Everything you need to unlearn about sitting down and leaning back in your chair

Almost half our lives are spent sitting. A poor sitting posture can put more strain on your spine than lifting heavy weights. It is, therefore, important to understand the right way to sit, especially if you are required to sit for long.
Sitting for a long period can strain your neck and back, and increase the risk of intervertebral disc bulges. Our backbone, or the vertebral column, is made up of alternating bones and a soft jelly-like structure called discs. When they bulge, they can compress the spinal cord/nerve that they are supposed to protect.
The spine is like a chassis for the whole body. If the spine is not held in a good posture, there will be too much pressure on the discs.
Good posture is not about the spine being straight. The spine actually has curves—convex in the neck and low back but concave in the thoracic (upper-back) region. Too straight or too curved compromises the springiness of the spine, effectively risking too much pressure on low-back discs. Good posture would be one where the spine is held tall, maintaining the curves mentioned above, but just.
While sitting does, in fact, compress the spine, sitting in a good posture reduces the compression. For that reason, the spine needs to be lengthened at all times.
You need to reclaim your spine’s springiness and be light. When your spine is lengthened, your head will be well balanced on the top of your spine. This balancing is a dynamic act, not a forced static one. Your arms and legs move freely from a supporting back. It’s almost like trying to balance a cue on your fingertip. Initially, it’ll be a struggle and your “good posture” won’t last very long. There will be discomfort and pain too. But soon enough, it’ll become second nature to you.
Sitting straight or completely tall is not correct either, the spine needs to be held at an approximate 5-degree slant.
The spine needs to be very dynamic, not stiff at all times. If you let go of the spine, it helps hold your upper (arms) and lower limbs (legs) very comfortably. If you make the spine rigid, the arms and legs are held stiff as well. This adds to tension in the shoulders and lower back, which will then lead to neck and upper-back pain along with low-back pain.
Everyone keeps talking about good posture, but it’s not sustainable if the muscles that are supposed to hold that good posture don’t have the right balance of strength and flexibility.
There is first a need to correct that imperfection by doing exercises with the correct techniques under supervision. Easier said than done. I struggle with helping people with this one all the time because fitness trainers just don’t pay enough attention to this.
Also, we all like to blame our tools, in this case our office chairs, for our incorrect posture without knowing how to use our bodies optimally. In the popular illustration showing our evolution from being a chimpanzee to a hunter to a farmer to a man sitting in front of the computer, the one big change is that we have finally lost contact with the ground. Most of us sit on chairs that have wheels all day long. I like to call them wheel-chairs as they make sure you’ll need one soon. Many of these chairs are also sold as ergonomically designed, which is often not the case.

But the chairs alone are not to be blamed. It is how you sit on the chair that also affects your posture. Here are some tips that will train you to sit better, independently, without using the backrest at all.
  • Look for a chair with a seat which is parallel or slightly leaning forward to the ground, such that your hips are either at the same level as the knees or very slightly higher. Your hips should never be lower than the knees as that forces you to sink in the chair and does not allow you to take control of your posture even if you want to.
  • You should be sitting in the middle of the seat.
  • Now think of an equilateral triangle, with your sitting bones forming one tip of the triangle. The base of both your feet form the other two tips of the triangle. The gap between your feet should be as much as the length of your thigh.
  • The angles between your torso and thighs should be 90 degrees or slightly more.
  • The angle beneath your knee joint should be 90 degrees, so that your feet are right under your respective knee joints.
  • Sit tall like a puppet: Imagine there’s a string attached to the top of your head pulling you up. It is not really forcing you up, the imaginary string keeps you tall, but your head isn’t stiff and the shoulders are relaxed.
  • Relax your neck and shoulders while you’re thinking of growing taller all the time.
  • Imagine that the strings on your shoulders are cut so that your shoulders are not raised any more. Instead, they are relaxed and fall freely. Now just to test the freedom of your neck, move your head the way the Noddy dog in the car would, i.e., bend your skull backward and forward as if it’s on a pole. Keeping your back tall, imagine that pull of the string is at a 5-degree angle, such that you are tilting forward, without slouching, such that your centre of gravity lies between the equilateral triangle.
You’ll be surprised to find that you can keep this position for a very long time. This will make your backrest redundant. It will also help you get rid of your expensive sofas and get back to sitting on Swiss balls.
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What to avoid in a chair and why
  • A chair with wheels doesn’t let you rest your feet flat on the ground. Even if it does, your chair is not stable, hence you are not really in control.
Opt for: A chair without wheels, which is stable and sturdy. The good old benches in schools or straight-back dining chairs do a good job. The so-called ergonomic chairs make your chairs more mobile, when it is you who should be more mobile.
  • The seat on a chair should not be slanting back. This will make your hips lower than your knees and force you to slouch.
Opt for:The seat should be flat or just very slightly slanting forward. Your thighs need to be either parallel to the ground or very slightly slanting down.
  • The length of the seat you sit on should not be too long, so that the backrest is too far away: No matter how important it is for you not to use the backrest all the time, once in a while we all want to rest our backs. If the backrest is too far away, it will again make you slouch.
Opt for:The length of the seat should be such that you are able to shuffle your buttocks all the way back, so that the backrest then gives ample support to your back.
  • The angle of the backrest should not be leaning too far back. Chairs with this kind of backrest are useless as they don’t encourage you to sit tall.
Opt for:A chair with a slight lean, if at all. Good old dining chairs work very well.
  • The backrest of a chair should not be too flexible, because your back will not get enough support. It will make you lean back even when you want to sit tall.
Opt for:A chair with a backrest that is firm and does not give too much. This will give better support to your back.
  • The chair should not be too high. If it is, you will not be able to let your feet rest flat on the ground. This will reduce your chances of sitting up tall. Also, if it happens to be too low, the angle at your knee joint will be too acute, and won’t provide enough support for your lower back. This will force you to slouch your back, no matter how much you want to sit tall.
Opt for:The height of the chair should be such that your feet are flat on the ground and the angle at your knee joints is 90 degrees or slightly more. It will give you a better opportunity to sit tall.

Rajat Chauhan is an ultra marathon runner and a doctor specializing in sports and exercise medicine and musculoskeletal medicine, and founder of Back 2 Fitness. He is also associate editor, British Journal of Sports Medicine.
This piece is primarily based on the original work of F. M. Alexander (Alexander Technique), modified by Dr Wilfred Barlow, and introduced into London College of Osteopathic Medicine (LCOM) by Dr John Lester. Dr Chauhan was introduced to them in 2004 by Dr Roderic MacDonald, Principal, LCOM.