There have been many studies abroad on the effects of prolonged sitting and standing on physical health. Generally sitting for more than 2-4 hours is called sedentary. Research shows that most Chinese people sit and stand for 6-9 hours a day or more. If sitting and standing for 9.6 hours a day, the incidence of neck sprain (prolonged tension in the trapezius muscle), upper back pain, heart disease, colon cancer (for every 2 hours more sitting, the risk of colon cancer increases by 8%), low back pain, joint pain, varicose veins, osteoporosis, obesity, lumbar disc herniation, etc. will increase very much.