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Back to School: Discussing the Biomechanical Impact of Backpacks

Back to School: Discussing the Biomechanical Impact of Backpacks
Sara Loesche, MS, OTR/L, CHT
January 7, 2022

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Editor's note: This text-based course is a transcript of the webinar, Back to School: Discussing the Biomechanical Impact of Backpacks, by Sara Loesche, MS, OTR/L, CHT, CEAS.

Learning Outcomes

  • After this course, participants will be able to identify outcomes of current literature related to backpack use focusing on school-age children.
  • After this course, participants will be able to recognize the risk factors and make recommendations on choosing, packing, and wearing a backpack to reduce biomechanical strain and promote student wellness.
  • After this course, participants will be able to list ideas for setting up a backpack awareness event in the community.

Introduction

Thanks for the introduction. I am thrilled to be back presenting on OccupationalTherapy.com. I have three boys: kindergartener, fourth grader, and seventh-grader. I know all about getting school supplies to and from school. I love talking about ergonomics not just in the scope of work and industry but also in the area of everyday life. This led me to think about backpack biomechanics and safely teach our kids about health and wellness habits early.

Safety and wellness can start with something as simple as a backpack. I looked into the literature of what is out there and what is being done today in research. I want to talk about what we can implement with our kids, pediatric clients, and even ourselves. 

The Backpack

There are many different kinds of bags: backpack, shoulder bag, rolling bag, and messenger bag. A bag is a necessary item for the role of being a student. One of the early safety measures for COVID was that children kept and carried all of their things with them all day in their book bags. That was certainly my experience with my children. They had their books, their iPad, coats, et cetera with them throughout the day.

As we are moving toward regular classroom routines, I hope that kids can use their lockers again and not have to keep everything with them all day. It is essential to stress healthy habits, and one way we can do that is by looking at proper backpack use.

Overview of Performance: Student

Let's look at students within the occupational therapy framework using the Occupational Therapy Practice Framework (OTPF, 4th Ed.).

  • Area of Occupation:
    • Education – "Activities needed for learning and participating in the educational environment" (p. 46)
  • Context:
    • Environmental Factors
  • Performance Patterns:
    • Habits, Routines & Roles
  • Performance Skills:
    • Motor Skills such as 'aligns', 'lifts', 'transports', etc.
  • Client Factors
    • Body Structures & Functions

AOTA, 2020

The first area is looking at occupation and education and the student role. 

The next area is context and environmental factors. Our students are either physically at school or virtually learning from home. They may need to walk, get a ride, or take the bus. Socially, they interact with other students.

The school day is based on a rhythm of habits and routines, making up performance patterns. The role of the student has its own set of behaviors that students need to adhere to throughout the day. It is crucial to build healthy habits into that routine, like wearing and packing their backpack. These are healthy habits that we can help them engage in early.

In terms of performance skills, performance skills are goal-directed skills that support performance in certain occupations. The student's body and backpack should be in alignment. We also need to look at lifting and transporting.

The last thing is the client factors, including body structures and functions. We need to look at the student's musculoskeletal, cardiovascular, and respiratory systems. Additionally, we can look at movement-related functions, mental functions, and sensory functions.

Occupation of Health Management

  • Activities related to developing, managing, and maintaining health and wellness routines, including self-management to improve or maintain health to support participation in other occupations.
    • Symptom and condition management​
  • Choosing a backpack and wearing it correctly can help children develop responsibility for their health and wellness and become aware of making healthy choices with a positive impact. 

AOTA, 2020

Health management was the newest area of occupation added into the OTPF last year. Health management is activities related to developing, managing, and maintaining health and wellness routines, including self-management. The goal of improving or maintaining health is to support participation in occupations, and part of this is symptom and condition management. It encompasses things like medication management and personal device care.

While this applies to the adult population, we can also apply health management to the younger people. Choosing a backpack and wearing it correctly can help children develop responsibility for their health and wellness and make healthy choices that can positively impact them. 

Backpack Awareness

  • American Occupational Therapy Association public health initiative started in 2000
    • "Pack It Light, Wear It Right"
    • School children carry books and other school-related items in their backpacks each day.
    • Heavy, awkward, or carried for long periods/distances
    • Can impact physical health – musculoskeletal issues, cause discomfort, impact endurance and feelings of tiredness
    • Created resources and held events, including an annual Backpack Awareness Day

(Jayaratne, Jacobs & Fernando, 2012)

Backpack awareness became an initiative back in 2000 when the American Occupational Therapy Association started this as a public health initiative. The logo was "Pack It Light, Wear It Right." Over the last two decades, since this initiative started, the backpack loads have increased for students. Medical professionals, parents, students, therapy practitioners, and educators are becoming concerned about how children use backpacks and the detrimental impacts of these increased loads.

The American Occupational Therapy Association started building this initiative each year with a Backpack Awareness Day. They created a lot of resources, held events, et cetera. They looked at what students were carrying in their backpacks each day and what kind of backpacks they were wearing. They found that students were asked to carry backpacks for extended periods for farther distances. This can impact the child's physical health, causing musculoskeletal issues, discomfort, and endurance. As this was not just happening in the US, it became a global initiative.

In 2005, Iceland took a lot of the AOTA's work and modified it culturally to work with that population. A study in Sri Lanka studied over 1600 students in middle school, grades six through eight. They looked at various backpacks and shoulder bags, even suitcase-type bags, and what they were carrying in those bags. Seventy-two percent of the students perceived that they were experiencing discomfort from carrying their school bag. The students reported pain and fatigue due to the heaviness of the backpacks. They started a backpack awareness and education program as well.

This is still a global initiative Karen Jacobs recently took over with Boston University's Promoting Occupational Therapy initiative.

International School Backpack Awareness Day 

  • October 27, 2021
  • Led by Karen Jacobs, Ed.D., OT, OTR, CPE, FAOTA, and Boston University's Promoting Occupational Therapy initiative
  • Connects with World Occupational Therapy Day and OT Global Day of Service

The AOTA still provides resources, but the annual Backpack Awareness Day has turned into an International School Backpack Awareness Day. It connects with the World Occupational Therapy Day Global Day of Service. I will talk about this a little bit more later on.

Health Consequences

As I said, there can be some health consequences to carrying a backpack (Figure 1).

Figure 1

Figure 1. Health consequences to carrying a backpack (Shaikh & Tendulkar, 2020; Mououdi, Akbari, & Mousavinasab, 2018).

There can be direct and indirect consequences. Maououdi and colleagues' (2018) study looked at adults who experienced low back pain. They reported first experiencing low back pain during their adolescent and young adult years. The choices during younger years can have health impacts down the road.

Another study by Sonna looked at backpacks that were being carried for an extended period and were greater than 10% of the individual's weight. The impact was deviated posture, musculoskeletal complaints, reports of physical fatigue, and difficulty concentrating in school.

Another report by the Newport Orthopedic Institute said that almost 40% of children (ages 11 to 14) complain of pain in their neck and lower back, and 80% say that it is because of their book bag. One more study noted that 40% of students between nine and 18 years old said they had low back pain and that low back pain was responsible for missing school days and sleep issues. Thus, the health consequences from backpack use impact other areas of occupation outside of education.

The top health consequence is musculoskeletal disorders, and that makes sense. It could be cumulative trauma or overuse as students put on and take off their backpacks multiple times throughout the day in addition to moving around with that backpack on. This includes sitting, standing, going up and downstairs, and sometimes running to catch that bus when they are late. There is a repetitive loading of the lumbar spine over time, increasing the risk for low back pain. It is easy to think that carrying your backpack on your spine will cause spinal deviation. Children are still physically developing in their bone and physical structures, so they might be more susceptible to spinal deviations as their vertebral ossification is not complete. Thus, overuse injuries might be more prominent in children than adults.

A backpack can cause changes in gait patterns and balance causing a forward trunk lean and/or pelvis deviation, and we will talk about this briefly. Carrying up to 10% or more of your body weight will increase your energy consumption. Lastly, changing the center of mass posteriorly will make the child anteriorly lean with a forward head. This reduces lung capacity and volume, affecting cardiovascular parameters like heart rate and blood pressure.

Backpack Palsy

  • Brachial plexus injury resulting from carrying heavy backpack load - Rare but well-founded
  • 33 yo male in the military (Sharp et al.)
    • Loss of sensation and loss of motor function of R UE
    • Tx: Steroids and therapy. Return to activity in 10 mo
  • 15 yo female participated in school events (Rose et al.)
    • Weakness in L UE (shoulder ABD, elevation, elbow extension, wrist/finger extension)

(Rose, Davies, Pitt, Ratnasinghe & D'Argenzio, 2016; Sharp, Wong & Stephens, 2017)

In terms of documented actual conditions, there are, although rare, instances of something called a backpack palsy, which is a brachial plexus injury from carrying a heavy backpack and the straps going through the axilla area. Backpack palsy was first found in the literature in 1969 and was connected to the military during Vietnam. It is believed that the straps of the backpacks of the rucksacks caused conduction difficulty that resulted in both motor and sensory loss. It was called cadet palsy, rucksack palsy, or backpack palsy. There have also been cases identified in the civilian population, typically associated with leisure activities like hiking.

Sharp et al. (2017) looked at the case of a 33-year-old male in the military who carried a heavy backpack for 10 hours straight. It included his rifle, body armor, and helmet. He started to notice numbness and tingling in his right upper extremity and could not move it. He went to the emergency room with paralysis and paresthesia, but he had no complaints of pain or changes in muscle bulk. He did have a complete loss of his sensory dermatomes of C6 through T1 and a one out of five manual muscle test. He barely had any movement in C5 through T1. He also had absent reflexes, although his left upper extremity was completely normal. The treatment was steroids and therapy. After about ten months, he was back to his everyday activities but not yet back to military duty.

The other study of backpack palsy was with a 15-year-old female participating in a school challenge where she walked eight to 10 hours a day for two days straight with her classmates. Her backpack was not officially weighed but was said to be about 22 pounds. She weighed about 80 pounds, had a slim frame, and had a low BMI. After the first day, she noticed numbness and tingling throughout her left hand. By the second day, she had left upper extremity weakness, and in particular, she could not extend against gravity for shoulder abduction or movement at the elbow, wrist, or fingers. Since she had no pain or change in muscle bulk, she let it go for a few days before she went to urgent care and received a diagnosis of peripheral motor neuropathy of the posterior lateral cords (of the brachial plexus) at the C5-C7 level. This injury makes sense as the axilla area is where a backpack compresses. She had conservative therapy, started to recover motor function at about four months, and fully recovered by six months. This scenario is rare but had excellent outcomes. 

In the military example, weight was an issue as it was a hefty backpack. One would think that if you have good physical strength, you should be able to carry heavier loads. Perhaps your muscles can handle that; however, other body structures may not. In the example of the school-aged girl, she had a slight build, low BMI, and carried a heavyweight over a long time. 

Weight Recommendations

  • Typically 10-15% of the child's body weight
  • Overweight vs. healthy-weight children – is there a difference?
    • 48 students (6-12 yo): 12 overweight/obese & 36 healthy-weight
    • Studied perceived load/fatigue, gait kinematics, RPE when carrying backpacks or trolleys of different loads
    • Found BMI does not impact rating of pain/discomfort
    • Study findings say obese/overweight and healthy-weight children have similar responses to backpack load.

(Orantes-Gonzales & Heredia-Jimenez, 2021)

Here is a study that looked at overweight children versus healthy-weight children. A statistic from 2016 says that 18% of children in that school-age range are overweight or obese. Logically, that would mean that larger children could carry a heavier load; however, some studies say that overweight children should have less in the backpack. They are already carrying more intrinsic weight, and that additional weight will put more strain on their extensor spinal muscles and increase their fatigue. Other studies contradict that and say that BMI does not factor into it.

This 2021 study supported previous studies that said BMI does not impact the rating of pain and discomfort. And in fact, healthy-weight and overweight children report fatigue during backpack carrying.

More On Weight Impact

  • As the center of mass shifts posteriorly, the body attempts to compensate.

(Abaraogu et al., 2017) 

The literature recommends that the backpack be only 10 to 15% of a child's body weight, endorsed by both the American Occupational Therapy Association and the American Physical Therapy Association. Before detrimental biomechanical impacts, the backpack can be ten to fifteen percent of a student's body weight. When making backpack recommendations, we need to look at additional factors other than a simple percentage or BMI. 

A study from the University of Nigeria on young adults (18 to 25) talked about weight's impact on backpack and posture. When students did their weigh-ins, they routinely carried more than 15% of their body weight. They also looked at other factors when recommending how to wear and how much to pack in a backpack. They also recommended looking at backpack design, how they are carrying it, the position and the placement of the items, and the physical characteristics of the individual.

They measured what happened with 15% of the body weight in a backpack, and immediately, there was an increased head and neck forward posture as the external weight pulled backward. With 10% of body weight, there was still an immediate forward trunk lean, and with 5% of the body weight, there were still physiological and biomechanical changes. They were putting barely anything in the backpack, but there were still changes in the body's center of mass. The center of mass changes posterior as soon as you put something on your back, and the body will attempt to compensate for that by pulling anteriorly.

Here is my oldest son wearing his backpack in Figure 2.

Figure 2

Figure 2. Different body changes can be seen depending upon the backpack's weight versus body weight.

There was nothing in it, but you can see he has an immediate forward-leaning posture. You can see the head and neck come forward slightly and a little bit of that C posture through the thoracic spine.

Need for Multifactorial Recommendations

  • Is the weight limit recommendation enough?
  • Multiple contributing factors to discomfort with backpack use
    • Biomechanical impact of wearing a backpack
    • Size/weight of children
    • Backpack content
    • Distance & duration wearing a backpack
  • Study of 444 children (7-12 yo)
    • Experiencing back pain or preventing back pain requires a multifactorial approach to problem-solving.

There are other biomechanical, physiological, and psychosocial factors. Studies prove that there is a recommended safe weight limit, but that alone is not effective in curbing the problems in school children. The other thing you have to take into consideration is compliance. We can buy the book bag and make the weight recommendations, but the students have to comply with wearing and packing it correctly.

A study in Malaysia looked at 444 students in the seven to 12-year-old range. They looked at many factors for back pain, as seen in Figure 3.

Figure 3

Figure 3. Factors for back pain.

This study looked at age, gender, how long it took to get from home to school, and how far it was from home to school. They looked at neck and back angles and took subjective ratings of the pain, including when it started, how long it lasted, and what type of pain it was. They also looked at the backpack contents and how much it weighed. Their findings warned that there were inconsistent correlations about body weight, BMI, and back pain, mostly due to children going through growth spurts during this time. There will also be a lot of variation in height and body types to consider.

They found that using a backpack of any weight will alter postural control in children. The weight of the backpack will decrease postural stability by pulling them posteriorly. The child then compensates by leaning forward or anteriorly at the head and neck. This change moves the individual's posture out of alignment and creates a muscle imbalance. The center of mass moved backward has to be compensated for by moving forward to align themselves over their feet.

They also found that their backpacks were carrying everything, including things that were unnecessary. Sometimes, the students could not control the content in their backpacks. For example, in Malaysia, the government decided on textbooks and educational requirements. The government recommended textbooks that exceeded 15% of their body weight.

Backpack Vs. Trolley

  • Does using a trolley change the weight recommendations or body alignment?
    • 49 students in elementary school
      • Walking unloaded
      • Pulling school trolley
      • Carrying backpack
      • 10%, 15%, 20% bodyweight
  • Findings included minor kinematic adaptations
  • Recommend avoiding >10% bodyweight if using a backpack and >20% if using a trolley 

(Orantes-Gonzales, Heredia-Jimenez, & Robinson, 2019)

An option to a standard backpack is a trolley or a wheeled backpack. The popularity of this option is increasing. This study found that about 5% of students in Texas, 15% in the Middle East, and 45% in Spain and Greece were using a rolling backpack. A rolling bag is a great option when carrying a heavier load; however, some schools discourage this for practical reasons like not fitting in lockers, a tripping hazard, or broken wheels.

  • Kinematic Adaptations
    • School Trolley
      • Asymmetrical task
      • Kinematic patterns close to normal walking
        • Adaptations of ↑ flexion of thorax, hip & pelvis (with 15-20% load of bodyweight) vs. unloaded walking
      • Can carry heavier loads with less musculoskeletal symptoms
    • Backpack
      • Symmetrical task
      • Does slightly alter kinematic patterns of walking even at low load
      • Higher incidence of musculoskeletal symptoms

(Orantes-Gonzales, Heredia-Jimenez & Robinson, 2019)

Orantes-Gonzales (2019) showed that pulling a trolley versus holding a backpack changed alignment. They looked at 49 students in elementary school and observed and measured them walking with nothing on. Then, they measured them pulling the school trolley or a wheeled backpack. Finally, they measured the subjects carrying the backpack with added 10%, 15%, and 20% of their body weight. 

They found some minor kinematic adaptations when pulling the school trolley versus holding the backpack. They stood by the recommendations of 10% or less when carrying a book bag, increased to 20% if using a trolley. The school trolley is not only a good option for heavier loads, but it is also not a bad option for lighter loads. There was very little kinematic adaptation seen even up to and over 20% of body weight. Whereas, if you carry a backpack, there was a change immediately.

The difference is that the school trolley is an asymmetrical task. You are pulling that with one side of the body; whereas, the backpack should be symmetrical with both straps distributing the weight throughout the back. They found that the kinematic patterns were close to ordinary walking when pulling the school trolley. There was some increase in the trunk, hip, and pelvic flexion, but that was with a 15 to 20% load compared to bodyweight versus unloaded walking. They also found that you could carry heavier loads with less musculoskeletal symptoms with a trolley. 

Backpack Design

Iran Study

  • Study of 2236 students (6-12 yo) in Iran
    • Sitting shoulder height; thigh thickness; shoulder breadth
    • Varied in between girls and boys in some age ranges
    • Should also consider the depth of backpack-changes body's COG*
    • Recommend backpack size should be based on age

(Mououdi, Akbari, & Mousavinasab, 2018)

Here is a study that looked at backpack design with body proportions. Backpack ergonomic design uses body proportions and anthropometrics, or the measurement of the body. They felt that some backpack manufacturers design backpacks for long-term use, but they do not consider that children grow a lot during that time. Think about the growth between starting school at five and finishing school at 18. You cannot make a "one size fits all" backpack with many different proportions. They also felt, and I would agree, that it is dangerous to choose a backpack based on style and look alone, even if on sale. 

One measurement they used was sitting shoulder height, as seen in Figure 4.

Figure 4

Figure 4. Sitting shoulder height and thigh thickness measurement.

Shoulder height is evaluated along with a measurement of thigh thickness. They used that to design the height of the backpack. Then, they looked at measuring shoulder breadth in Figure 5.

Figure 5

Figure 5. Shoulder breadth measurement.

They found that these three measurements varied between genders, with the shoulder breadth measurement consistently higher in boys than girls. The shoulder height was also higher in boys than girls, but only up until 10, and then it evened out with more similar measurements. The study also looked at designing how deep the backpack went and the amount of weight it could hold in relation to the center of gravity.

Indonesia Study

  • Study of 70 students in 6th grade in Indonesia
    • Observed backpacks of the students
    • Interviewed parents to see their role in backpack selection and awareness of the impact of backpack weight on their child
    • Weights and measures of children and interviewed where they feel discomfort when carrying a backpack
  • Results
    • Common areas of discomfort L shoulder, R shoulder, back
    • Recommendations of product design

(Sonna & Bella, 2018)

Here is another backpack design study done with 70 students in sixth grade. They observed the content of students' backpacks. They also looked at the children's weights/measurements, interviewed the children about where they felt discomfort when carrying their backpacks, and interviewed the parents to see their role in selecting the backpack and their awareness of backpack education. Did they look at what was in their kid's backpack? Did they realize the impact of what was in the backpack in terms of weight and wearing? The children reported areas of discomfort in their shoulders and back.

The average student weighed about 97 pounds, but their backpack weighed at least 12 pounds, which would be more than that 10% of their body weight. Based on this, they came up with particular ideas about the backpack design. 

  • Front pocket
  • Waist strap
  • Chest strap
  • Back pads – lumbar area and scapula
  • Lightweight but strong material

These are useful parameters when purchasing a backpack. They felt that having pockets, especially in the front, made it easier to find items and distribute the weight. And, by keeping lighter things in the front of the pack (or the back when wearing it) keeps less weight posteriorly.

They also looked at the necessity for a chest and a waist strap to help spread the load more evenly throughout the body. Waist straps help divide the weight between the back and the shoulders. The chest strap also helped hold and position the backpack where it should be, centered on the back and close to the body.

They also recommended foam back pads to improve comfort and prevent the load from inhibiting blood flow and circulation, nerve impingement, and pressure throughout the back. They originally thought that the kids should use smaller backpacks to allow for only the ideal weight there; however, they discovered that making the backpack too small made it very difficult for them to pack and arrange items. According to this study,
Figure 6 shows the perfect dimensions of the backpack for sixth graders.

Figure 6

Figure 6. Backpack dimensions for 6th graders.

It should be 35 cm tall, 25 cm wide, and about six centimeters deep with adjustable straps. I converted the centimeters into inches to understand it a little bit better.

Postural Changes

  • Increased trunk & neck flexion
    • Counterbalances load on the back
    • Increases force through the spine from 7x with weight + neutral spine to 11x with weight and 20° flexion
  • Pelvis adaptations
    • Reduced rotation and obliquity; increased anterior pelvic tilt
  • Limited changes in LEs
    • Changes are seen more so in proximal vs. distal joints

(Orantes-Gonzales, Heredia-Jimenez & Robinson, 2019)

Postural changes when carrying a backpack will happen throughout the body, mainly in the more proximal areas of the trunk and the pelvis. You see the increased trunk, and neck flexion as the center of mass is pulled backward. Usually, the spine takes seven times the force of what is in that backpack and transfers that through the spine. You lose the standard curves as you start to bend forward, flattening the lumbar curve and exaggerating the thoracic curve. With 20 degrees of flexion, the weight is multiplied by 11 times through the spinal column. There are also pelvic adaptations like reduced rotation and obliquity and increased anterior pelvic tilt to compensate for the shift in the center of mass.

Spine Biomechanics

  • Literature search
    • 22 studies with 1,159 (7-27 yo) looking at the impact of carrying backpacks on spine biomechanics
  • Results
    • A load of backpack impacts spinal posture, spinal load, demand on internal structures, muscle activity
    • Standing, walking, going up/downstairs
    • Can help make healthy backpack recommendations

(Suri, Shojaei & Bazragari, 2020)

Here is a literature search that involved 22 studies looking at spine biomechanics. It looked at over 1100 subjects in the seven to 27-year-old age range to see the impact of the spine biomechanics when wearing a backpack. Carrying a backpack puts considerable strain on the internal tissues of the spinal column and the things that support the spinal column. The study looked at the impact of backpack weight, the position of the trunk and spine in terms of posture, and muscle activity during different activities like standing, walking, going up, and downstairs.

The authors hoped that this additional knowledge would help identify how backpacks impact the spine. The study looked at the characteristics of appropriate backpack design, the negative consequences of backpack use, how to reduce spinal loads, and how to make backpack recommendations. They looked closely at what was happening to the spine in Figure 7.

Figure 7

Figure 7. Anatomical image of the spine.

We have been talking about the center of mass changes with backpack use. The student often moves into a flexion pattern in the trunk and the neck to compensate for the posterior force.

As part of the literature review, there was a study by Shaikh & Tendulkar in 2020. They acknowledged postural changes, but they also looked at both static and dynamic balance when wearing a backpack. They looked at 150 10 to 14-year-olds and found that balance scores were lower when wearing the backpack.

  • What happens to the spine?
    • Center of mass changes
    • Decreased lumbar curve
    • Muscle changes
    • Varies with movement activities

 

The lumbar curve becomes reduced once you move into a forward flexion pattern. The lumbar curve is crucial as it supports and protects the lumbar discs. Additionally, the extensor muscles of the trunk do not work as hard. However, in a flexed position, there will be muscle imbalances and changes. Additionally, carrying a backpack while walking will change spinal postures versus just standing. Postural changes will vary depending on how fast and far you are walking.

Interestingly, they did not see as many changes when going up and downstairs. One would think that activity would put more strain on the spine, but it did not.

  • Key Findings:
    • Changes in lumbar spine equilibrium and stability demands due to carrying a backpack lead to substantial increases in spinal loads even under activities that are not physically demanding."
    • "Researchers have observed deviations in trunk kinematics, lumbar posture, and trunk muscle activities while wearing backpacks during activities of daily living." 

Although we are not moving boxes or refrigerators, we still see a demand through the spinal column just from wearing something as simple as a backpack.

Healthy Backpack Recommendations

Let's talk about the things that we will put into practice or a way we can frame this. The AOTA had the idea of the "Pack It Light, Wear It Right" initiative. I love that slogan. I also want to endorse my motto of the three Ps of pick, pack, and position.

  • How to PICK
  • PACK
  • and POSITION a backpack?

These are three things to look at to make a healthy recommendation. It is not about the bodyweight or an economically correct backpack. You have to pick it, pack it, and position it correctly (AOTA, 2021; APTA, 2021).

Pick: Choosing a Backpack

  • Wide, padded shoulder straps
  • Consider the fabric
  • Chest and/or hip belt
  • Multiple compartments

The first P is to pick a backpack. The features to look for in a backpack are going to be wide padded shoulder straps. These two lovely young ladies are starting their school year and have new backpacks.

Figure 8

Figure 8. Girls with new backpacks.

I do not endorse any backpack as I know there are many types out there, and now you know the pros and cons of a lot of them. The bags in the picture are from LL Bean and Lezyne. They have some great features on them, like the wide padded shoulder straps, particularly on the purple backpack. These will help distribute the weight to prevent impingement in the shoulder and axilla areas.

The fabric is important because it is durable, lightweight, breathable, and quick-drying. If the child is caught in the rain, you want the backpack to quickly dry, so you do not carry any extra weight from the wetness. There should also be a chest and a hip belt.

The purple backpack has a chest belt that will hold the backpack in place and close to the body. On the right, the blue backpack has a waist strap, which will help distribute weight between the shoulders and the hips and throughout the back, rather than just up in the shoulders.

We are also looking for multiple compartments and adjustable straps.

Pack: Recommendations

  • 10-15% of body weight
  • Use compartments, distribute weight
  • Heavier items close to body/center
  • Keep sharp items away from the back

When packing, think about using only 10 to 15% of the body weight. If you do not know the children's weight, perhaps you can do a backpack weighing event. In this event, you can weigh both the backpack and the child to see if it fits within the ratio and the parameters. Remember, it should be 10 to 15% of the child's body weight. So your younger students, your elementary, younger grades don't weigh as much. And then as you get into the heavier loads that might need to be carried in your middle school and high school years, those children, luckily, are going to grow and increase their body weight a little bit that they can take more in the book bag, but still, 10 to 15% of the body weight.

The bookbag in Figure 9 has many good features. It has padded straps, but it does not have a chest or hip strap.

Figure 9

Figure 9. Another example of a backpack with some packing recommendations.

As awful as it is to say, I purchased the backpack for my son. In this image, I have highlighted how you should place the items. The heaviest items should go closest to the body near the core, which means more stability. And, heavy items should be no more than 10-15% of the body weight. You can pack lightweight items in the smaller pockets on the outside of the backpack. Another simple tip is to keep sharp items away from the back. My son also carries drumsticks to school with him, and we need to make sure that the drumsticks go somewhere where they are not going to poke him. Many backpacks now have padding for things like iPads and devices.

How you pack the backpack is essential. Again, during COVID times, children were carrying many things. A friend of ours told us that her slightly built daughter had so much in her backpack that she fell backward like a turtle. She had to have help to get up.

Positioning

  • Use BOTH shoulder straps
  • Consider using chest & hip belts
  • Should rest snugly against the back
  • Stay between shoulders and hip bones

For positioning, this is where the behavioral part comes in. We can educate the students, but they have to follow through. The first thing is using both shoulder straps. The backpack should be on both shoulders to make it symmetrical. The straps should be adjusted so that the backpack falls at the proper spot. Using one strap shifts that center of mass laterally to one side. The straps should also be snug, but not tight. You should be able to comfortably fit your fingers under the straps, but you do not want it to leave red marks or cause pulling through axillas. Figure 10 shows my son again.

Figure 10

Figure 10. Backpack position on the author's son's back.

I would probably raise this a few inches and have him pull his straps a little tighter. The bottom of the backpack should not go beyond the tailbone or be more than four inches below the waist. He is close to the line in this image. Consider using a chest and hip belt. The chest strap is going to keep the backpack snug against the child's back. The belt will take some weight off the shoulders and distribute it a little bit more evenly. It is important to make sure that the backpack is not too big that it will overwhelm or sag too low.

Warning Signs of Trouble

 

  • The backpack isn't easy to don/doff
  • Red Strap Marks
  • Tingling/ Numbness
  • It just feels HEAVY
  • Pain
  • Posture Change

Here are some warning signs. One of the easiest things to spot is that the backpack is not easy to take on and off. The child may struggle with the backpack's weight and have difficulty taking it on and off. Another sign is red strap marks. As OT practitioners, we check for red marks after splint use. This is the same idea with the straps of the backpack. Students may complain of pain, tingling, or numbness, or they may complain that the backpack feels heavy. We can also see posture deviations, with the backpack on or off. Posture is such an important thing to look at in children. We cannot help them if we are not checking this.

Parent and Child Education

  • Parents and children have a responsibility to ensure healthy habits
    • Choose the right backpack
    • Adjust straps for child's proportions
    • Monitor contents
    • Report any symptoms
  • Educational interventional programs needed
    • Students & parents
    • Teachers
    • School nurses
    • School administrators

Alami et al., 2020

We must take this information and disseminate this to parents and children. Parents and children need to take a shared responsibility to ensure healthy habits. It can be a family activity of choosing the right backpack. Make sure you consider all the information from this talk. I got a new backpack for my kindergartner, and I cut the tags off before he tried it on. Do not make this mistake. You should get the backpack on your child, adjust the straps for their body proportion, make sure that it fits properly, and is going to hold the items that they need.

You also need to monitor what goes in the backpack. Do they need all of the items, or are they housing an entire year of supplies in their backpack that should have been taken out every night? I can tell you stories for days of the things that I have found in my boys' backpacks. You can make it a family habit and routine.

Parents talk to kids about what is going on in school. Adding to the daily barrage of questions, the following can be added, "How'd your backpack feel? Are you comfortable wearing it? Can you take it on and off easily? What do you do with it in between classes? Do you get to go to your locker throughout the day?" We can also talk to teachers and other school personnel. Health and Phys Ed teachers and nurses would be great resources in this area. Occupational and physical therapy can also work together in the schools to support this initiative. It is an excellent opportunity for interprofessional collaboration. We can also do some backpack awareness and health promotion with the support of school administrators and even PTAs. A table at a back-to-school night with backpack awareness information is one example.

Body Mechanics

  • When picking up the backpack:
    • Get close to the backpack and keep in front
    • Maintain spinal curves
    • Bend at the hips and knees (instead of bending over)
    • Pick up first, then thread shoulders

Body mechanics is another area that we can educate students on. We stress body mechanics with our clients, and we can apply those same principles to donning and doffing a backpack. The child needs to keep the backpack close and in front to eliminate excessive reaching and twisting in the spine.

Figure 11

Figure 11. The author's son correctly picked up a backpack.

You can see in this first picture he is doing an awful job. He is using one hand and has a C shape in the spine. You can also see that the book bag is far from him, causing him to bend at the trunk instead of the hips and knees. He looks miserable, but he also is not happy I am taking his picture. You can see better ergonomics on the right side with him close to the backpack and bending at the hips and knees. He can use both arms to lift, keeping it close to his chest and maintaining a good spinal position.

The other thing that is recommended is that the child picks it up first and then threads their shoulders through. They should not do a significant twisting motion but rather two separate motions. Pick up first, and then get the shoulders through. They can also pick it up and place it on a higher surface like a coffee table, kitchen counter, or desk and then thread their arms through. 

Healthy Habits for Students

  • Fill water bottle at school
  • Take backpack off at bus stop or when waiting in the hallway
  • Monitor contents nightly – empty what is not needed
  • Wear BOTH straps
  • Organize supplies/binders for school day rotation (A-day, B-day, etc.)

Eatough, 2017

This was an article that came out of Baltimore. They talked to a student who carried 35 to 40 pounds of books every day. Between the notebooks, textbooks, water bottles, and sometimes even a second after-school bag, he was carrying 30 to 40 pounds of books all day. By choice, he was carrying this all day. While he had the opportunity to visit his locker and switch out supplies several times a day, he usually did not.

There are some things that we can do to help. Water bottles are heavy, sometimes up to 40 ounces. My kids' school's recommendation is to send at least 20 ounces or less in a water bottle so it does not take up as much room. One solution is having water filling stations so that they can take empty water bottles instead, and then they can bring them home empty.

It is also important that the student take off their backpack when waiting for the bus, in the hallway between classes, et cetera. Additionally, we need to monitor the contents of the backpack. This can be both the parent's and child's responsibility. Putting some of that responsibility on the child as part of a nightly routine may be helpful.

The backpack should be worn with both straps. Kids including mine do not think this looks cool, but both straps are needed to prevent injury.

Lastly, many schools rotate classes through the week. It is important for the student to remove items that are not needed for that day. It may be hard in the beginning for a freshman or new student to get into a routine with this, but it should improve over time. For instance, my son had to use a locker this year for the first time, and it took a while for him to get used to this. 

Support From School Administration

  • Utilize online textbooks when appropriate
  • Provide adequate time in between classes to visit lockers
  • Support backpack awareness events

School routines should be monitored and tailored to help support student health and wellness. Online textbooks or platforms may be used to reduce the number of actual textbooks being carried around school and from school to home. However, as we saw with the pandemic, if we lean on technology, this may also lead to inequities for students who have different levels of access to technology.

Another option may be both a desk and a home copy of a book to eliminate carrying them back and forth. Adequate time to access lockers between classes or to allow drop off of items like instruments in the band room can also decrease the load. Again, water filling stations would also help in this area.

Backpack awareness events at school can help to educate students and caregivers about the risks.

Backpack Awareness Events

Hold backpack awareness events. In this example, a backpack awareness event was held in the community with participants who got weighed and received education on proper techniques. They also had individuals who only grabbed some written education. In this example, there were 15 community participants and 15 students who came. Out of those 15, a quarter of them was at risk because of the way that they were carrying in their backpacks. They determined that even having one hard book weighed about three to five pounds, which put them close to that 10% bodyweight range, depending on how much they weighed in their age.

They also saw that students were carrying much more than just textbooks. They had musical instruments, extra gym shoes, lunches, umbrellas, and water bottles. I even had a parent who said, "My daughter is reading Harry Potter. Have you seen how big those Harry Potter books are?" They may also have to walk a long distance or climb many flights of stairs.

There are many free materials that you can disseminate in your school, via social media, or by going to the local news. These are great ways to promote occupational therapy and student health and wellness.

Promoting Occupational Therapy

October 27 is the International School Backpack Awareness Day. Again, there are many free infographics on the site that are easy and quick to digest. You can also follow the promoting OT initiative on Facebook, Instagram, Twitter, and LinkedIn. If you are planning an event, you can register with this website, and they may be able to support your initiative. 

Summary

  • Using a backpack – is essential to the student role
  • Potential to impact health and wellness of students
  • OTPs can provide education to students, parents, school communities about the proper use
  • Hold backpack awareness events – promote occupational therapy's distinct value!

In summary, this was an hour of talking about using a backpack properly. We have the ability to impact students in a positive way.

Questions and Answers

What about big backpacks for smaller framed children?

The girls highlighted were very small. They are children of an occupational therapist friend. She and her husband had a discussion about the proper size. He wanted them to have long-term backpacks, while she thought they were too big. They met in the middle. There are backpack vendors who do have different size backpacks. I know Pottery Barn is one of those that have different sizes for different age ranges.

How do you measure the child for the thickness of the backpack?

There was one study that talked about the thickness should be six inches, as a recommendation. I think the thickness has more to do with how you pack it than how big the backpack is.

What is the benefit of wearing symmetrical backpacks? Would we all benefit from wearing symmetrical backpacks rather than purses over one shoulder and modeling this for our children?

I agree. This is something that I am seeing more. One of the other areas I like to talk about is ergonomics and new moms. A new trend is backpack-type diaper bags. I am also seeing more backpacks used as handbags and computer bags. So, we have the opportunity to model that. Fashion is awesome, but function and health are really important too.

Living in the Midwest, a student may need a jacket in the morning, but by afternoon is in short sleeves. How do you adjust for that?

Welcome to the Northeast as well. This is where I feel like this is more related to a school routine. Perhaps the student can put it in their locker or hang it up throughout the day. They could be thread the sleeves through the straps or their waist to distribute the weight. You may need to help the child problem-solve some of these things.

References

 

Abaraogu, U. O., Ezenwankwo, E.F., Nwadilibe, I.B., Nwafor, G.C., Ugwuele, B.O., Uzoh, P.C., Ani, I., Amarachineke, K. Atuma, C. & Ewelunta, O. (2017). Immediate responses to backpack carriage on postural angles in young adults: A crossover randomized self-controlled study with repeated measures. Work, 57, 87-93.

Adeyemi, A.J., Rohani, J.M., Abdul Rani, M.R. (2017). Backpack-back pain complexity and the need for multifactorial safe weight recommendation. Applied Ergonomics, 58, 573-582.

Alami, A., Tehrani, H., Lael-Monfared, E., Sharifi Moghaddam, F., Gholamheidar, T.B. & Jafari, A. (2020). Ergonomic factors of school bags and their adaptation to the weight of students. Work, 65, 809-820.

American Occupational Therapy Association (2021). School backpack safety. https://www.aota.org/Conference-Events/Backpack-Safety-Awareness-Day.aspx

American Occupational Therapy Association (2020). Occupational therapy practice framework: Domain and process (4th ed.). American Journal of Occupational Therapy, 74(Suppl 2), 7412410010. https://doi. org/10.5014/ajot.2020.74S2001

American Physical Therapy Association (2021). 3 tips for backpack safety. https://www.choosept.com/resources/detail/backpack-safety

Eatough, A. (2017, September 5). A weighty subject: Local schools take steps to help students prevent injury by lightening their backpacks. The Baltimore Sun. Retrieved from https://www.baltimoresun.com/features/bs-fe-backpacks-20170901-story.html

Jayaratne, K., Jacobs, K. & Fernando, D. (2012). Global healthy backpack initiatives. Work, 41(Suppl 1), 5553-5557.

Mououdi, M.A., Akbari, J. & Mousavinasab, S.N. (2018). Ergonomic design of school backpack by using anthropometric measurements for primary school students (6-12 years). International Journal of Industrial Ergonomics, 67, 98-103.

Orantes-Gonzalez, E. & Heredia-Jimenez, J. (2021). Does schoolbag carriage equally affect obese/overweight and healthy-weight children? Applied Ergonomics, 90, 103236-106236.

Orantes-Gonzales, E., Heredia-Jimenez, J. & Robinson, M.A. (2019). A kinematic comparison of gait with a backpack vs. a trolley for load carriage in children. Applied Ergonomics, 80, 28-34.

Rose, K., Davies, A., Pitt, M. Ratnasinghe, D. & D’Argenzio, L. (2016). Backpack palsy: A rare complication of backpack use in children and young adults – A new case report. Journal of the European Paediatric Neurology Society, 20(5), 750-753.

Shaikh, A.A. & Tendulkar, S.G. (2020). Effect of backpack on static and dynamic balance in healthy school children: A comparison. Indian Journal of Physiotherapy & Occupational Therapy, 14(4), 1-12.

Sharp, O., Wong, K.Y., Stephens, P. (2017, May 22). Backpack palsy with Horner's syndrome. BMJ Case Report, 2017, bcr-2017-219402.

Sonna, K. & Bella, A. (2018). Designing an ergonomic backpack for sixth grade elementary school student sin Bandung based on the ideal weight of backpack load. MATEC web of conferences, 204, 03011

Suri, C., Shojaei, I. & Bazrgari, B. (2020). Effects of school backpacks on spine biomechanics during daily activities: A narrative review of literature. Human Factors, 62(6), 909-918.

Zeitlin, D. & Velasco, K. (2015, August 24). A backpack awareness day collaboration. OT Practice, 19-20.

Citation

Loesche, S. (2022). Back to school: Discussing the biomechanical impact of backpacks. OccupationalTherapy.com, Article 5483. Available at www.occupationaltherapy.com

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sara loesche

Sara Loesche, MS, OTR/L, CHT

Sara Loesche is an occupational therapist and an Associate Professor at Thomas Jefferson University in the Occupational Therapy Assistant Studies Program. For the past 10 years, she has taught a course in information literacy as it applies to occupational therapy in both the academic and practice environments. This has led to presenting on the topic at both state and national conferences.

 

 



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