Thiết kế nơi làm việc của bạn một cách khoa học. Đừng ngồi quá lâu. Đừng cúi xuống nhìn điện thoại quá thường xuyên. Cặp sách nặng phải đeo trên hai vai. Rèn luyện thể chất đúng kĩ thuật.

I'm interested in that, but I only have a few mins. Can you give me at most the first 500 characters of a detailed explanation in English about that?
Many people suffer from a stiff neck because their work setup is not ergonomic. Position your chair so that you sit with your feet flat on the floor and your arms rest on your desk. If you have a computer monitor, make sure it is at eye level. If you sit at a desk all day or you spend a lot of time in the car, take a lot of short breaks. Moving around gives your muscles a chance to stretch out instead of remaining rigid for hours on end. Craning your neck downwards constantly can slowly harm you