About the office chair size

In front of the seat along the vertical distance to the ground is called the seat height, seat height is one of the main factors affecting the degree of sitting comfort, unreasonable seat height will affect people's sitting posture, casing fatigue on waist,  producing diseases such as lumbar disc long time down. A part of the body pressure is distributed on the legs. If the seat is too high and the legs are suspended from the ground, the thigh blood vessels will be compressed and the blood circulation will be affected; If the seat is too low, the knee joint will arch upward and the body pressure will be concentrated on the upper body. And the reasonable seat height, according to the ergonomic principle should be: seat height = calf + foot + shoe thickness - appropriate space, the interval is 43-53 cm.

The distance from the front edge to the back edge of the seat becomes the seat depth. The seat depth relates to whether the back of the human body can be attached to the back of the seat. If the seat face is too deep, the support point of the human back will be suspended, resulting in numbness of the calf, etc.; If the seat face is too shallow, the front side of the thigh will hang, and all the weight is on the calf, the body fatigue will be accelerated. According to ergonomic studies, the seat depth interval is 39.5-46cm.

When the staff is in the sitting position, the two ischial tubercles under the human pelvis tend to be horizontal. If the Angle design of the seat surface is not reasonable and presents a bucket shape, the femur will rotate upward, and the hip muscles may get pressure and the body will feel uncomfortable. The seat width is set by the size of the human hip plus the appropriate range of motion, so the seat surface design should be as wide as possible. According to different human body size, the seat width is 46-50cm.

The design of armrest can reduce the burden for the arm, so that the upper limb muscles can rest better. When the human body gets up or changes posture, it can support the body to help the body maintain balance, but the height of the armrest should be in reasonable design, the armrest which is too high or too low will cause arm fatigue. According to the ergonomic research, the height of the armrest is related to the distance to the seat surface, and the distance controlling within 19cm-25 cm can meet the needs of most staff. The Angle of the front side of the armrest should also change with the seat Angle and backrest Angle.

The main function of the lumbar lean is to support the waist, so that the waist muscles can relax, and the back of the human body can form the lower point support and the upper point support, so that the back of the human body can get a complete rest. According to human physiological data, the right height of the waist is the fourth and fifth lumbar vertebra, 15-18cm from the cushion, in line with human physiological curve to ensure the comfort of sitting posture.

Therefore, the ideal office chair should be based on the anthropometric size, in strict accordance with the ergonomic design of the seat. Even employees will not feel physically and mentally tired in a lot of long-term work, so as to reduce the diseases caused by uncomfortable sitting posture, so that the work can be completed more quickly and effectively.

Post time: May-16-2023