Category Archives: Sitting Posture

10 Beware the Backward Sloping Chair

backward sloping chair 2Try this experiment—this works best if you have two identical chairs. If you only have one you can work with that. The chair should have a relatively firm seat—a typical kitchen chair works well. Determine if the chair seat (a) slopes backward (the front of the seat is higher than the back), (b) is level or (c) slopes forward (the front of the seat is lower than the back). You will create two different seats so you can contrast them—one that slopes backward and one that is level or slopes forward a bit. You will need several same sized books to adjust the chair seats. If your chair is level put two same sized books under the front legs so that the seat slopes backward. If your chair slopes backward put two same sized books under the back legs so that the seat is level or slopes slightly forward.

Sit on both chairs. Sit toward the front of the chair seat and don’t lean back. This is called active or task sitting (as contrasted with restive sitting, when you lean against the back of a chair). Don’t think too much. See if your body prefers one seat over the other.

Which one would you prefer to sit on if you were going to work on your laptop at the table, eat your lunch or write a letter?

Most people find is that they prefer the chair with the seat that is flat or sloped slightly forward.

Why would this be?

Sit on your chair that has the level or slightly forward sloping seat. What are you sitting on? If you have your bottom behind you (refer to Post 9) you will be sitting on your sitting bones. Remember that these sitting bones are rounded or rocker shaped.

The fact that your sitting bones are rounded is very important. What happens when you put a round object on a backward sloping seat? It rolls backward! When the sitting bones roll backward it pulls the pelvis backward and causes the whole trunk to collapse into a c-shape, putting pressure on the lower back. It is nearly impossible at this point then to bend forward using the hip joints. Instead you are left to bend at your waist, which is not a joint at all. A recipe for disaster!

To deal with backward sloping chairs I often fold up my jacket and use it as a pillow to level out the seat as best I can. There are commercially made wedge shaped cushions to help correct backward sloping seats. If you invest in a wedge cushion I suggest a rather firm one.

Take a survey of how many chairs you see that slope backward, even slightly. You will be surprised how ubiquitous they are.

So, why do so many chairs have backward sloping seats? One reason is that they are easy to stack.

Our bodies are paying a high price for the ease of storing a bunch of chairs!

If this topic is of particular interest to you check out this podcast with Galen Cranz, author of The Chair: Rethinking Culture, Body and Design

9 Your Bottom Belongs Behind You

Let’s stay down at the bottom end of the spine and get more acquainted with the pelvis.

When you are standing you stand on your two feet. I think we can agree on that. When you are sitting upright on a chair you sit with the majority of the weight on your two sitting bones. Sitting bones is a term often used for the two rocker shaped protrusions at the bottom of the pelvis. Ischial tuberosities is the correct anatomical term but that is a mouthful. Besides that it sounds like some sort of disease. Sitting bones is easier to remember and sounds more benign.

illustration of pelvis with rocker shaped sitting bones

Fig 1: Your sitting bones are your internal rocking chair.

If you sit down on a relatively firm chair and put your hands under you, between you and the chair you should be able to feel these two rocker shaped bones. Rock and roll around on them. Rock forward and back. Make a circle going to the right. Make a circle going to the left. Get fancy and make a figure eight! I like to think of my sitting bones as my internal rocking chair.

Your pelvis serves as the foundation for your upper half. Therefore you want to make sure it is squarely under you when you are sitting. In order to have your pelvis and sitting bones squarely under you, you must get your bottom behind you. That’s important so I am going to repeat it.

In order for your pelvis and your sitting bones to be squarely under you, you must get your bottom behind you.

Don’t sit on your bottom. Sit on your sitting bones.

Young girl using laptop on beach

Fig 2: This girl is sitting on her bottom

young boy seated on a pumpkin

Fig 3: This little boy is sitting with his bottom behind him

If you sit on your sitting bones you will have much easier access to your hip joints which is where you need to bend from if you are going to move forward toward something like the computer keyboard or some project you are doing on the table in front of you, or to reach for something.

If you imagine that you had a tail, sitting with your bottom tucked under you would be like sitting on your tail. Sitting with your bottom behind you would be like placing your tail out behind you.

So go forth, explore, experiment and get to know your sitting bones. You will, by the way, find it much easier to get your sitting bones squarely under you if you are sitting on a flat seat as opposed to one that slopes backward. Why would that be? Stay tuned…

Picture Credits: Fig 1: Aron Czerveny. Available as a free download  (Thank you Tim Soar!); Fig 2: Image courtesy of photostock at FreeDigitalPhotos.net; Fig 3: Image courtesy of Clare Bloomfield at FreeDigitalPhotos.net