A Better Way to Sit Up Straight in a Chair

We all have been told to sit up straight, don't slump, and maintain good posture.  Have you ever taken a close look at such advice? No doubt, if properly understood, it is a good thing. Chronic slumping is not conducive to concentration,  personal growth, maturity or success - that is for sure.  But have you considered that there are many ways to "not slump" and of all the many choices, stiffening the back, pulling the shoulders back and lifting the chest is probably the least desirable?

Probably before about 1950, when  there was less stress, pollution, no computers or video games and less TV, and people got more exercise and movement naturally (people did not drive so much, walked more, etc)  - "sitting up straight" would have naturally been more functional (people would have naturally, dynamically organized their pelvis, legs, chair, abdomen and breathing  to facilitate elegantly balanced upright posture) and it would have made sense to give others, and yourself, that instruction as a helpful reminder. 

Remember, it was in the early 1950's that the cold war intensified, and we had all these stiff chested generals on TV or newspaper images, telling us to build fall-out shelters, and how much we should be afraid of Russia and nuclear war.  Before then, also, kids were outside playing, not sitting motionless watching TV. They had better movement, they did not have a frozen pelvis like most of us today do. Most of us have a pelvis that can do nothing more than be sat upon for many hours, with the tailbone tucked under as well, and hold stiff while walking! I see that everywhere. Most people today cannot initiate movement from their pelvis (due to long sitting, with an immobile pelvis and a deadened tailbone, while moving the torso, eyes, head and neck and arms). If I ask a new client to do such a thing, I will get a blank stare. So deep is the hypnosis! A person without a functional pelvis is a person without any real personal power; he can never be fully involved in any activity, even if he tries, since a large part of his nervous system (related to the pelvis and balancing etc) is shut down. So many brilliant intellectuals sadly fall into that category. 

Normal human movement means at a minimum that the pelvis knows about and is responsive to what is going on in the rest of the body. Now, the funny thing about this is you can't see the lack of  this in others unless you yourself have a functional pelvis. Until then, everybody else looks like they are just doing the normal thing - what's wrong with it? But when you yourself - perhaps after taking a Feldenkrais Training or martial arts training for some years - have a pelvis that has a larger vocabulary than just be sat upon, hold stiff while walking, and sex - you'll see that what most people do "normally" is grotesque. 

In addition, before the 1950's most folks did not have staring eyes - from TV and computers, as is the case today. Compare magazine pictures of people from the 1940's or before to those of today! Especially compare the eyes of young children. Today, we all have dead eyes, by comparison. TV, video games and computers have done that to us. It has come upon us so gradually that few of us understand what has happened. Staring eyes creates head forward posture, stilted breathing, and fixity in every muscle in the body - that is not how you want to be. Yet, today, it is considered normal. 

One more item:  Since the 1950's the mania for tight abs, suck up the gut, has evolved into cherished cultural dogma  - and few indeed are those who have the courage to challenge it. Perhaps this is related to our increased exposure to all types of media - no longer just magazines, newspapers and radio; we now have in addition TV, movies, live action billboards, video games, computers etc.  On all these media, there are advertisements, where the young women or men are sucking up their gut while they pose for the photo or video clip.  Before 1950 or so, and throughout all of ancient history - if you study the pictures, photographs and artwork, you'll see that people had bigger bellies. They were much more relaxed in their core. They could breathe. Today, stress has multiplied so much that it is rare to see anybody like  that. What a paradox and a pity! That our culture worships flat bellies, the very thing that will create even more stress, anger, high blood pressure, anorexia and burn-out. It was not like this, not so much, before 1950.   

Sitting up straight, "good posture" now means to most people stiffen the back, suck up the gut, pull the shoulders back, lift the chest, stay that way at any cost, as long as possible. What is your interpretation of such advice? How have you taught your children?

It has become internalized, and we now tell ourselves to do this many times a day. It is a form of insanity, yet we can't help it. It's part of who we are. It is nearly impossible to stop doing this, cold turkey. Other people, teachers, parents, our boss, demand this of us every day. We have practiced this dozens of times a day for many years. We demand it of ourselves. Yet, stiffening like that is clear body language for panic, anger, stress, fear, submission and dogmatic, tunnel vision thinking. While this scenario has been facilitated by TV, video games and computers, and chair sitting as opposed to floor sitting,  primarily it is due to our own lack of understanding about what we are doing. 

What can be done? Somatic intervention, ATM classes or private work is not feasible for everyone. At least start to sit more on the floor. Use pillows to make yourself as comfortable as you can. Start with 10 minutes a day, say while using your laptop. Increase slowly. Shift positions often.  While sitting cross-legged (or any other way) on the floor, the pelvis learns to do a variety of things, and erect posture is nearly guaranteed to be more relaxed in the upper back and chest. Because you are closer to the floor, falling is not such an issue, the body is more relaxed, there is better blood circulation to the brain, there is less body tension or stress going on to stay balanced upright. I'd be curious to see cross-cultural studies concerning whether cultures built around floor sitting are different (and how) compared to predominantly chair-sitting cultures. For sure, there are less hip problems and hip surgeries, and less need for chiropractic, when there are less chairs. Perhaps we need to rethink our idea that floor sitting is uncivilized. 

With a little mentoring, a little understanding of what is going on, it is possible to quickly learn a much better way to sit up straight in a chair, and to have better posture at other times as well.  But some of your cherished ideas about posture will be challenged. It means being open-minded, patient and adventurous. I do hope you take the time to  read all of this long post, consider it carefully, and maybe try out some of the ideas.   

It is crucial to learn chair sitting scientifically - to do it elegantly, effortlessly. You'll amaze your friends. It is the ideal way to sit in meditation posture, or to sit at a computer. If you have children, please teach them like this, instead of just telling them sit up straight. These ideas work; they have been tested on thousands of people. It is called The Feldenkrais Method.  Try them out - Please!  I know these ideas work - when I feel my own back muscles as I sit, they are as soft as butter. Most people are shocked by that, and so I have to let them feel  for themselves. To have a relaxed back while sitting runs contrary to everything they think they have been taught to do, and be. Yes, I am sitting fully erect. I have yet to see a new client who can do that. It comes naturally to me, and soon it can be that way for you, too. 

This is a deceptively long list, because actually each item comes naturally - it's built into our ancestral nature  - with just a little encouragement. It's not like it's hard work to learn all these things. It's what a young, healthy person would do who was very conscious, body-smart, supple and adaptable, who had never before sat in a chair.  You won't have to think about all this once you know what to do. It will be second nature. It quickly becomes just one easy thing to do, not many things. 

Yes, this list is artificial. Much better would be to do Feldenkrais Awareness Through Movement (ATM) classes, where each week, you would fully embody some helpful somatic idea. You'd have a whole week to assimilate it, play with it. It is not possible to fully assimilate, or even fully understand, somatic ideas just from reading printed lists and playing a few minutes with the movements. A long list like this can give you a headache, it seems overwhelming. But here all I can do is write it down, I have no choice. At least, reading this list will give you an idea of how much work there is to  do, and you'll begin understanding why chair sitting causes back pain for so many people. Using this list is 100 times better than to continue to sit up stiffly, for hours without end!

By the way, if you're thinking you are OK because you have a fabulous, expensive and form fitting orthopedic-designed swivel office chair (or any kind of office chair - no matter how clever or unusual - besides a hard, flat wooden bench or stool with a flat backrest or no backrest), think again. Paradoxically, such expensive chairs encourage a form of body-stupidity and lack of competency, so that our internal self-care and self-adjustment mechanisms get rusty. That sets us up for injury and pain. When we do have to turn our head quickly (God forbid that we, and not the chair, should actually have to do any real movement), or get up out of the chair, or lift a heavy object while sitting, can we be easily, quickly organized (body-wise) for that activity? I think not.  In time, that chair will betray you and your old troubles, and new troubles will emerge. You'll be very puzzled since you don't want to blame a chair - it cost so much money - and came so well-recommended - but your pain will be very real. What happens?

Again, we are not built for immobility. Just imagine a wild - or even a domestic - cat or dog or bird who was required to sit in a form fitting little chair, or bucket-seated-rounded-back plastic abomination type garden chair. You'd have a very hard time to make that happen. You'd have to drug the animal. You'd have to train the animal for years to have a dead-to-movement pelvis. You'd really warp the animal's personality. They be like half zombie-dead with staring eyes.  So why do we do that to ourselves? For animals, the very idea sounds insane, so why not for us humans? It is actually insane, too, for us humans: such an office chair. The swivel feature means you cannot plant your feet, get grounded, or you go spinning. It means you never need to turn your head or swivel you eyes. It means you get way too frontally oriented, since you rarely need to organize your body, or your awareness to deal with what it to the side of you (to say nothing of what is behind you!) - all you do is swivel the chair! All the joints get lazy, and immobile. Immobile  joints soon become compressed with unconscious muscular holding all around the joints. It's like the body says: "You want immobility? OK I'll help you by tensing all the muscles around every joint".   This greatly magnifies joint pain of any kind. What an abomination (somatically speaking)!

Because we  humans have a higher-level cortical brain control of lower brain functions, that animals don't have, we are able to suppress (but not entirely eliminate) our awareness of all the many body-signals that would (initially, before we got habituated) warn us about long-continuation of doing that crazy thing: sitting in a form fitting swivel office chair. We thought it was a good thing, so we "trained ourselves" to get used to it. After all, everybody else is doing it, it feels so cool at first, so it must be good, right? Wrong. Just look at the statistics for work-related back pain! It's at epidemic levels. 

Granted, if you are very body smart, say doing martial arts or dance or yoga for hours every day, or at a very high level of athletic excellency,  you could no doubt endure (but not thrive) in such a chair for long periods of time. But you'll do much better with a hard, flat wooded bench or stool. My recommendation is that you buy such a chair, as soon as you can, and start using it for 20 minutes a day. Gradually increase. Use an inch or two of cushioning if you want to - like a folded blanket. That is fine.  It will be uncomfortable at first. Over months and years it will become your favorite chair. I have clients for whom that has become true, and they have no pain or trouble from sitting. Start using your piano bench for your home office chair! 

Form-fitting comfort of any kind, long continued, dampens movement. Granted, it sure feels good at first, maybe for half an hour, as a sort of an indulgent excursion. That is why soft sofas and expensive form-fitting office chairs sell so well. People think that comfortable, easy feeling will continue forever. It never does. I myself enjoy soft sofas and swivel chairs. But I know 20 minutes, half and hour max, and I will want to end it. My body and my brain tell me, and I listen.  It minimizes activity in the brain that is part of being human: balancing in gravity, being competent to move the body appropriately, awareness of what is happening and of objects in close proximity. Whatever a person sitting in such a chair writes, or composes, or organizes, will not be of the highest quality, compared to what he or she would produce if their nervous system were not so deformed by the chair they were sitting upon, and their habit of pelvic fixity. 

Our tendency to stiffen, the cultural dogma about tight bellies, and our staring, fixity-prone eyes have created a long list of disabilities that interfere with functional, relaxed, easy erect sitting posture.  So, it has to be a long list, for now, since each item is like an antidote to some wrong habit or faulty way of thinking about chair sitting. Play with each item for a few days; each one should give you a sense of great relief, as if your body is telling you "thank  you, finally you are doing something sensible while sitting in a chair, please do more of this." In a few weeks (if you seriously pursue this line of thinking and sitting) you will have amazingly effortless, erect and powerful looking - yet relaxed, chair sitting posture. This list is the magical formula giving how to sit erect in chair sitting posture without tensing the spine, without stiffening the chest, without fixity - yet with maximum relaxation, and minimal effort and easy balance.

Somewhere in this list, also, is the one special item that you need more than any other - I cannot predict what that may be - and that item will take away most of your back or neck pain, or shoulder pain, or  "computer stress" or "office stress and fatigue". It is worth some time to search for that. 

Consider this list as an antidote to the advice sit up straight. That simplistic advice has done more harm to individuals and society than you can possibly imagine- please read my prior posts, for more on that.  Again, the only reason this list is dauntingly long - is because our list of wrong habits and wrong ideas about movement, posture and sitting is equally long.  And remember, each item is to be understood in a dynamic context, it does not mean to be frozen motionless like that - it means to gently explore something new in a relaxed and playful manner. You should be able to move, breathe, turn the head, look around, reach - restfully - while using these ideas. From now on, when you hear that internal voice saying sit up straight, do  one or more of the following  (no more than that or you may get overwhelmed):

• Feel the contact of your sitting bones on the chair.  Deliberately do not stiffen your chest as everyone else does. Deliberately slump, staying that way. Stiffening is what people do in moments of panic and fear. You don't want to communicate that! Better to slump for a moment while you figure out a better way to come erect. If you can't feel your sitting bones, your chair is too soft, or too rounded in (like a bucket seat). Do something there to sit straighter (i.e. roll forward on sitting bones).
• Than, lean far forward, almost putting your head between your knees; as you do that walk your sitting bones as far behind you as you can do, comfortably (even doing it to a point of a little minor discomfort would be good). By walking your sitting bones behind you, you are creating a solid foundation for erect, effortless posture. It creates a lumbar curve, and prevents tucking the tailbone under (body language for cowardice and slumped posture). 
• Remember, do not stiffen or lift the chest, first let the pelvis do its proper job. Otherwise your pelvis will never learn to get involved. Eventually, your pelvis should be dynamically, continually adjusting it's tilt (in any direction) to respond to what your upper body is doing. That takes the right kind of chair, sensitivity, training and long mentoring in the  Feldenkrais Method. You can't learn that by reading a list.  But for now, it will be very good to just more or less get the pelvis tilted at the right angle to support erect sitting posture with a good lumbar curve (instead of tucking the tail, the tailbone and pelvis under, as most folks do chronically).  
• Be sure your chair is stable, the right height, and has a relatively flat, firm surface, with not too much cushioning - otherwise these ideas won't work very well (if at all).  
  
• Spread your knees apart, sense the space behind you, beneath you, and above you - in addition to the space in front of you. Imagine that you could instantly look up, look down, slump, turn, get up, roll on the floor,  each with many different variation, in any possible direction. Sit over your center, able to move in any direction. Center your breathing. Imagine you are a marital artist, and you are ready to fight or defend yourself, in any direction. Posture automatically becomes ideal when you even  think in this way, even for ten seconds.
• Once or twice a day, squeeze your eyelids tightly shut (as tightly as you can, comfortably without straining) while looking with your imagination into the far distance. Then open your eyes and look around the room - roll your rounded eyeballs in their sockets. This will reverse the tendency for the eyeballs to remain elongated from prolonged near focus vision work. Elongated eyeballs almost force you to stare, they do not rotate in the socket normally. Haven't you noticed that people look "bug eyed" if they sit at a computer for too many days in a row?  Just a little of this exercise will also release a lot of tension and stress. That's because radiant (direct) light (ie computer, TV, video games, cell phone display) are not natural in our evolutionary history (our ancestors did not look at the sun, or the moon or a fire at night, they'd lose their night vision). When we force ourselves to sit all day gazing at radiant light (computers) there is inevitably some mild low-brain shock or trauma happening (any animal would know that staring at the sun would mean going blind, and death would soon follow). That means you'll tend to squint, no matter how much you try not to squint. There are some very ancient structures in your brain that will override any conscious attempts not to squint, as soon as you stop making a deliberate effort.  Squinting puts pressure on an already elongated eyeball (eyeballs naturally elongate with near vision, and become more round with distant vision), and this mechanical pressure communicates a sense of frustrated stress to the whole body. The eyes control the body in a very real sense.  Personally, I don't think most people can sit comfortably in a chair, at a computer, unless this issue is handled. Of course, a monitor glare filter also will help. 
• Simply sense the bottom of your feet on the floor (sitting now and then without shoes is good). Simply notice if your feet are relaxed, or are they gripping the floor, holding tension. Chronic tension in the feet is where belly tension, lifted shoulders, ungrounded feelings originate. 
• Sit without shoes and use a magic marker to massage your feet - roll your feet over the marker. Or use a glass coke bottle as a foot roller, or use a couple tennis balls in a sock (to keep them from rolling away). Pressure and stimulation to the bottom of the feet (something lacking while wearing shoes on flat surfaces) encourages relaxation, grounded sensations, and whole-body relaxation.   
  
• Imagine you are being attacked with by a person with a stick, and you must defend yourself using your forearm. The attack comes from any direction, and you must twist, turn, look up, down etc to defend yourself, using both arms and legs. Playing a game like this with kids will give them an ability to acquire the best posture of anyone in their school, within a month or two at most. Hint - involve your pelvis. 
• Roll your pelvis to create the proper lumbar curve (ideally you'd want to support your pelvis just like that with a folded blanket, a foam wedge, or by sitting on the edge of the chair).
  
• Again, walk your sitting bones behind you to insure that your lumbar arch won't collapse. This is so crucial, it is worth repeating. 
  
• Relax your abdomen and belly enough so that you are not straightening your lower back, destroying your lumbar curve. Without a lumbar curve, there is no support for the upper torso, and this greatly encourages stiffening the chest or pulling shoulders back. 
  
• Fully relax your muscles, and imagine that they are hanging on your skeleton like clothes on a hanger. 
  
• Keep both feet squarely under the knees. If the feet are too far in front, it will push you into the back of the chair. If they are too far behind, they will encourage slumping forward. For a few moments feel that your feet are supporting the carriage of your head. 
  
• Keep your knees a good distance -at least hip's width - apart. Any closer and you'll automatically be propelled (however slightly) into a slump. It's because of the geometry of the hip joints: If the knees touch you want to slump, if they are far apart, you sit erect. It is easy to demonstrate this on yourself - just try it out.  Knees touching makes it easier to slump, and harder to sit up erect.  
  
• Maintain stable, erect posture using a properly positioned or dynamically responsive pelvis and relaxed torso. (The pelvic muscles are very strong and have endurance - unlike the back muscles!). This takes time, mentoring, and movement classes to fully embody. 
  
• Imagine you are breathing in from the back of the throat, or at a point between the ears, or from the back of the skull. Breathing should migrate more towards the back and sides, rounding out the sensation - instead of just being frontal.  In frontal breathing the belly expands out and in with every breath. Abdominal breathing must be more dimensional than that. If  your awareness - vision and breathing - is mostly preoccupied with only what is in front of you (like sitting at a computer) your head will tend to go forward, and other postural distortions will occur (depending on how you hold yourself).  
  
• Feel that you are resting on, or supported by, your skeleton. This means, among other things, being able to easily sense the skull resting upon the top of the spine (at least be able to imagine it). This is located (for those interested in physical or spiritual anatomy) where the medulla/spiritual eye is located - exactly halfway between the ears, not lower! It means withdrawing the attention from the front of the face, the front of the eyeballs, the mouth and nose. Surprisingly, this shift in focus produces a slight - but highly beneficial - mechanical adjustment of the carriage of the head, less protruded forward and more over the spine. 
  
• Allow your chin to stay level in a relaxed way (by relaxing the back of the neck, not by tensing the front of the neck as most folks do).
  
• Avoid protruding the head forward (imagine a feather brushing against the chin. This inhibits the universal tendency to jut the head forward - which is what we are accustomed to do while reading or using a computer). 
  
• Avoid using force to retract your head back over your torso. That is damaging and pain-inducing, and there are better ways to go about that - a future post will cover that topic). It is more than enough to just inhibit the tendency for the head to jut forward. Imagine a feather brushing  up against your chin. Be content with that.
• The best quick fix (if you must have one) for head forward posture: momentarily (not habitually) push your shoulders gently straight down (without even a trace of pulling them backwards. Pulling shoulders backwards creates head forward posture see my prior post on that topic). You should feel a gentle stretch between your shoulders and your neck. Continue to do that as you relax your back as much as possible (still sitting up erect) while at the same time lifting your upper chest- expand and lift the upper sternum. This creates grounded shoulders and retracts the head nicely. This quickly creates body-language for personal power, responsibility, competency. Chronically lifted shoulders (most folks have allowed their shoulders to drift into that configuration, through lack of proper training and understanding) is body language for "I give up", as in shrugging the shoulders. In order to do serious weight lifting, or be good at martial arts, you must learn this posture - especially grounded shoulders. Visit any gym or martial arts studio, and you'll see this.
• Lean forward and hang your arms and head between your knees. It's an extreme form of slumping. Let all the tension in your back drain away, as you progressively settle into this posture -- stay like that for at least 30 seconds, preferably up to five minutes. Relax  your neck, let your head hang fully down. Back and neck muscles never relaxed unless they are encouraged and allowed to lengthen - here they are lengthened!  And gravity does all the work. Most folks think stretching backwards is a back stretch - no, that is a belly stretch, the back muscles are tightening. When you can stay slumped down in your chair like this, you are refreshing and relaxing your back muscles so later they can do an even better job of holding your erect. Many people never relax their back muscles, ever, even for a lifetime. This is one of the best ways to do that. When you come up, do it very slowly, and use as much arm strength as possible (instead of using the back muscles to come up). That way, when you are sitting erect again, your back will be much more relaxed, and you'll begin to get a sense of how it feels to sit with a more relaxed back and softer chest.   
  
• Avoid over-tensing the belly (which causes slumping). A little belly tension is OK, though, as long as it does not freeze the reciprocal (agonist-antagonist) relationship between the lower back and the belly. To be sure that kind of fixity is not happening, for a few seconds arch or protrude your lumbar spine and belly far forward (as if you had a pot belly) and while you push it forward roll  the pelvis forward, and as you suck up the gut tightening the belly again, roll the pelvis back into a slump, and as you push your slightly distended belly to the right, your pelvis rolls diagonally to the right. You can even make circles, using the belly as the motivator/initiator, and the sitting bones and pelvis describing the circle. Toddlers have big bellies and they all know how to use their belly to help their balance, and movement. It is only when they start to "grow up" and get adult instructions about sitting up straight, concentrate, pull in the belly etc, do they lose that.  All this takes a lot of words to describe, but only a few seconds to do it. If it means taking a belly-dancing class to learn how to do this, go for it. That's better than sitting for years with a frozen belly, and frozen lumbar spine - thinking you are being very good, sucking up your gut like that. 
• The next time you see an olympic gymnast with a flat belly, instead of thinking you need to suck up your gut to be more like that, think "they have worked 6 hours a day for years to be like that. What beautiful coordination between their belly and low back! It is not just a stupidly held, sucked-up gut. There is tremendous suppleness, intelligence and strength there. They are eating a controlled diet, they burn off all of what they eat, they have good coaching. If I really aspire to such a flat belly, I'd be well-advised to do all of those things, instead  of foolishly thinking "do more sit-ups, suck up my gut all the time, try out a new diet."
  
• Remember, a belly that is holding too much tension will  encourage slumped posture. When muscles in the front of the body tighten, it causes us to slump, unless we tighten back muscles to counteract that - and that means co-contraction of flexors and extensors, resulting in tremendous compression of the spinal vertebrae. Unthinking, excess belly tension freezes the lumbar spine and pelvis motionless, it grossly distorts normal breathing, it continually creates self-dialogue, images and feelings related to panic, fear, withdrawal, anger and even rage,  it demands that we do more inefficient and stress-inducing chest breathing,  it creates co-contraction of the lumbar and belly muscles which puts the lumbar vertebrae in a vise-like compression (ever heard of compressed discs?), it reduces blood flow to the lower extremities (because those arteries pass  through the diaphragm, which is being continually drawn up with tension), it reduces circulation to the entire pelvis area, it is body language for fear or panic, it means you are being uptight and ungrounded, it means you are also drawing up the floor of your pelvis. When you unconsciously maintain tension for years in the floor of your pelvis, you are creating trouble with the lower intestines, with the sexual function, and with the bladder function.  So it is really crucial that the belly hold just enough but no more tension than you need to stabilize your erect posture. A tiny bit of tension, or neurological activation, in the belly is a very good thing; it wakes us up, it is congruent with mental alertness, it means we can be responsive to life from our core. That neurological intelligence in their core is really what we admire in the olympic gymnasts.
• Simple tell yourself many times a day "soft belly."
• If your belly is too protruded, and you still cannot imagine relaxing most of your suck-up-the-gut tension, then begin at least to explore, during  the day, some moments of relaxing the belly. Notice how much easier you can turn your head. Think more in terms of total body fitness (find a trainer) rather than over-focusing on strengthening your "abs". And consider that food allergies and parasites are a prime suspect for distended bellies.
• If you still cannot more fully relax your belly, then stop reading all the popular magazines where flat bellies are worshipped, where every magazine has an article about how to get "flat abs" in 3 minutes a day or less. Instead, look at ancient art, particularly the statuary, where you'll see even that the attractive maidens had bellies like a 4 month pregnant woman. Consider portrayals of the Buddha - is that a pot belly, or a breath belly? You'll quickly discover that the mania for flat abs, with a sucked up gut, is only a "modern-age" aberration in the long sweep of human history. Are you sure we are right, and everybody else was wrong for all those thousands of years? Personally, I vote for ancient cultures. 
• If you still cannot relax your belly, you'll need to take drastic action: stop doing video games, and trash your TV, stop going to movies, and minimize your non-essential computer time. Try not to look at billboards.  Flat belly mania is strongly communicated in all these media. And remember, that image you admire - with the flat belly - the person is probably sucking it up, after a long exhale. Plus, before they started acting in that movie, or posing for that ad, they went on a diet or fast, hired a personal trainer, and did colonics (Mae West started that trend) - just to have a flat belly! It is not natural to them, any more than it is to you. How can you breathe if you hold your belly flat, and your chest is stiffly held as well? How? 
• If that does not work either, you'll need private body-work or therapy or both. Possibly you need to release trauma, or there are abuse issues. I like Somatic Experiencing (SE)  as a therapy adjunct, since it works with the body and sensations.  
• Imagine that your tailbone is sinking to the floor (for this you need a hard flat-surfaced chair, with minimal cushioning. Otherwise your tailbone is compressed. A foam wedge with a hole for the tailbone can also be used (Tush-Cush is the brand I prefer). 
  
• Let gravity create - moment by moment - just exactly the appropriate lumbar curve to effortlessly support erect posture in the upper torso. This can happen automatically, but it takes a freed-up tailbone that hangs down without touching the chair or being pressed upon by foam or other cushioning, and some months or years of Feldenkrais mentoring. It depends on how dead your pelvis has become (relative to the job of dynamically supporting an erect torso in gravity) and how willing you are to change. 
  
• Imagine growing taller - but without effort - from the top of the head.
  
• Relax the hands - imagine quiet hands. Tension in the hands means tension in the shoulders, and slightly lifted shoulders. This will distort the posture, interfere with breathing, compress the neck and more. Quiet, restful hands are so important. 
  
• Practice reaching forward to use a mouse or keyboard with relaxed hands, wrists and fingers. Once your hand arrives at the destination, then use just enough tension to do what is needed. This is how accomplished martial artists throw a punch. Most folks are reaching with tense hands,  that means frozen shoulders, tense neck, restricted breathing and compressed joints in the fingers and wrists (conducive to carpal tunnel or arthritic pains). 

Soon, even one of these items will remind you to embody all the others. They all come as a package, and your body knows all about it very well. Trust that instinct. The only reason you have forgotten is you have stiffened all these years to sit up, instead of these things.

Recently I saw a heathy, normal 19 year-old young man with chronic back pain. We played this game, where he sat in a hard, flat surfaced chair (no backrest) while I pretended to attack him  with a foam roller, as if it were a sword. His job was to use his forearm(s), hands or legs, to defend and block my strikes. He was quick and flexible and did pretty well, considering. But, the whole time, his pelvis remained motionless.  I could not induce him, non-verbally, to initiate movement from the pelvis. I pointed this out to him, and mentioned this comes from years of sucking up the gut, and sitting in chairs, especially at school, or at video game consoles or at a computer, studying or "paying attention".  We have (most of us) learned that "paying attention" or "concentration" or "doing my best" means stiffening the spine, freezing the pelvis, tensing  the belly, restricting the breathing, tensing the fingers (to grip a pen), with a frozen facial expression. Most folks have a chronic case of this. Those rare examples who don't have this syndrome, we admire as outstanding athletes, or as people who appear to "make no effort at all, but look at how much they accomplish! It is amazing." 

Going through the above list might help, but for many of you, it will take more than that to rehabilitate a frozen pelvis and chronic sucked-up-gut, bringing them back to normal everyday function. We'd all have functional pelvis movement if, from birth, we never sat in chairs, looked at TV or computers or video games, and our teachers never asked us to sit up straight, or if we never bought into the culturally-induced idea of sucking up the gut all the time - now and then to do this is beneficial, it is good for circulation, it massages the internal organs, it releases tension. But not all the  time! Additionally, we'd need to never have acquired any ideas that sex or elimination is somehow so unclean or prohibited that therefore I must not sense or move my pelvis - many people have done exactly that (this is a somatic statement, and  no implications are intended regarding lifestyle, or what is appropriate sexual behavior), and finally, we had had appropriate athletic/movement classes while growing up - that would mean a school system where not just the talented athletes had good coaching!  For me, it took a four year Feldenkrais Training Program. And I am certainly not alone - talk  to anyone who has been through such a program, and they will all say about the same thing on this topic. 

Once you have been though such a program, or have completed some years of weekly one-hour Awareness Through Movement (ATM) classes, you won't need this list. All of that will come naturally to you. It will be stiffening the back, tensing the belly and freezing  the pelvis that will seem very strange, artificial and personal-power-diminishing. You'd look at this list and think "what a waste; I do all that automatically, without thinking".