellent proprioception on the part of the person doing it themselves or the person doing it to them - and when u do isolate hypomobile segments, the amount of movement through the stretch is actually minimal; if u r off even just a little, the force that u need to mobilize the area of hypomobility will hit the hypermobile regions surrounding it, and that's where u will get ur "stretch";

so, do u think that most people, especially kids, have that degree of ability to self-isolate? do u think most martial arts teachers have that ability? heck, i don't think most therapists are able to do this correctly...

for example, talk about stretching hamstrings - looking at the two pics below, which person is isolating HS and which person is actually nowhere near them? which person actually has more HS mobility?
http://www.osteoarthritisblog.com/wp-content/uploads/2010/12/hamstring_stretch-seated.jpg

http://turbofitnesssecrets.com/wp-content/uploads/2010/10/Lying-Hamstring-Stretch.jpg

one person is actually doing some really bad things to themselves that have nothing to do w HS; if u can't tell the difference, and if u can't figure out where the person not stretching HS is actually dumping the tensional forces and what structures they r actually putting into dysfunction, do u think that u r qualified to direct people in "stretching"?


the other thing to consider is, how functional actually, is passive stretching? just cranking on something either by yourself or having someone else do it doesn't make too much sense, because then u r changing structure without changing function (ability of muscular system to fire in a coordinated manner in context of the change in structure): which is why there is some thinking in the profession that suggests "stretching" (as opposed to warming up w movement) before an event (work out, game) not only does not confer advantage, it actually increases risk of injury;

the "cutting edge' thinking in the PT community is looking at ideas of "mobilization w movement" (PNF, muscle energy, Mulligan technique, etc.) - meaning that when u r working to increase mobility, u put the specific structure(s) under tension and then have the person move in various ways, in order to instantly coordinate the change in structure to a change in function; the idea of passive stretching is pretty much out of touch w the reality of how the body works (and FYI, this does not include yoga - yoga postures, even when held "statically", r actually quite dynamic, it's just not in the same manner that we usually think of it);

also, there is ample evidence that shows that much range of motion increase occurs bec of neuromuscular changes, that is, changes in muscle tone, as opposed to elongation of non-contractile structures (connective tissue); and much of this change in muscle tone leading to increased range can occur by actually not stretching, but by going into the direction or ease / restriction! (to see this principle in action, check out totalmotionrelease.com); when u do this sort of thing, u get profound and immediate changes that don't involve stretching at all

of course, if we r talking about actual restriction of connective tissue, then we r back to the above example of how to move the parts that don't want to move without moving the parts that want to do so excessively...

"stretching' correctly is difficult - u have to have a very precise knowedge of what structures u r putting under tension and how to align the body correctly; if one wants to abuse oneself, one can go right ahead, but if one is running a class and having kids do stretches without the correct knowledge, one may b doing them more harm than good...

The correct stretch is the bottom one I think.

[taai gihk yahn]

The correct stretch is the bottom one I think.

Why? And if so, what's the problem w the other one?

[sanjuro_ronin]

Why? And if so, what's the problem w the other one?

Problems with the first one are:
You aren't really stretching the Hammy, more like the lover back.
There is strain on the extended knee
Strain on the shoulder
The position of the bent leg seems to be to "open".
She seems to be reached with her hands and neck ( back rounded) as opposed to bringing her chest down with the back straight.
I am sure there's more...

[diego]

however, just consider this: if u r trying to increase flexibility and do this by putingt an entire chain of structures under tension, where do u think is it going to actually "stretch"? will it b the structures that are hypomobile (that don't want to move), or the parts that are have already become hypermobile, the ones that move in excess in order to compensate for the lack of mobility elsewhere, and will just carry along the hypomobile segments with them as a unit?

of course, it's going to be the latter - the "weakest link" in the chain will be the first to move;

so, if u want to increase mobility at the parts that are hypomobile, u have to isolate them, so that the tension is specific to those structures; to isolate with that degree regquires either excellent proprioception on the part of the person doing it themselves or the person doing it to them - and when u do isolate hypomobile segments, the amount of movement through the stretch is actually minimal; if u r off even just a little, the force that u need to mobilize the area of hypomobility will hit the hypermobile regions surrounding it, and that's where u will get ur "stretch";

so, do u think that most people, especially kids, have that degree of ability to self-isolate? do u think most martial arts teachers have that ability? heck, i don't think most therapists are able to do this correctly...

for example, talk about stretching hamstrings - looking at the two pics below, which person is isolating HS and which person is actually nowhere near them? which person actually has more HS mobility?
http://www.osteoarthritisblog.com/wp-content/uploads/2010/12/hamstring_stretch-seated.jpg

http://turbofitnesssecrets.com/wp-content/uploads/2010/10/Lying-Hamstring-Stretch.jpg

one person is actually doing some really bad things to themselves that have nothing to do w HS; if u can't tell the difference, and if u can't figure out where the person not stretching HS is actually dumping the tensional forces and what structures they r actually putting into dysfunction, do u think that u r qualified to direct people in "stretching"?


the other thing to consider is, how functional actually, is passive stretching? just cranking on something either by yourself or having someone else do it doesn't make too much sense, because then u r changing structure without changing function (ability of muscular system to fire in a coordinated manner in context of the change in structure): which is why there is some thinking in the profession that suggests "stretching" (as opposed to warming up w movement) before an event (work out, game) not only does not confer advantage, it actually increases risk of injury;

the "cutting edge' thinking in the PT community is looking at ideas of "mobilization w movement" (PNF, muscle energy, Mulligan technique, etc.) - meaning that when u r working to increase mobility, u put the specific structure(s) under tension and then have the person move in various ways, in order to instantly coordinate the change in structure to a change in function; the idea of passive stretching is pretty much out of touch w the reality of how the body works (and FYI, this does not include yoga - yoga postures, even when held "statically", r actually quite dynamic, it's just not in the same manner that we usually think of it);

also, there is ample evidence that shows that much range of motion increase occurs bec of neuromuscular changes, that is, changes in muscle tone, as opposed to elongation of non-contractile structures (connective tissue); and much of this change in muscle tone leading to increased range can occur by actually not stretching, but by going into the direction or ease / restriction! (to see this principle in action, check out totalmotionrelease.com); when u do this sort of thing, u get profound and immediate changes that don't involve stretching at all

of course, if we r talking about actual restriction of connective tissue, then we r back to the above example of how to move the parts that don't want to move without moving the parts that want to do so excessively...

"stretching' correctly is difficult - u have to have a very precise knowedge of what structures u r putting under tension and how to align the body correctly; if one wants to abuse oneself, one can go right ahead, but if one is running a class and having kids do stretches without the correct knowledge, one may b doing them more harm than good...

Off topic a little but this seems like a good thread to ask in since the topic relates to Physiology and Martial Arts...When you first start to practice holding static horse stance or various Plank postures why does the body start to tremble around the 30-90 second mark, like what's going on with the Nervous System?.

[taai gihk yahn]

Problems with the first one are:
You aren't really stretching the Hammy, more like the lover back.
There is strain on the extended knee
Strain on the shoulder
The position of the bent leg seems to be to "open".
She seems to be reached with her hands and neck ( back rounded) as opposed to bringing her chest down with the back straight.
I am sure there's more...

yep, that pretty much covers it; altho, in my estimation, I'd say she's actually not putting that much strain on low back, most of the tension looks mid to lower thoracic (basicaly the apex of the forward curve); however, the observation of the bent leg being "open" is, IMPO, a key one and spot on - it suggests marked hypomobility somewhere in the pelvis that she isn't managing, and is creating compensation elsewehere - if u notice her knee is pointing forwards as opposed to the other person's pointing backward - so she's actualy limited in hip "opening" (I personaly think she also has very tight lats from the look of things, and lats attach from arm to spine at T6 all the way down to iliac crests, sacrum and coccyx); another area that wud b of more concern to me is what she is doing to her upper cervical spine, vis a vis a a compression force into extension from C0 to C3 - u also c a lot of tension on the anterior neck structures; but overall, she's almost nowhere in regards to HS;

by contrast, the other pic u see the spine in alignment, the head relatively elongated off the trunk and trunk off pelvis, w a forward hinge at the hips (the first pic, the hip angle is very open - she's getting no mobility there at all) - this allows for the knee to be stable while the pelvis rotates anteriorly, which causes the proximal HS attachments at ischial tuberosities to move away from the knee (when top of pelvis rotates fwd, the bottom counter rotates backwards) - so basically HS are stabilized at the knee and are mobilized proximally via pelvic rotation; that way u take lumbar spine and anything else out of the equation;

also, a key indicator - the gal on the bottom is smiling, the other one looks miserable...and I wud bet $ gal #1 has digestive / "female" issues as well...

[taai gihk yahn]

Off topic a little but this seems like a good thread to ask in since the topic relates to Physiology and Martial Arts...When you first start to practice holding static horse stance or various Plank postures why does the body start to tremble around the 30-90 second mark, like what's going on with the Nervous System?.

it's called "phasic shakes" - basically u r using peripheral "long' (multi-joint) phasic muscles to hold urself instead of the tonic "core" ones (multifidi, e.g.); phasics r good at quick burst firing, not so good holding sustained contractions; so they start to fatigue and loose cross links, and so u get the shakes; when they fatigue, then the core stabilizers can kick in bec the nervous system can't use the phasics anymore - most people's core muscles r in a state of relative inhibition, so the brain wil only fire them when it runs out of other options - this is what happens when u have the shakes and then at some point they just seem to stop and u feel a lot stronger - u r now recruiting core muscles immediately;

of course, many people get injured before this happens, as the peripheral phasics r usually over worked and prone to tearing...

[Oso]

also, a key indicator - the gal on the bottom is smiling, the other one looks miserable...and I wud bet $ gal #1 has digestive / "female" issues as well...

lol, i was going to say something about that relative to which one would be more fun...as in, the smiling one.

[Vajramusti]

-------------------
yep, that pretty much covers it; altho, in my estimation, I'd say she's actually not putting that much strain on low back, most of the tension looks mid to lower thoracic (basicaly the apex of the forward curve); however, the observation of the bent leg being "open" is, IMPO, a key one and spot on - it suggests marked hypomobility somewhere in the pelvis that she isn't managing, and is creating compensation elsewehere - if u notice her knee is pointing forwards as opposed to the other person's pointing backward - so she's actualy limited in hip "opening" (I personaly think she also has very tight lats from the look of things, and lats attach from arm to spine at T6 all the way down to iliac crests, sacrum and coccyx); another area that wud b of more concern to me is what she is doing to her upper cervical spine, vis a vis a a compression force into extension from C0 to C3 - u also c a lot of tension on the anterior neck structures; but overall, she's almost nowhere in regards to HS;

by contrast, the other pic u see the spine in alignment, the head relatively elongated off the trunk and trunk off pelvis, w a forward hinge at the hips (the first pic, the hip angle is very open - she's getting no mobility there at all) - this allows for the knee to be stable while the pelvis rotates anteriorly, which causes the proximal HS attachments at ischial tuberosities to move away from the knee (when top of pelvis rotates fwd, the bottom counter rotates backwards) - so basically HS are stabilized at the knee and are mobilized proximally via pelvic rotation; that way u take lumbar spine and anything else out of the equation;

also, a key indicator - the gal on the bottom is smiling, the other one looks miserable...and I wud bet $ gal #1 has digestive / "female" issues as well...
--------------------------------------------------------------------------------------------------Thanks for the good discussion.

joy chaudhuri

[Vajramusti]

http://well.blogs.nytimes.com/2011/11/16/the-right-reasons-to-stretch-before-exercise/?ref=health

you might be interested in this article on stretching in yesterdays New York Times.

[sanjuro_ronin]

yep, that pretty much covers it; altho, in my estimation, I'd say she's actually not putting that much strain on low back, most of the tension looks mid to lower thoracic (basicaly the apex of the forward curve); however, the observation of the bent leg being "open" is, IMPO, a key one and spot on - it suggests marked hypomobility somewhere in the pelvis that she isn't managing, and is creating compensation elsewehere - if u notice her knee is pointing forwards as opposed to the other person's pointing backward - so she's actualy limited in hip "opening" (I personaly think she also has very tight lats from the look of things, and lats attach from arm to spine at T6 all the way down to iliac crests, sacrum and coccyx); another area that wud b of more concern to me is what she is doing to her upper cervical spine, vis a vis a a compression force into extension from C0 to C3 - u also c a lot of tension on the anterior neck structures; but overall, she's almost nowhere in regards to HS;

by contrast, the other pic u see the spine in alignment, the head relatively elongated off the trunk and trunk off pelvis, w a forward hinge at the hips (the first pic, the hip angle is very open - she's getting no mobility there at all) - this allows for the knee to be stable while the pelvis rotates anteriorly, which causes the proximal HS attachments at ischial tuberosities to move away from the knee (when top of pelvis rotates fwd, the bottom counter rotates backwards) - so basically HS are stabilized at the knee and are mobilized proximally via pelvic rotation; that way u take lumbar spine and anything else out of the equation;

also, a key indicator - the gal on the bottom is smiling, the other one looks miserable...and I wud bet $ gal #1 has digestive / "female" issues as well...

Yes, I agree in regards to the mid back thing.
I deduced that from my experience because when ever I used to do that stretch that way, those were the areas where I felt the "stretch".
Stretching seems to be one of those things that everyone THINKS they know how to do, but very few do correctly.
I have a few books on it, the various methods and such, including yoga and gymnastic geared stretches.
I have found that more is NOT better, that "best is best".
I have found that respect our natural flexibility and going beyond it ( if we have to) in a slow manner is best, I have also found that for "dynamic" physical movements that the majority should be dynamic stretches with static to "finish".

[diego]

it's called "phasic shakes" - basically u r using peripheral "long' (multi-joint) phasic muscles to hold urself instead of the tonic "core" ones (multifidi, e.g.); phasics r good at quick burst firing, not so good holding sustained contractions; so they start to fatigue and loose cross links, and so u get the shakes; when they fatigue, then the core stabilizers can kick in bec the nervous system can't use the phasics anymore - most people's core muscles r in a state of relative inhibition, so the brain wil only fire them when it runs out of other options - this is what happens when u have the shakes and then at some point they just seem to stop and u feel a lot stronger - u r now recruiting core muscles immediately;

of course, many people get injured before this happens, as the peripheral phasics r usually over worked and prone to tearing...

Thanks for the info.