Ergonomics play an extremely important role in the design of sihoo m90 series chairs. If you have a full-time office job, you spend eight hours a day at work. You sit at your desk and must constantly deliver peak performance. An m90 series ergonomic chair that is tailored to your needs not only improves comfort, but also increases productivity. It turns out that poor posture can lead to back problems. More than 80 percent of people over the age of 50 with sedentary jobs suffer from back pain. But ergonomic chair don't just help you reduce stress on your back, they help protect your joints as well.