Heavy backpacks pose a risk to students' spines if worn incorrectly.
It's back to school time and that means kids are stuffing their backpacks with books and supplies, but doctors say those weighted-down bags could cause lasting health problems for children.
Dr. Ramin Raiszadeh is an orthopedic surgeon.
He says kids should only be carrying 10 to 15 percent of their body weight in their backpacks.
The consequences of carrying too much weight can be painful.
"The backpack can not only just cause the back pain, it can cause shoulder pain. It can cause mid-back pain," says Dr. Raiszadeh.
Other concerns include muscle spasms, sway back, leg pain, and in the most serious cases disc degeneration.
Backpacks can also exacerbate underlying problems that need to be treated.
Dr. Raiszadeh says pain can usually be treated by reducing the weight and wearing backpacks correctly.
Straps should be worn on both shoulders to spread the weight evenly.
They should be padded, two inches wide and fit snugly.
The backpack shouldn't hang down past the child's lower back.
The doctor says the best option is pulling books in a backpack with wheels.