What Are the Basics of Ergonomic Chair Design?

Ergonomic computer chair, it is based on "ergonomics" theory, which summarizes the various data of people in the process of using computer chairs; and based on ergonomic data combined with modern chair manufacturing technology, developed for the human body A computer work chair that sits correctly and adjusts comfort.

Ergonomic computer chair

Ergonomic computer chair, it is based on "

Ergonomic computer chair is also called ergonomic chair, ergonomic office chair, it is based on the "ergonomics" theory, by statistically summarizing the various data of people in the process of using computer chairs, and based on the final statistical data Designed and developed computer chairs.

Physiological characteristics of human sitting computer chair

The most natural posture of a person is an upright standing posture, and the spine is basically S-shaped when standing upright. However, compared with the upright standing posture, the sitting posture is beneficial to the blood circulation in the lower part of the body and reduces muscle fatigue in the lower limbs. At the same time, the sitting posture is also beneficial to maintaining the body's stability.

However, when sitting, the pelvis is tilted backwards, so the sacrum at the lower back is also tilted, causing the spine to change from an S-shape (normal shape) to an arch shape. . The improper design of the sitting surface of the chair will compress the thighs, hinder the blood circulation of the lower limbs, and cause numbness of the lower limbs.

The intervertebral disc of the spine is under pressure, and the incorrect sitting position can not only reduce the load on the waist, but also increase the load. Sitting straight is helpful for reducing the pressure in the intervertebral disc, but the muscle load is increased. Sitting down is good for muscle relaxation, but it increases the internal pressure in the disc. Therefore, the inclination and shape of the backrest can affect the disc and back muscles.

Ergonomic computer chair human sitting size basis

A. Sitting height: 450-550mm office chair. Sitting height is generally based on the calf length plus the 5th percentile of foot height as the design basis. The front edge of the seat should be 30-50mm lower than the height of the knee socket of the human body, and be made into a radius of 25-50mm. The sitting surface cannot be too high or too low. H = Height of calf socket + shoe thickness (20-40mm)-proper clearance (10-20mm)

B, sitting width: generally greater than 380mm. The armchair is not less than 460mm. Resting chairs such as sofas are larger than 480mm, generally 520 ~ 560. B = body shoulder width + winter clothing thickness + activity margin

C. Sitting depth: 400 ~ 440mm in the national standard, the seat depth for sofas and other rest seats can be larger, 480 ~ 600mm. Design with the 5th percentile of the sitting depth. T = horizontal thigh length -60mm (clearance)

D. Sitting and backrest inclination: The inclination of the sitting (back) refers to the angle between the sitting (or back) and the horizontal plane. Generally, take a rest chair 19 ° ~ 20 °; 98 ° ~ 112 °. For a work chair, since the seated person needs to tilt forward, the inclination angle should not be too large. It can be 4 ° ~ 6 °; 95 ° ~ 100 °.

E. The height of the backrest. Generally in the lower edge of the scapula is appropriate. A waist pad is set at the waist, preferably 250mm. The position of the waist varies with different sides of the backrest inclination.

F. Armrest height: The height of the armrest refers to the distance from the upper edge of the armrest to the sitting surface. The main function is to support the weight of the arm and reduce the shoulder burden. The height of the armrest is generally 200 to 300mm above the effective thickness of the cushion.

G. Seat cushion: When a person is sitting, about 75% of the human body s weight is supported by the area around the ischial tuberosity of about 25c. Sitting for a long time will cause pressure fatigue, causing hip pain and numbness. If a soft and hard cushion is added to the sitting surface, the contact support area can be increased and the pressure can be dispersed.