Students are headed back to school in person, and for many, that means a return to wearing backpacks full of books, homework and other school supplies.
Backpacks give students independence and the ability to carry what they need for the day, in addition to being a way to express their personal style.
But when backpacks aren't used properly, they can lead to long-term issues with pain, posture and other musculoskeletal problems.
"Backpacks should be treated like clothes and replaced when they have too much wear to function or hold weight evenly, or when they no longer meet the fit requirements," said Leah Van Antwerp, an occupational therapist and clinical assistant professor in the School of Health and Human Sciences at IUPUI.
Van Antwerp said that when wearing a backpack, it's important to pay attention to three main factors to keep your body healthy.
Find the right fit
The specific type of backpack matters less than how it fits and how your wear it.
Van Antwerp said the top of a good-sized backpack should rest about 2 inches below the shoulder blades, and the bottom of the backpack should fall at or slightly above the waistline. The straps should also be well-padded and adjusted so the backpack is carried close to the body, as wearing it too far away can contribute to poor posture.
It's also important to wear both shoulder straps every time, as the uneven weight distribution can lead to muscle strain or imbalance, she said.
Lighten your load
A well-fitting backpack won't do you any good if you're carrying too much weight, Van Antwerp said.
According to the American Occupational Therapy Association, backpacks should be used to carry no more than 10% of your body weight. That means a 50-pound child shouldn't carry more than 5 pounds, a 100-pound child shouldn't carry more than 10 pounds, and so on.
The weight carried in a backpack should also be evenly distributed, with the heaviest items placed at the bottom/center of the back, and without one side weighing more than the other. Extra backpack features such as hip belts and padded backs can help significantly relieve pain or redistribute the weight, she said.
If your school supplies weigh more than what's recommended, or if you can't find a way to evenly distribute the weight, Van Antwerp suggests using a rolling backpack with wheels or a cart.
Using online textbooks and other digital resources can also help reduce the number of books and paper you need to carry around.
"Just make sure you are also taking care of your shoulders and eyes when using more screens by doing regular 'tech neck' stretches and eye exercises," she said.
Know the warning signs
If a child is complaining or displaying signs of pain -- especially in their shoulders or upper and lower back -- those can be immediate signs that backpacks are too heavy or not fitting properly, Van Antwerp said.
"An ill-fitting or too-heavy backpack could also cause pain in the hips or knees, if the child is compensating by walking differently to accommodate the extra weight," she said.
Other short-term indicators of backpack issues include red marks on the skin or indentations from shoulder straps that last longer than 20 minutes or are painful to touch, as well as any skin rashes/irritation from rubbing that lasts longer than 20 minutes.
Longer-term symptoms of backpack issues include stooping posture or rounded shoulders, muscle strain or imbalance, and musculoskeletal problems or pain, she said.