The best sitting position has been discussed long and hard. Different seat settings and chair types have been advocated. But a good sitting position is a combination of balancing, relieving and relaxing postures and a sitting position that allows for natural, activity-related movements.
Common to most theories of how people should sit is the aspiration to give the upper body/back the same profile as when standing. We have come a bit along the way if we can have this balanced body profile irrespective of whether we are sitting in a forward or backward leaning position.
Through evolution, our body movements have been adapted to suit a physically active life, which means it is important that the body is given the chance to move. The longer we have to sit, the more important it is that we move regularly. Twenty minutes is usually the magical time limit for when things start happening in the body if we are sitting in the wrong position. We need to listen to these signals otherwise the problems could lay the foundation for other, more complicated musculoskeletal disorders, which take many years to notice.
It is therefore vital to choose a comfortable work chair that provides very good relief and mobility, and that as far as possible reduces tensions and thereby load-related movements. If this can also be combined with the variation of sitting and standing, and that you can move in a way that is different, then this is an excellent attribute.
Malmstolen is an ergonomically designed work chair that provides optimal support, relief and relaxation in the majority of sitting positions. It is extremely responsive allowing you to easily change position.
The best relief you get is when you are sitting in a slightly reclined position. The upper body is then relieved as the weight of your body is supported by the chair. Furthermore, the angle of your hip opens by more than 90 degrees which allows better blood circulation. The chair follows the body and provides the platform to move naturally.
Malmstolen has prioritised the importance of movement. When rocking backwards on a work chair with knee-tilt (Model 4000 and Model R4) or a synchronous knee-tilt (Model 7000, Model Cpod and model R7), the seat height drops slightly. However, your hands will be directly above the axis of motion of the knee-tilt mechanism and move only slightly vertically. Your arms and shoulders will be relaxed even when you work more forward leaning or when you lean backwards. From an overall ergonomic point of view therefore, the knee-tilt mechanism or synchronous knee-tilt is preferable to the so-called central tilt mechanism. The exception here is a saddle seat such as Malmstolen High5 which has a centred tilt. As your legs hang along the sides of the saddle, they are not affected in the same way as when sitting on a traditional flat seat.
Here you sit as if you were sitting on horseback. The upper body posture resembles a standing position. This is good. This is a position that works well when you are working facing a desk. But unless the chair is made to be flexible and responsive and provide opportunities for other sitting positions, the rider position will be static.
There is after all a major and crucial difference between sitting on a horse's back and an office chair. The rider follows the horse's motion which provides a natural movement variation. The chair does not move by itself. There is a major risk of entering a constant stress cycle if the chair does not allow for a variety of positions.
Most work chairs have the option of leaning the seat or the whole chair forwards. The reason is to reduce the pressure against the underside of the thighs; known as the hamstring muscle. Pressure here shortens the muscle, which gets the whole pelvis to fall backwards with an arch to the back as a consequence.
The disadvantage is that many people have the sensation of sliding off their seat. There is also the risk of increased swelling in the lower legs and feet. If you rest your knees against the knee support you create a static position resulting in a static load.
This is a semi-standing position with the same objective as the rider position - to give your upper body the same balance you have when standing. You often sit in a work chair where the seat resembles a horse or bike saddle. The chair may also have a smaller backrest. These types of chairs are frequently used at standing desks.
To achieve the same position as when standing requires that the feet are placed under the seat so that the centre of gravity's vertical line passes through the spine in the same way as when standing. The thigh bones are now steeply inclined and the lower legs are slanted backwards allowing your feet to be in the correct position. A seat that pushes against the underside of your thighs results in the pelvis tilting backwards and your back will arch as soon as you relax.
If you move your feet forwards in front of the vertical line, the centre of gravity moves, and a muscular tension will be required to hold your upper body upright. If you move your feet further back instead, your upper body will tend to fall forwards. As a way of avoiding this, you "overarch" which will create discomfort .
In order to be able to sit and balance in this way, the seat with its pressure must not impede the body from assuming the correct posture. The surface of the seat that is to absorb the vertically directed forces of the body's weight must therefore be very small. When you sit in the above-mentioned position with your body in perfect balance, a large force from the weight of the body in other words will be distributed over a very small area. The weight distribution of the seat will therefore be substantially reduced. This pressure inhibits blood circulation in the area around the lower abdomen.
As with the riding position, the risk is that the posture becomes static.
This way of sitting is based on the theory that the body is "looking to move" and is adapted to a life in motion. There is a saying that "the next position is the best one." The argument is also put forward that the body never adopts any specific sitting position, but that we spontaneously and naturally are constantly looking for a variation of sitting positions. By way of example "free-float" chairs where the seat and backrest move independently of each other in order to follow the movements of the body are often designed based on this philosophy.
Movement helps blood circulation and is a prerequisite for the exchange of nutrients to work in the spinal disks. In addition, movement stimulates many other body functions.
This philosophy often has no proper analysis of the actual cause of the specific movements. Are the movements load or activity related? The consequence is often that the chair follows the load related movements of the body, i.e. the body's symptoms for loads that both the chair and the surrounding work tools might cause, instead of offering the body the actual support and relief it is normally looking for. Loads generate a lot of really spontaneous movements, if not in an unconscious form then sooner or later in a conscious form; they operate here therefore as a defence system for the body. The risk is that the movements, due to a level of tension in the muscular system that is too great, do not have the intended positive effect, as tense muscles impede blood circulation.
This has been the most commonly recommended seating position for decades. Hip joint and knee joint at a 90 degree angle. The position is easy to learn, but presupposes that the chair has a backrest with an ample lumbar support, otherwise you will sink down.
With a 90 degree angle particularly in the hip joints, the muscle and ligament extension is increased in the lumbar region. Even when you have a substantial backrest, the risk for fatigue increases in this region, including sometimes higher up beyond the back. The consequence of this is often that you slide forwards on your seat and in so doing open up your hip angle. The backrest does not then give you the same support any more. If you relax you will sink down.
Backward leaning sitting position
This position can provide exceptional relief for your body, which can be attributed to basic physics, when you place the weight of your body against the chair. But it is important that the chair seat and backrest are able to offer an optimal conformal contact area against our bodies. Only then can you achieve optimum relief without the upper body losing its naturally balanced profile.
There should be an effectively relieving neckrest when the act of leaning backwards starts to have a major effect on the throat muscle system as it tries to keep your head balanced. The supporting parts of the chair must not be rigid but offer a certain amount of resilience which means that movements are flexible when it comes to relief. Make sure the hips are able to benefit from an angle that is more open than 90 degrees.
A backward leaning sitting position is often applicable when working at a terminal if you position the computer screen, keyboard and mouse/control device in a way that ensures an agreeable visual and working distance. It is usually quite easy to get this sitting position to work well.