Weight of backpack for Japanese students regulations

Today a friend of mine complained that the bag of her son is too heavy. Checking it out on the internet I found out that according to the "American Physical Therapy Associan, American Academy of Orthopedic Surgeons, and the American Chiropractic Association" a backpack should not weight more than the 5 pounds for a child that weights 60 pounds.

Her son is 60 pounds (27.2 kilo) and his backpack is just over 15 pound (7 kilo).

This is of course Japan, so the regulations are different, but it does make me wonder if there are any regulations regarding this in Japan. Is it healthy for a boy of 27 kilo, 7 years old to carry a bag that is 7 kilo...

When I was 7 all I took with me to school were my peanut butter sandwiches and my reading book.

Sometimes I think the empty bag must outweigh first-graders. In case of an artillery attack I can think of nothing more sturdy to take shelter behind.

Just called the board of education to ask them if their are any regulations or guidelines regarding this, but according to them their aren't any in the city of Amagasaki.

Thing you can do is talk to the school, and the homeroom teacher regarding when and when not to leave the books at home/school.

Still I think it is strange, that kids need to carry a bag that heavy... or is it just me.

How about everyone else, do you remember if you had a heavy bag when you went to elementary school?

Have you ever watched the kids coming home on the last day of school? They look like pack mules.

I didn't go to elementary school in Japan. Different countries, different customs. My kid has a heavy backpack, but the only regulation as far as I know is whether he can actually lift it.