Healthy Work Research: Three Must-Checks When Buying an Ergonomic Chair

"You can get injured just sitting in an office?" That was hard for our parents' generation to understand, yet today lumbar muscle strain is very common among young people. In recent years, Yihang has conducted in-depth research in the field of healthy office work. Building on its ergonomic chairs, the Yihang–Nanjing Forestry University Healthy Office Research Center has carried out a series of studies. We found that both consumers and brands focus their research on the backrest support points of office chairs while overlooking how the seat cushion affects sitting posture. How can you tell whether an office chair's cushion is truly ergonomic? Here are the key points to look for when choosing an ergonomic office chair:

I. Choose the right seat size to say goodbye to backaches and numb legs

Research shows that even when the spine is upright and the body is supported front and back to share the load, prolonged sitting can still cause fatigue if the seat height and depth are poorly dimensioned. So even a "premium" ergonomic chair can cause discomfort when used improperly.

A comfortable seat height should let the backrest support the lumbar spine and maintain its natural curve, while leaving a gap between the backs of the knees and the front edge of the seat so blood can flow freely through the legs.

The research conclusion: comfortable seat height = popliteal height + shoe heel height - an appropriate allowance (heel height is generally 25-35 mm, with an allowance of 10-20 mm)

II. Look at the cushion shape for even pressure relief

According to ergonomic principles, the most comfortable body pressure distribution spreads most of the body's weight over a larger supporting area and lower unit pressure, distributed sensibly between the cushion and the backrest.

Using seat surface pressure distribution testing, the Yihang–Nanjing Forestry University Healthy Office Research Center found that a highly comfortable seat has no high-pressure hot spots, changes in pressure are gradual and even, and adjacent pressure zones connect smoothly.

As the illustration shows, a comfortable seat should conform well to the hips and thighs, keeping the ischial tuberosities as the main support points while spreading pressure evenly across the buttocks and legs, so muscles do not feel tight even after sitting for a long time and pressure relief works far better.

III. Choose the inner and outer materials carefully for lasting comfort and breathability

A truly good office chair must have an elastic layer of suitable thickness inside the cushion. Because the outer cover is in long-term contact with the body, it should be breathable, wear-resistant and dirt-resistant, and should not generate static electricity against the body or clothing. A cushion that does not breathe creates an environment where bacteria and germs thrive, increasing the risk of urinary tract infections.

Our research found that, compared with traditional cushions, Wintex high-strength mesh fabric is more supportive and better fitting. Used as a backrest material, it follows the curve of the third and fourth lumbar vertebrae and gives the lower back elastic support; used as a cushion material, it keeps the seat breathable and strong under load, so sitting feels comfortable, cool, and never stuffy.

In designing office chairs, Yihang's design team has always been committed to "helping users sit more comfortably and healthily", using ergonomic full-body support and a rich range of adjustments to release pressure on the head, neck, and lower back, so that everyone can have a healthy chair that suits them.

Yihang–Nanjing Forestry University Healthy Office Research Center

The Yihang–Nanjing Forestry University Healthy Office Research Center was jointly established by Yihang Technology Co., Ltd. and Nanjing Forestry University. It conducts research into the ergonomic characteristics of furniture products, office behaviors, and office environments, along with related health topics, in line with the positioning of office furniture, with the aim of building a safe, healthy, comfortable, and efficient healthy-office system.