• The optimal seat height is reached when the knees have an angle of about 90 degrees (thighs and feet horizontally, it is important that your feet should rest spread out on the floor and not on the base). Make sure you don´t feel pressure in the lower thigh (retains the bloodstream). The ideal working height will be achieved, when your arms also form an angle of about 90 ° with the virtually horizontal forearms line, on the table surface.
  • Do not cross your legs when you are sitting, since the pelvis will tilt forward and the lumbar vertebrae take the wrong position.
  • If the chair has a seat depth adjustment, adjust it so when you back is in touch with the backrest, there is approximately an inch in width, between the knees and the front edge of the chair. The hocks should never be in contact with the front edge of the seat. We always sit back completely and in full contact with the backrest.
  • The column rests optimally if the lumbar pad, located at the bottom of the back, is just above the waist, that is to say, at the point where more curved are the lumbar vertebrae. This is achieved by adjusting the height of the lumbar support according to our specific needs.
  • We will adjust the back pressure exerted by the backrest manually, adapting it to our weight, tension must be adjusted so that our body is in balance.
  • Practice a dynamic position, without blocking the backrest as many times as possible. We must get used to use the locking mechanism backrest angle, only when the user wants to stay in a reclining posture for a considerable time.
  • Avoid leaning sideways. If you have to pick up an object from the ground, do not lean sideways, turn the chair toward the object and bend over your legs to pick it up.

The bent spine has become a normal sitting position for many people, it is not surprising that they have become accustomed to this position, that in the long run, produce a hump effect, decreased muscle, tendon and ligament structure, making this wrong position a fixed posture. Any correction of this fixed position will create, at first, some problems adjusting to the correct and healthy posture.

Remember that any equipment is only as good as how to use it. If a chair is only used by one person, it must be adjusted to fit exactly the needs of the user, many people incorrectly sits in chairs adjusted incorrectly. The correct setting of an ergonomic chair, is a requisite for maintaining a healthy posture. We recommend carefully reading the instructions of your chair and optimize its adjustment.


Back pain is one of the most common problems that we can develop throughout our life, it is the cause of a large percentage of sick leaves and is a frequent cause of medical consultation, only 5% of people born with defects back, all others are acquired later. The increasingly intensive computer use, makes us spend more hours a day sitting in the working chair, so we must ensure an ergonomically suitable and physiologically healthy position. Furthermore it is shown, that our working posture affects our well-being, in a subjective and objective way, physiologically incorrect posture causes more tension in the body with consequent premature fatigue, lower performance and increased risk of accidents. To fully understand the implications of an ergonomic sitting position, we must first familiarize ourselves with our own anatomy:

The spine is made up of seven cervical vertebrae, twelve thoracic or dorsal, five lumbar vertebrae and five fused ones that form the sacrum, attached to this the coccyx or rump, consisting of three to five vestigial or rudimentary vertebrae. Between these vertebrae are the intervertebral discs, which act as water beds, making flexible the vertebrae and maintaining a constant distance between them. The intervertebral discs are like a sponge, when compressed emptied and decompressed when saturated.

We have a spine with four physiological curves which distribute in a better way the loads supported by the vertebrae. The normal curvatures of the spine are the cervical curvature, the thoracic or dorsal, lumbar and sacral. When we sat down, we tilt the pelvis backwards. By the rotation of the sacrum, lumbar spine bends back and forms a hunched back, which means an unnatural posture and a distension of the spine. Arguably, the act of sitting, requires a muscular effort. Not so much the act itself, but the activity of the supporting muscles which represents hard work.

In its normal upright position our spine can perfectly handle the pressure. However, if subjected to stress by being folded (due to a general bad posture or weakness of the supporting muscles), the structures of the movement segment (such as the annulus fibrosus of the intervertebral discs and ligaments), are subject to an excessive voltage. The consequences range from acute pain and chronic degenerative disease.

Muscle tension can only be avoided by controlling the posture and practicing regular exercise including stretching. Ultimately, this is the only effective way to restore normal functional capacity of muscles. The best way to avoid unhealthy sitting posture is to control the position and not maintain a static position for extended periods, we can say that the intervertebral disk benefits with movement.

Postura recomendada sillas ergonómicas
Regarding office chairs, the smallest characteristics of manufacture, can cause a great effect on the ergonomic and dynamic posture, let us see which aspects should be taken into account when choosing a chair:

Seat: First, the seat must be upholstered, so the buttocks do not feel the pressure points after sitting for several hours, also the contours of the seat must be rounded and upholstery must allow that the weight is distributed evenly, to avoid feeling pressure on the thighs.

The fabric should be breathable, that is to say, the material must absorb body heat and moisture to avoid the unpleasant sensation that provides its accumulation.

The length of the seat is also important and can cause problems depending on the user’s height, to prevent it, it has been developed a movable seat depth up to 4 cm and is designed to shape a small recess in the front edge to avoid roadblocks in the thighs.

However, the seat can only provide great support if the user sits correctly, in full contact with the backrest.

The backrest: When you remain in the chair for long periods of time, the demands on the back are higher, making particularly recommended a chair with adjustable lumbar support and an adjustable backrest height to adapt its position to the physical constitution of the user.