Teaching Restorative Exercise (TM)

Recently I have been asked what my experience teaching RES (TM) is and why it works for some and not others and because I thought my answer would interest other people as well, here it is:

My experience with teaching RES(TM) is confined to my own experience and my friends and family. I taught a little while I was on the Wholebody alignment course, but the reason I stopped quite soon, was mainly that I didn't feel I knew enough of why we are doing what we learn in RES(TM) and about how to evalute it on the individual.

I am sure there are a lot of people out there who will benefit from RES(TM), but mainly because there are very many people out there. Why I think it works for some and not other is, that Katy Bowman has made a diagnosis of society and this will be true for some but not for other. She has concluded in the RES(TM) course that:

- People don't move enough

- If people move they move in the wrong way (walking in alignment is the right way) Katy makes some expections like climbing, but I don't know why, because climbing has side effects if done wrongly or in excess (finger joint problems, excessive kyphosis etc.)

- People sit too much and therefore have short hamstrings.

- People sit too much and don't walk enough and therefore have weak outer thigh muscles and gluets

- People sit too much and work on computer and drive too much and therefore have short chest muscles and hyper-kyphosis.

- People wear shoes too much and therefore have lost nerve connection and mobility in the foot.

- People wear high heels too much and therefore have forefoot problems and short calves.

- Peoples muscles are generally too short and therefore circulation is below optimal

- People with short calves and hamstrings and weak gluets and outer thigh have a mis-aligned pelvis and therefore pelivc floor issues

etc.

There are more but I think these are some of the main. Some of the conclusions above are strong points in that they are well researched or have a clear physical cause and others are weaker - a little less well researched. Katy covers some common causes that affect alighment, but there are many more and a lot of them didn't make it into the RES (TM) course and there is no real definition of what is in what is out and why.

Now if you fall in most of the above categories you are more likely to feel the benefits and with X billion people on this planet this will work for quite a few. I personally have found by going to a fascial stretch therapist and sports and rehabilitation PT that my gluets and outer thighs are too strong and RES exercises focus on the wrong areas for me. Also hamstring stretches are not great for me. My main misalignment is left/right imbalance, which is not really well covered in the course eventhough it affects also many people.

I found with friends and family that some of RES (TM) worked and some didn't. I found there were quite a few expections to the above diagnosis such as my sister likes to wear heels but has some of the best toe mobility I know even compared to my little children.

Some of the relief has been temporary through RES(TM) stretching and I think this area had the greatest success. RES(TM) seems to work well when is used as a tool to release tension.

The other area where being aware as in the RES(TM) method works well, in my experience, is when someone is in pain. In these cases there is already a signal from brain to body to stop the pain and if re-alignment can help them get out of pain, then it is well worth being aware of how to do this. This works for my mum, eventhough what she is doing to get out of her lower back pain is not a RES(TM) exercise or alignment adjustment but something else I noticed with her. Staying out of pain is a great motivator for behavioural changes.

Where is RES (TM) doesn't work so well is for exceptions, and because there are so many people on this planet, there will be many. If I or my sister focus on the aligment points that Katy brings forward, we are not focusing on the areas that are weak in us but the areas Katy thinks are weak in everyone. My next move now is to learn or use a method that is able to give me very specific individual advice (and I could kick myself for not doing this first).

The other problem with RES (TM) is the requirement to be aware of your alignment and movement as much as possible. The problem with this are:

As described above they may be the wrong alignment point to focus on. But mainly it is just not possible to be aware of something for a significant continious amount of time. Even Katy Bowman when walking at the RES week, and not being aware, still turns her feet out. How many years will it take for the alignment to stick, if even Katy Bowman is still reverting to previous patterns when not being aware? But even if you were able to keep your awareness with alignment all the time, you will miss other signals from your body or environment that may be more important.

I can see two non-intrusive ways to change your alignment:

1. You are aware of your alignment and the alignment that is optimal and try and change your alignment to be in an optimal state by consciously changing it and keep changing it as much as possible. This way your body will adapt to the new optimal alignment and your muscles will adapt and restrengthen to aid the new optimal alignment. This requires a lot of being aware and therefore long periods of practice. I wonder if one is able to be aware a significant amount of time to cause change. But if you can get it to work, you can get all the muscles just at the right length and strength and balanced. Main caveat of this method is that you need to know what your own optimal alignment state is. I think of this as the mental cast method.

2. You can find out which muscles are strong and which are weak, which are long and which are short and try and balance the function of your muscles by isolating the muscles and retraining them to be more balanced. This tends to be a faster method as you can strenghten and lengthen muscles specifically and balance opposing muscles pairs. You can work with joint mobility and try and balance the muscles around a joint for best results. So you work on the muscles/fascia/joints first and the result is your optimal alignment as defined by your balanced muscle set up. The main caveat of this method is that you need to know, what each muscles/joint is supposed to be doing and how they are supposed to interact and with which set-up you get the best, least degenerative result. You don't have to be aware of you alignment. You concentrate on doing your re-balacing and the body alignment will follow.

RES (TM) is a combination of the two with lots of the first and some of the second. The bits of the second method being non-specific to the person though.

I am trying the second method now with Fascial Stretch Therapy (FST). I went to a session last week and after working on my hip for an hour, I walked very differently and I could feel my feet working differently, in a way I have been trying to get them to work for a while with RES (TM). But this has only been one session, so I will see how I progress. FST says that the results are only temporary and we'll see if it's more like a massage you need to have once in a while to reset you.

How sane is sane

I am still working furiously on the Think again! Coursera course, trying to finish the material in time for a certificate, yeah!

In one of the exercises I came across an example of an unsound argument that reminded me of the article I read for the Restorative Exercise course called "How sane is sane" and it helped me understand, why the article did not quite gel with me. So this is for Restorative Exercise fellows again.

In the article, the author questions if we are not all mentally ill as we have similar ways of reacting to the outside word, as people, who are being labelled mentally ill, but maybe we are better at hiding them or controlling our strange behaviours. The article goes through a list of people with severe to moderate mental problems and compares them to similar everyday behaviour. The article concluding that we should not look for the illness in anyone but health. I agree that finding the good bits in anyone is a great starting point for recovery/treatmnet and labeling patients with their illnesses may not be productive (I am absolutely no expert in this field and have no experience, by the way). I was a little worried about the fact why generally more accepted behaviour is suggested to be equal to very unusual behaviour, just because it is similar and but happens less often.

While working on the Think again! course, I was reading the following argument and we were asked to looked at why arguments go wrong or become unsound or invalid.

"Consider the following argument: “‘Mental illness’ is just a phrase that the medical establishment uses to label people who do very strange things frequently. But each one of us does very strange things at least some of the time. And there’s no important difference between someone who does very strange things some of the time and someone else who does very strange things just a little bit more of the time. So there is no important difference between mentally ill people and everyone else.”

The exercise asked us to find the reason why this argument is not sound and the answer is:

"The correct answer is “(a) conceptual slippery slope argument.”

  A conceptual slippery slope argument is an unsound argument, which claims that, since a series of particular actions cannot change the quality of a certain thing, there is no real difference between cases that have that quality and cases that do not. Typically, the problem with a conceptual slippery slope argument is that its second premise claims that something is not a matter of degree, when in fact it is a matter of degree.

  In this case, the second premise in the argument from (3) treats “mental illness” as an all-or-nothing matter. The argument assumes that either one is mentally ill, or else one is not.

  Suppose, however, that mental illness admits of degrees. Suppose that one could be a little mentally ill, or more mentally ill, or extremely mentally ill. Suppose further that, depending on how often one does very strange things, one will be more or less mentally ill. If that is the case, the sentence, “there is no important difference between someone who does very strange things some of the time and someone else who does very strange things just a little bit more of the time” is false. It is false because, in fact, there is a difference between someone who does very strange things some of the time and someone who does them a bit more. That difference, furthermore, is important to being mentally ill. The difference is in the degree to which one is mentally ill, though, rather than whether one is mentally ill at all."

Now this may seem mind bending but this exercise is almost at the end of the course and a lot has gone before. But I hope this gives a little flavour, why the above argument is not sound.

There is so much instereting material in the Think again! course. There was also an example of an argument concerning evolution, which I though was very interesting and is relevant to the Restorative Exercise's perspective of evolution. I have written up my thoughts on it and am at five pages at the moment, so will have to shorten that a little before putting it on the blog.

Happy learning!

Understanding what "Katy Says" - the ankle wobble question

Understanding what "Katy Says"

This is for my RES (TM) fellows or anyone who is interested in Restorative Exercise (TM). Sometimes it is hard to be a woman and sometimes it is hard to understand what Katy Bowman is saying. 

There was recently an interesting question raised at a Restorative Exercise ™ Facebook group (not my question by the way). Restorative Exercise (TM) is a movement education course that was designed by Katy Bowman that I took last year. 

My anatomical knowledge is very basic and reading the answer given by Katy Bowman did not enlighten me when I first read through it, so I thought I shall use my recently acquired skills of taking and rearranging arguments to find out the message within. I acquired this skill from a coursera course: Think again! It's all about constructing different arguments, how to deconstruct an argument, looking at different ways to reason and how to work with probabilities etc. It's going on now if you want to join.

NUMBER ONE RULE OF ARGUMENTS: Always try and make the person, who has put an argument forward, look as good as possible. You will only learn from someone else, when you interpret their argument IN THE BEST POSSIBLE WAY. 

So here it goes. Considering rule number 1 but also making sure that the arguments brought forward are valid. 

THE QUESTION:

How does pure sagittal plane dorsi flexion during gait (as taught in RE™) fit in with the axis of inclination of the ankle (which is oblique, triplanar and through both malleoli)? 

Rephrased for non-anatomists: 

How does  pointing and flexing the foot straight forward during gait (as taught in RE (TM)) fit in with the axis of movement of the ankle - which is at an angle, through three planes and through both ankle bones)? 

If you want to know what angle the ankle hinge/axis is at, look at your ankle joint as marked by the inner and outer ankle bones and imagine a straight line between them. The inner ankle bone is forward and higher and the outer ankle bone lower and further back.

Source (6)

Source (6)

When I first read this question, I thought there was an issue with the feet pointing straight ahead. I thought, if the axis of movement is at an angle then the foot should be at the same angle i.e. slightly pointed outwards. But it turns out this is not the case. The foot is attached to the ankle in such a way that the ankle and foot always turn out together.  No, the issue talked about is: the way the ankle is attached to the foot causes the foot to wobble slightly with every step, i.e. the inner foot lifts and lowers slightly with every step and why isn’t this considered in the way walking is described in Restorative Exercise (TM)? If you want to see the wobble in the foot talked about have a look at source (2) below, which shows a computer simulation of the ankle joint.

Here is the answer by Katy Bowman (in black), my remarks and thoughts are added in colour:

I'm hoping that you all have an A-HA moment after reading this answer.  I am excited. Also, you can review the section in the Foot Book about why normal (turnout) is not necessarily natural

Reviewed info and the main points are: turn out of the foot is not natural as some studies showed, since the population being studied has been under the influence of military training and ballet, which taught them wrong alignment (heels together and feet turned out), or started to align their feet wrongly when these ideas spread to the wider population. So turn out maybe normal but not natural. Is this a valid argument? Has everyone in the study and wider population been influenced by military and ballet training? Don’t know. So will leave the argument stand as it is. 

The information you've are referencing has been presented as "how the axis of inclination of the ankle is" but should have been presented as "the axis of ankle inclination of a particular group of people." It might also be more simple to write that when evaluating non-European tali, data collected shows their hinges to be more horizontal than European ankles. The talus (plural tali) is a bone that connects the back of the foot to the two shin bones: the fibula and the tibia. You can see the bony protrusion where these bones connect to the tallus, commonly described as the inner and outer ankle bone. These bony protrusion are also called malleoli. See figures above.

Katy’s reply implies that the ankle set-up on an inclination is a characteristic of European (maybe Western?) cultures and that non-Europeans have a hinge that is more horizontal, i.e. the shin bones connect to the talus more horizontally, the malleoli are of similar height and at a similar distance to the heel. Unfortunately there is no reference to check this.

Try this: Align your foot, shank and knee pit. Alignment: the foot’s outer edge is facing straight forward and the knee pit is facing straight back. If you can’t keep the ball down, don’t worry as it’s not necessary right now. You should now have your ankle's angle of inclination and it should be fairly horizontal. I can’t get my ankle bones horizontal to each other following these instructions. My outer ankle is still lower than my inner ankle. I can get them more in-line i.e. the are a similar distance from the heel if I drop the inner foot (evert the foot) or rotate the knee towards the mid-line of the body (internally rotate the knee). But I wouldn’t be able to walk like this.

Now, without moving your foot, allow your thigh and shank to relax and rotate back where it came from. If you hold a pen (or other straight object to mimic a hinge) before and after, you will see that the resulting hinge is probably at an inclined (from horizontal in three planes) angle -- the ankle mentioned in the question. My ankle inclination stays the same more or less. This demonstration does not work for me, but it’s difficult to show something in words. 

One of the issues with creating a list of anatomical norms is, no one is using an objective reference system. The objective reference system I think here is the same for both sides of the arguments, i.e. the way the bones attach to the foot or how they should attach. Should they attach in the way they have been found to attach in mentioned studies/question or should the attachment points be more horizontal.

If researchers, measuring these axis used anatomical neutral in the thighs, shank and foot bones, they would come do a different conclusion.  This is difficult to evaluate as the researchers or the research is not defined/referenced, so no way to check if they used anatomical neutral or not. 

Instead, they are measuring how the ankle is moving relative to the ground -- not the body. So, if we measured the ankle axis on an anatomically neutral body, we would measure how the ankle is moving relative to the body. Does that make sense? Could I measure the ankle on an anatomically neutral body and measure how it moves relative to the ground? I think so. 

Ideally, the ankle hinge would be relatively horizontal relative to the ground AND the body, when on a flat surface. If a hinge is horizontal it is horizontal as measured by a water level. It does not matter if you attach a body or the ground to it. Can something be relative horizontal? No. So, the argument is that ideally the ankle joint should be as horizontal as possible.

When we look at what the body does with the purpose of trying to identify and quantify "what the body is supposed to do" one's point of reference is very important. Yes, this does however not give any reason to believe the RE (TM) point of reference is the right one.

Not only is this data collected from a shoe wearing and sitting population (weak foot and lateral hip musculature), this data is analysed by a group of people who have only known artificially flat surfaces and are trying to make sense of data with respect to this context. Again, this data is not defined, so can not validate if the researcher are a shoe wearing and sitting population. Let’s assume they are. Do weak foot and lateral hip musculature stop you from collecting valid data? I don’t see a connection there. They may analyse the data in a shoe wearing context but how likely is it that they have only known artificial surfaces? Very unlikely. Also the information I found on the web (see references below) all researchers looked at the skeleton/muscle/tendon of the foot individually and how it moved as a whole as well as movement of the barefoot and used theoretically modelling to try and work out how the ankle joint is arcticulating.

While Restorative Exercise™ does use the "hinge" model, we don't discount that the subtalar joint can adjust itself in multiple planes, though we interpret this ankle motion differently than most communities. Ok, RE (TM) uses a hinge model for the ankle joint and also believes that the foot can adjust itself in multiple planes at the joint below the ankle joint i.e. subtalar joint. But this is not relevant to the question. The questioner also uses a hinge model. The question is what does the angle of the hinge cause the foot to do, does it cause it to wobble slightly with every step or not?

The current model of human study seems to have that, when there are multiple degrees of freedom of a joint, the body must require cycling through them. Meaning, walking must require not just a front-to-back motion of the ankle, but also a right to left, diagonal, etc. I don’t think this valid. For example, just because I can circumduct my hip, does not mean, that I am required to do this whenever I walk. I don’t think any human study or current model if such exists, says I should do this when I walk. Studies and the question posed suggest that you are forced to wobble slightly because of how the joint is set up - not a choice.

The body above the ankle is "fixed" and the ground is "fixed" so the ankle "must" wobble about in order to be used as it design would implicate. Again, this is not implied in the question or any studies referenced below. The questioner is not implying you should wobble with ever step but your ankle joint causes you to wobble slightly because of the anatomical features of it being at an angle.

An alternative interpretation would be, humans need to be able to maintain the stability of their entire body despite the contour of the surface. Yes but not relevant to the question. If you're hiking and step on a small mound, your foot and ankle need to adapt to prevent the pelvis (and then spine) from lurching. Meaning that relatively speaking, the body is "fixed", the ankle is "fixed" and it's the ground that is wobbling. Yes but not relevant to the question as the question never implied you would/should not be able to do this. 

Said another way: We do not want a constant horizontal axis of the subtalar joint, we want a net sagittal-plane movement. The axis should be adjustable depending on what our foot is stepping on -- probably why the ankle is so deformable in the first place. If it were a hinge more like the knee, every pitch of the ground would require the body align to the surface. Not feasible for the human body trying to walk, at least before most of the planet's terrain was replaced with artificially flat surfaces.  Yes, but again not relevant to the question as now we are discussing the subtalar joint, which is not the joint talked about in the question. 

Because the ankle deforms kind of like a gyroscope, it is tempting to determine that the foot needs to move through all planes while walking (which is thinking like a flat-floored, shoe-wearing researcher) (this is not impied in the question, see my example of hip circumduction above) instead of concluding with a better-supported argument that the shank and everything above it should be able to move effortlessly in the sagittal plane as the ankle and foot actively deal with what the Earth's surface presents. How is this argument better supported? By what evidence, mathematical/computational modelling, anatomical studies, thought experiments? Yes we should be able to move forward (sagittal plane) effortlessly but this does not refer to the question.

CONCLUSIONS:

Right, so what have I learnt. Katy Bowman has argued that the ankle hinge being at an angle is a characteristic of a study on European populations and that non-Europeans have a more horizontal ankle joint. With a demonstration, Katy tries to show that the ankle joint can be positioned more horizontally with neutral RE (TM) alignment. This experiment did not work for me. 

I came to the conclusion, that the ankle joint is determined by the way the bones are attached to each other and can’t be changed by positioning/alignment during normal gait/walking. Katy Bowman argues that the ankle joint needs to be more horizontal. Which I agree would stop the forced wobble of the forefoot when walking. The only way I can see me getting a more horizontal ankle joint is by growing same length shin bones and repositioning the bones in the foot. Not something I can do anything about as I am not considering surgery. Maybe through evolution this can change but not in my lifetime. Would be interesting to further investigate the studies on non-European ankles and why they are more horizontal.

Otherwise, I am keeping my mind open. General info on the web indicates that the forced wobble is inevitable apart from maybe Gray's (4) description of the ankle joint. I have tried to observe this wobble myself while walking and when flexing and pointing the foot in the air. I think I can see the wobble, if I point the foot in the air but am not sure I can see it when walking. (Difficult to observe though). I think like everything this issue will be dependent on the person looked at and their anthropometric dimensions (how long are their bones and how are they positioned, etc.)

What this answer by Katy Bowman does unfortunately not discuss is why the wobble of the foot in respect to the ankle is a problem. How big is it for a European/Western foot? What are the effects we try to avoid? Is there a problem or can we set the movement aside as clinically insignificant? I am thinking that if I can’t do anything about this and it doesn't have any negative side effects, there is no need to worry any further. Seems like a lot to do about nothing.

I have learnt a lot about the ankle structure though. As an insteresting bit on the side: Did you know that the ankle is a lot more stable when the foot is flexed as the bones of the foot wedge in-between the ankle bones. So if you walk with high heels with foot pointing away from the knee, the instability in your foot is not only caused by poorer balance but also by a less stable ankle structure.

So thank you again, Katy Bowman, for inspiring thought and helping me understand the body - this time the ankle joint - better.

And a trophy for you, dear reader, if you got all the way to the end of this posting. You certainly have stamina.

References: (some results of a Goggle search on ankle joint)

(1) The ankle:

http://www.gla.ac.uk/ibls/US/fab/tutorial/anatomy/anklet.html

(2) Ankle & Subtalar Joint Motion Function Explained Biomechanic of the Foot

http://www.youtube.com/watch?v=0R4zRSE_-40

(3) Joints of the ankle and foot:

http://download.videohelp.com/vitualis/med/anklejnt.htm

(4) Henry Gray (1821 - 1865). Anatomy of the Human Body. 1918

http://www.bartleby.com/107/95.html

(5) Hall, Susan (2012) Basic Biomechanics. 6th Edition. International Edition. McGraw-Hill. New York.

(6) The ankle complex:

http://www.pt.ntu.edu.tw/hmchai/Kinesiology/KINlower/Ankle.htm

When will I be able to do the Kangaroo squat

... or what do I need to be able to do, to achieve the ultimate Restorative Exercise (TM) squat

There are different ways to squat but on the of the holy grails of The Wholebody Aligment course is a squat with vertical shins and a neutral spine, just like a Kanagroo (that's why I call it the Kangaroo squat). Saves the knees and lower back and opens the hips fully, stretches the backside etc...

As you can see the shins are lovely and vertical and the spine is in Kangaroo neutral. Now, the human spine is not curved like a Kanagroo's, so to achieve the same squat with neutral human spine, we will have to keep the neutral curves of the spine and an overall more or less straight line between pelvis and neck. So, what does the human vertical shine/neutral spine squat look like?

Vertical Shin and neutral spine - arms reaching foward to help balance

Now, I can't do this squat, so I thought I will try and find out what I will have to be able to do to achieve goal of all goals. I have two problems with this squat, firstly I can't open my hips enough to keep neutral spine and vertical shins or on the other hand, if I keep my spine neutral I can't balance and fall on my behind. So I measured the length of my body parts and drew my bits and the angles I will have to be able to achieve and compared them to "normal" range of motion of the knee and hip joints.

My body part length:

Head: 24 cm

Neck: 10 cm

Arms: 66 cm

Thigh: 42 cm

Calf: 46 cm

Foot: 20 cm

Torso: 50 cm

The percentages, show how much of my body weight is in front and how much is behind the shins to be able to balance the amount of weight in front and behind the shin needs to be the same, otherwise I'll fall backwards. See my last blog entry for further details.

Now, with 153 deg knee flexion I need to be able to achieve 195 deg hip flexion to be able to keep my spine in neutral. So my thighs are not only lined up with my torso, but the torso is forward of the thighs, to keep my balance. My question is, can I achieve 195 deg hip flexion? I found values for normal hip flexion on the web (see sources below) and the highest hip flexion observed in general population is 141 deg. And may I just say, that this is not a 30 year old desk bound person, but babies of the ages of 0 - 2 years. With maximum "normal" range of hip flexion and neutral spine, my squat looks like this:

As you will be able to see, there is no way you can keep yourself from falling backwards. So is it possible to increase the hip flexion to more? I suppose, a ballerina may be able to achieve 180 deg e.g. by bringing her extended leg to the ear and keeping the spine neutral. But to be able to do the squat with neutral spine, I will need to flex the hip even further to 195 deg. Sounds, like it will be very unlikely for me to be ever able to do this.

This example is based on my body part measurements and the hip flexion I need to achieve. If you are looking at different body types, you can see how this may influence the ability to squat. Say, you were Mister Incredible. His centre of gravity is way in his chest as he carries all his weight in the muscles around there. His legs are also very short. So he will not have to achieve the same hip flexion as me.

His hip flexion has to be less as his upper body is counter blancing the lower body and his thighs are a lot shorter. So if you are this body shape, your changes are a lot higher to be able to achieve the Kangaroo squat badge. You can see this in small toddlers. If they squat they are able to keep there shins vertical and spine in neutral, because their legs are short in comparision to the upper body and their head is huge and a great counter-balance. Over the age of 2ish this ability seems to disappear as body proportions change. 

If you are a more normal pear or apple shape and you carry your weight around the middle of your body, you'll look more like this:

And as you can see, the chances of you winning the kangaroo squat badge are very low.

So what is the best way to squat, if the holy grail is out of reach. 

1. You can bring your knees forward over your toes and keep a neutral spine. This moves the centre of gravity forward over the feet and stops you from falling over. This does however put more pressure on your knees.

2. You can stand on your mat with heels raised and toes on the floor. Again this moves the centre of gravity forward and stops you from falling over. This protects the knees a little better than option one but will put more pressure on your forefoot.

3. You can flex your spine and keep shins vertical. This will protect your knees but puts a lot of pressure on your lower back.

Now all of the above options have some downside. Choose the one that puts pressure on areas of your body that aren't shot already. I prefer to bring my knees forward as my knees are still ok but my lower back is not.

There is however one last option and I love this the best. It won't help you getting into or out of a full squat but when you are there, squat like the kanagroo and use some support under your backside. The kanagroo evolved a strong tail, but since this will take me too long, I am using a block or beanbag once I am in the squat position as a support, to keep both my shins vertical and the spine neutral.

Good luck with your squatting!!

Normal range of motion:

http://www.dshs.wa.gov/pdf/ms/forms/13_585a.pdf

Normal joint range of motion (ROM):

http://pjroxburgh.tripod.com/new_page_5.htm

What is range of motion?

http://osteoarthritis.about.com/od/osteoarthritisdiagnosis/a/range_of_motion.htm

Range of Joint Motion by Lloyd L. Laubach:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790003569_1979003569.pdf

Normal Joint Range of Motion Study:

http://www.cdc.gov/ncbddd/jointrom/