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Is Your Backpack Making the Grade?

While a backpack is still one of the best ways to tote homework, an overloaded or improperly worn backpack gets a failing grade, according to the American Physical Therapy Association (APTA).

Improper backpack use can cause injury, especially to children with young, growing muscles and joints. Injury can occur when a child is, trying to adapt to a heavy load, uses harmful postures such as arching the back, leaning forward or, if only one strap is used, leaning to one side. According to physical therapists, these postural adaptations can cause spinal compression and/or improper alignment, and may hamper the proper functioning of the disks between the vertebrae that provide shock absorption.

Worn correctly and not overloaded, a backpack is supported by some of the strongest muscles in the body: the back and abdominal muscles. These muscle groups work together to stabilize the trunk and hold the body in proper postural alignment.

Physical therapists recommend the following tips for safe backpack use:

Wrong Correct Wrong Correct
Strap on only one shoulder. Standing only on one leg, bad posture.  Wide, padded straps on both shoulders. Standing evenly on both feet, good posture.  Load too heavy. Bending too far forward.  Load no more than 10-15% of body weight. Able to stand with good posture. 

  • Wear both straps. 

Use of one strap causes one side of the body to bear the weight of the backpack causing excess strain on that side. By wearing two shoulder straps, the weight of the backpack is more evenly distributed, and the body can balance the weight with much less strain.  

  • Wear the backpack over the strongest mid-back muscles.  

Pay close attention to the way the backpack is positioned on the back. It should rest evenly in the middle of the back, near the shoulder blades. Shoulder straps should be adjusted to allow the child to put on/take off the backpack without difficulty and allow free movement of the arms. Straps should not be too loose. The backpack should not extend below the low back. 

  • Lighten the load. 

Keep the load at 10-15% or less of the child’s bodyweight. Carry only those items that are required for the day. Organize the contents of the backpack by placing the heaviest items closest to the back.  

A too-heavy load also causes muscles and soft tissues of the back to work harder, leading to strain and fatigue. This leaves the back more vulnerable to injury. A heavy load may also cause stress or compression to the shoulders and arms. When nerves are compressed, the child may experience tingling or numbness in the arms.

Here are some guidelines recommended by the American Physical Therapy Association (APTA):  

Body Weight Maximum Backpack Weight
50 pounds  5 to 7½ pounds  
55 pounds 5½ to 8¼ pounds
60 pounds 6 to 9 pounds
65 pounds 6½ to 9¾ pounds 
70 pounds 7 to 10½ pounds
75 pounds 7½ to 11¼ pounds 
80 pounds 8 to 12 pounds 
85 pounds 8½ pounds to 12¾ pounds 
90 pounds 9 pounds to 13½ pounds 
95 pounds 9½ pounds to 14¼ pounds 
100 pounds 10 to 15 pounds 
125 pounds 18 pounds 
150 pounds 20 pounds 
200+ pounds 25 pounds 

*No one should carry more than 25 pounds in a backpack*


Consult a physical therapist if your child complains of neck, shoulder, hip or back pain that you think might be related to an ill-fitting backpack.  

Some children have physical limitations that might require special adaptations. A physical therapist can help determine the best fit to help avoid further injury or pain.

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