Is Your Child's Backpack Making Grade?
While backpacks are one of the most convenient ways to carry books and school supplies, an overloaded and/or improperly worn backpack gets a failing grade, according to the American Physical Therapy Association (APTA).
"Wearing backpacks improperly or ones that are too heavy put children at increased risk for musculoskeletal injuries," says Mary Ann Wilmarth, PT, DPT, MS, OCS, assistant dean and director of the transitional doctor of physical therapy degree at Northeastern University in Boston.
Wilmarth, an APTA member, conducted a study in 2001 at a private, pre-kindergarten-through-9th grade school in Andover, Massachusetts, and found that postural changes, particularly excessive forward head posture, are magnified when the backpack weighs more than 10 to 15 percent of the student's bodyweight. The postural imbalances appeared to be most significant with pre-pubescent female students.
Although several studies regarding chronic backpack injuries have been conducted in the United States, Italy, Australia and New Zealand since Wilmarth's study, the results appear to be similar, she said. Further research is necessary, though, to more accurately determine the longer-term effects of improper loading.
According to Wilmarth, injury can occur when a child, in trying to adapt to a heavy load, uses faulty postures such as arching the back, bending forward, twisting, or leaning to one side. These postural adaptations can cause improper spinal alignment, which hampers functioning of the disks that provide shock absorption. A backpack load that is too heavy also causes muscles and soft tissues to work harder, leading to strain and fatigue. This leaves the neck, shoulders, and back more vulnerable to injury.
Another study conducted by Wilmarth, this one in 2003, found that college-aged students also were affected by disproportionate weight and improper use of backpacks, although not as significantly as with the younger students.
Wilmarth recommends following these tips for safe backpack use:
-- Wear both straps. Using only one strap causes one side of the body to bear the majority of the weight of the backpack. By wearing two shoulder straps, the weight of the backpack is better distributed, and a well-aligned symmetrical posture is promoted.
-- Put on and remove backpacks carefully. Keep the trunk of your body stable and avoid excessive twisting.
-- 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 child's center of gravity. Shoulder straps should be adjusted to allow the child to put on and take off the backpack without difficulty and permit free movement of the arms. Straps should not be too loose, and the backpack should not extend below the low back.
-- Lighten the load. Keep the load at 10 to 15 percent 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.
-- Encourage activity. Children who are active tend to have better muscle flexibility and strength, which makes it easier to carry a backpack.
When selecting a new backpack, Wilmarth recommends choosing ergonomically designed features that enhance safety and comfort:
-- A padded back to reduce pressure on the back, shoulders, and underarm regions, and enhance comfort;
-- Wide, padded shoulder straps instead of narrow straps, which can hinder circulation, causing numbness or tingling in the arms and, over time, may cause weakness in the hands;
-- Hip and chest belts to transfer some of the backpack weight from the back and shoulders to the hips and torso;
-- Multiple compartments to better distribute the weight in the backpack, keep items secure, and ease access to the contents; and
-- Reflective material to enhance visibility of the child to drivers at night.
Wilmarth found that backpacks with wheels were a good option for younger students who did not change classes or need to go up and down stairs frequently. However, there are precautions to take with "rolling backpacks" as well. Be sure that the extended handle is long enough so that the child is not forced to twist and bend, and that the wheels are sufficiently large so that the backpack doesn't shake or topple. Older students found traditional backpacks to be better due to the frequent walking between classes and also when going to and from school.
Some students have two sets of books so they don't have to carry heavy textbooks to and from school. In addition, an alternative to conventional backpacks may be considered, such as one that allows the wearer to carry the load evenly on both sides of the body, rather than solely on the back.
Parents and children can avoid injury by recognizing the following warning signs that the backpack is too heavy:
-- Change in posture when wearing the backpack;
-- Struggling when putting on or taking off the backpack;
-- Pain when wearing the backpack;
-- Tingling or numbness in arms and legs, mostly arms; or
-- Red marks on the shoulders.