As a teacher, I'm surprised by how many kids don't know these easy tips. It requires staying a bit organized, but it pays off two ways: 1. Saving your back and 2. Preventing you from looking like a dork with a 50 lb. backpack!
During college I did something almost the same. I bought coated paper folders with two pockets and assigned the left side to one class and the right side to another class. I paired them according to my class schedule. Since I had purchased different color folders, I could always glance into my backpack to make sure I had the right folders for the right classes.
Get a planner and use it!
Please do not overpack your backpack!!
In college I carried all my class books in one bag to
save time. One day while I was carring my book bag, I felt exteme pain in my upper back. I had torn my neck muscles. After which, I had to take electro-therapy for 3 months. The pain was so bad I couldn't dress my self for 2 days.
It took my sister and I a couple of years to develop the same method of taking one folder with paper in them to, to all of the day's classes, and then transfering it into one binder at night. Not only that but we promised ourselves to read each classes notes a minimum of two times before putting them away. I had a little spiral bound notebook where I would write questions regarding the notes (that I couldn't find answers to in textbooks), took that to class the next day and cornered the professor at the end of class.