Your Back Hates Your Backpack

Photo: Edward Berthelot/Getty Images

With some students returning to schools where lockers aren’t available due to Covid-19 prevention efforts, parents would be wise to make sure their children have the right backpack and that it’s packed properly and not overloaded, lest the load reshape a young spine and cause unnecessary pain.

In fact, potential posture problems and pain caused by inadequate packs and poor packing practices extend to anyone of any age who routinely carries a load, whether it’s in a briefcase, messenger bag, gym bag — perhaps a Covid-inspired backpack for rediscovering nature — or even a small purse. Especially if a person is mostly sedentary.

But “load carriage,” as researchers call it, doesn’t have to be such a headache if a person has the right bag for the job, understands how carrying it in various ways can affect their body mechanics, and takes a few simple precautions.

Degeneration in kids’ backs like never before

“I’ve been in practice for 30 years now,” says Scott Bautch, president of the Council on Occupational Health at the American Chiropractic Association (ACA), who I spoke to prior to the pandemic. “Degeneration that I never saw in children’s backs, I’m seeing in children’s backs now.” Technology and lack of physical activity have created “horrible posture” in people young and old, he says. “I have very young people with old backs.”

There has been “very little research” into back pain among children, says Peter Fabricant, MD, an orthopedic surgeon at the Hospital of Special Surgery in New York whose recent study addresses that shortcoming. About 15% of 10-year-olds say they’ve had back pain in the past year, and with each year of age the figure rises, to about 45% of 18-year-olds, according to the research published earlier this year in the journal Spine.

Among all ages 10 to 18, 8.9% report severe back pain in the past year. The study does not show whether the problem has grown over time, and it did not investigate causes, but the researchers did determine this: “Compared to participants that did not use a bag, participants using a backpack with one strap, a backpack with two straps, a tote bag or a rolling bag had greater odds of experiencing back pain.”

Adults at risk, too

Whether you pack a few extra external pounds for your job, for school, for a serious hike, or just for daily necessities, four things beyond your own fitness determine whether your body can handle it:

  • The weight you carry
  • Where it’s distributed in the bag
  • Where and how it’s carried on your body
  • How often and how long you pack it around

According to the ACA, children should not carry more than 5% to 10% of their body weight in a backpack. But even just a couple pounds in a purse or briefcase can force abnormal body mechanics that, over time, result in sore backs, shoulders, arms, necks or knees, and even chronic headaches, says Robin Orr, PhD, a professor of physiotherapy and director of the Tactical Research Unit at Bond University in Australia.

“Lighter loads, carried every day and poorly distributed on the body, can likewise lead to long-term problems,” Orr says by email. “Even a small one-to-two-kg of load [two to four pounds] can make a big difference over days, months, and years.”

People often don’t realize their pain stems from improper load carriage, Orr says, because the symptoms come on gradually. He gives the example of carrying something really heavy — say, a bag of cement — in front of you. The weight moves your center of gravity forward, so you lean back to keep your balance. Your shoulder and back muscles are strained. You feel all this immediately. The effects of lighter loads are more subtle but still potentially damaging, Orr explains.

“For example, a briefcase always carried in the right hand can lead to a myriad of postural adjustments,” he says. You might also swing your free arm differently so it doesn’t hit your body. “These changes have implications up and down the body, from positioning of the head (due to a pull of shoulder muscles on one side of the body and the need to adjust the tilt of the head to keep the eyes level to offset any compensatory lean) to uneven loading of structures in the feet,” Orr explains.

“Lighter loads, carried every day and poorly distributed on the body, can likewise lead to long-term problems.”

The core of the problem

The spine is particularly vulnerable to load-carriage damage, says Bautch, the ACA chiropractor, and a lack of core muscle strength is a key reason he’s seeing more back pain in young people. Core muscles protect the skeletal structure as we move.

“When I lean to the right or lean to the left, my body has to fire in a certain order,” Bautch explains. “If there’s a weakness along that chain, then something else has to work really hard.”

That can eventually cause modest, chronic pain in various muscles, tendons, and joints — pain whose source is hard to identify. Or it can become serious.

“If I bend forward, my muscles, if they’re not strong, then all that pressure goes down on my disks,” Bautch says. “The disk slowly works its way backward. The fibers that hold it in place stretch and you get a bulging disk.” Continue that pressure and the disk can rupture.

Meantime, the body’s soft tissue in many kids and adults — especially ligaments, tendons, and disks — aren’t getting the lubrication they need, which comes from movement. “Being sedentary just breaks the body down,” Bautch says. Add to that the constant downward gaze related to phone use, the perpetual forward lean caused by heavy, ill-fitted backpacks, and it’s no wonder young people’s spines are being reshaped.

“For many years now, I have not seen a normal neck on an X-ray of somebody under 18 who doesn’t have their head carriage forward,” Bautch says. “Kids’ spines when they’re growing are soft. If we have them in abnormal postures for long periods of time their vertebrae will actually change to that.”

Packing advice for kids and adults

Among the ways to prevent injury when carrying things is to pick a tote that’s the right size, then lighten the load as much as possible.

“Backpacks and purses are like garages,” Bautch says. “If I have two stalls, I can only get one car in. If I have three stalls, I can only get one car in,” because like many people, he fills the rest of the space with things he doesn’t really need.

Roller bags have become a popular alternative for students, but their purpose is defeated if a kid has to climb stairs. Some schools ban them because they clog hallways and risk trips and falls. A 2019 study found roller bags should not carry more than 20% of a child’s body weight, given the gait changes and twisting they force.

Bautch’s advice for backpacks, beyond the vital need to use both shoulder straps:

  • Fit the pack to the individual and buy new ones as kids grow. Adjust straps so the top of the backpack is level with the first big bone you feel below the back of the neck. The bottom of the bag should be at the belt line. If it’s too low, the child will lean forward.
  • There should be two compartments (front-to-back) so heavier items can be packed close to the body.
  • Padding should be sufficient so hard objects don’t dig into the back. “If it’s not comfortable, they’ll lean forward, trying to take pressure off the bony part of the shoulder,” he says.
  • A top loop is vital. A child should pick the backpack up and place it on a chair or table before putting it on. “The most dangerous thing is to take it from the floor and swing it on your back so you have a twisting motion at the same time you’re lifting,” Bautch says.

The same principles apply to adult backpacks. For very heavy packs, as when hiking, the heaviest objects should be close to the body and lower in the pack, to lower the center of gravity and help prevent falls.

Orr cautions against assuming a certain amount of weight, or a set percentage of body weight, will be safe. Risks vary based on an individual’s strength and fitness, duration of the carrying, terrain, and other circumstances. For a kid carrying a backpack uphill, the steepness of the hill will have a greater impact on their body than the load weight alone, he says.

Other tips: If you carry a briefcase or strap a bag on one shoulder, switch sides frequently, Orr says. And his most important advice: Empty your bag often and remove anything that isn’t vital.

As important as all these prevention tips are, perhaps the most important tactic would be to get in shape. A 2017 study of adults with round shoulders and head too far forward found that specific stretching exercises can improve the postural issues. (Exercise does not have to be particularly difficult, experts say, and can range from just walking to some simple doctor-designed workouts anyone can do to whole-body exercises you can do at home with no equipment.)

Bautch encourages everyone to simply get off the couch and move more.

“Living rooms became resting rooms a hundred years ago when we physically were tired,” Bautch says. “But we’re not now. We’re mentally tired. So we need to think of our living room as being a motion room and earn our computer time or earn our TV time with motion and not just rest our bodies.”

Independent health and science journalist, former editor-in-chief of LiveScience, writing about how we age and how to optimize your mind and body through time.