7 Things About Backpack Safety You’ll Kick Yourself for Not Knowing

By Jennifer Norton Graham, MPT, Certified Schroth Physical Therapist (Physiotherapist), Scoliosis, Kyphosis & Posture Specialist with 23 years of physical therapy experience, Mom, Entrepreneur, Practice Founder & Owner, Flamenco Dancer.

The information provided in this blog is not intended for use in diagnosis, management or treatment of any medical condition and is solely for educational purposes.

1.  Backpack Weight 

The weight of the backpack matters. Research has shown that backpack loads of greater than 10% of the body weight of the wearer, for shoulder harness backpacks, should be avoided. For trolley or rolling backpacks, avoiding loads more than 20% of the body weight of the wearer is recommended. Furthermore, according to Drzaƚ-Grabiec, Justynaa et al., “even a load of 10% of the body mass may induce negative changes in spinal posture.” Additionally in a study by Sahli et al, even backpack loads of 10% of body weight may alter the balance of someone living with adolescent idiopathic scoliosis.  

Higher weighted backpacks have been associated with reports of pain, fatigue, skin changes and discomfort. As well as impacts on inspiration and expiration breathing muscle strength, decreased trunk range of motion,  changes in walking patterns, changes in posture including increased arching in the lower back, increased loading to the spine, depending on the carrying position both flattening of the upper back or rounding of the upper back can be found, rounded shoulders, forward head and increased neck or cervical lordosis. 

Add all these changes in addition to having scoliosis, kyphosis or changes in posture, it becomes evident that backpack weight or load is something to consider in backpack safety.  Pal et al. recommends that students should be carefully screened for possible ‘high load-high exposure time’.

There are strategies to help reduce the weight of the backpack. 

Download the Freebie Backpack Checkup Checklist Here 

2.  Backpack Carrying Position

The weight of the backpack is distributed by the carrying position of the bag.  There are mono (one) strap bags which are worn across the body with diagonally placed straps.  

There are shoulder harness backpacks that are worn on either both shoulders or one shoulder depending on the individual's choice. If a backpack is worn on both shoulders, then the load of the backpack has two contact points to help spread the work between both sides of the trunk/torso.

However, if a backpack with two shoulder harness straps is only worn on one shoulder, then this contributes to uneven load weight bearing through the shoulders, torso/spine, ribcage, hips, pelvis and feet.

For those carrying a backpack on one shoulder and also have the complexity of scoliosis, then carrying a backpack may contribute to spinal or trunk movement into the scoliosis curves.  This then places increased asymmetrical loading onto a scoliosis spine/torso.  Also in the case of scoliosis in which the pelvis (if looking front to back or back to front) may already be positioned off center to one side, left or right.  The individual’s pelvis may shift further asymmetrically either toward the load of the backpack, or away from it, to help offset the asymmetrical carrying position and load of the bag. If the child or teen is growing during critical growth years, there may be increased risk of postural changes associated with backpack carrying position.

What about carrying the backpack at the back or front of the body or both?  According to D. H. Chow et al., a backpack carried at the front of the body  in line with the 12th thoracic vertebrae or bone of the thoracic spine was shown to cause less impact on spine deformation and repositioning in school children.   It was hypothesized that alternating between carrying the backpack at the front of the body and the back of the body,  may be a strategy to manage the effects of carrying a backpack. 

There are more strategies to help promote a healthy backpack carrying position. In general, it appears that a double shoulder harness backpack is preferable to a mono strap and that the double shoulder harness backpack is preferable to wear on both shoulders vs. one shoulder. 

Learn more & Download the Freebie Backpack Checkup Checklist Here 

3.  Backpacks Can Alter the Way We Walk

Walking has several components such as how far we step, how much time a leg is in the air versus how long it is on the ground, how the whole body responds to walking, in the swing of the arms or torso, the rotation in the torso and posture as well. 

Many changes occur when we wear backpacks. Interestingly, wearing a backpack can contribute to decreases in stride length, step length, speed, cadence, the way the arms swing, the way the trunk or torso twists, and postural changes from three dimensions (front to back or back to front, a side view and an aerial view or looking from the top of the head down to the ground in standing).   

Scoliosis and Kyphosis due to the alterations in the internal structure of the body and also the associated postural changes and muscle imbalances, may experience changes in the mechanism of walking combined with changes associated with wearing a backpack. 

According to Orantes-Gonzalez et al., rolling backpacks or trolley backpacks were found to produce “fewer changes in the child's kinematics and, therefore, resembles more closely their movement when walking free of any load, compared to carrying the backpack, even when it weighs very little.”  It appears that with regard to walking with a backpack,  that a rolling backpack helps to preserve the movement of walking better than a double harness backpack. 

Walking with a weighted backpack is also considered a form of exercise and is called “rucking” and has been shown to be used in military training and social fitness.  However, the impact of a weighted backpack, the way it is worn/carried and the impact on walking are factors to consider whether it be for fitness or daily life as a student or professional. 

Learn more & Download the Freebie Backpack Checkup Checklist Here 

4.  Backpacks Impact Respiratory Muscle Strength on Inspiration and Expiration

Monostrap backpack, or one strap worn diagonally across the body, was found to restrict respiration efforts. Vieira & Ribeiro suggested in their article that a “double strap backpack is preferable to a mono shoulder strap backpack”.  However, regardless of mono or double strap backpacks there are impacts to the breathing mechanism associated with wearing a backpack in general. 

Breathing patterns, the perception of exercise stress and breathing discomfort were all impacted with having loaded backpacks (Phillips et al.). In a study evaluating backpack loads on soldiers marching, it was found that, as the weight of the backpack or mass, and exercise intensity increased, the degree of limitation in the flow, the exhalation component of breathing and overall breathing muscle fatigue and the efficiency of breathing or respiration reduced (Armstrong et al.).

In another study by Faghy et al., found evidence that constant speed walking and time trial exercise with a 25 kg thoracic load or weighted backpack caused a significant inspiratory (inhalation) and expiratory (exhalation) muscle fatigue.  Applying this research to daily life, in students wearing a loaded backpack speed walking from the car or bus pick up/drop off line to school, or speed walking between classes or the busy professional wearing a backpack and speed walking to take the subway or speed walking down a hallway to a meeting, that impacts on the breathing mechanism and muscle fatigue can be considered. 

Fitness programs or military exercises incorporate this knowledge of the impact on the breathing mechanism, through the use of weighted or loaded backpacks for the sake of a workout.  The backpacks in this case are utilized as training tools or exercise tools as well.  Shei et al. evaluated and found that there was a potential for loaded backpacks to be a useful strategy to optimize performance due to the intention to strengthen and build endurance in the diaphragm and accessory inspiratory muscles.  However in the same review Shei et al.  concluded that loaded backpack exercise “has a distinct, deleterious effect on exercise performance and capacity.”  

Knowing that wearing a backpack has an impact on the breathing mechanism, may allow the wearer to complete breathwork or begin a program to intentionally strengthen the breathing muscles to attempt to counteract the breathing compromise associated by wearing a backpack.

Learn more & Download the Freebie Backpack Checkup Checklist Here 

Check out the Kickstart Scoliosis & Kyphosis Postural Evolution Course which includes breathwork exercises!

6.  Backpacks Impact Your Posture

Depending on the load or how long the backpack is being worn, changes in your normal resting posture may occur.  Examples might include leaning forward in your torso to accommodate for the extra load on your back, rounding the shoulders forward, or protruding the head forward, or increased arching of the lower back tilting the pelvis anteriorly or forward. In a study by Hell et al. it was referenced that in children and adolescents the activity of the muscles on either side of the spine was decreased, indicating that the backpack was being “carried passively” versus actively.  The body can be very clever and find balancing patterns that may not recruit or activate muscles in an optimal way, yet still carry out an activity such as carrying a backpack. 

Another example of carrying posture changes may include a forward shift of the whole pelvis/hip complex, protruding abdomen, shift backwards in the upper torso which creates an asymmetry in the postural column from a side view. 

With adequate and active postural support in the body from front to back and three dimensionally, including abdominal wall support, the loads of the back pack can be better supported by improved postural alignment and core stability. By activating the core/abdominal wall while wearing a backpack in adolescents, the forward lean and perceived exertion of wearing a backpack can be reduced. 

Learn more & Download the Freebie Backpack Checkup Checklist Here 

Need a Kickstart for Posture? Check out the Kickstart Scoliosis & Kyphosis Postural Evolution Course which includes postural exercises!

7.  Mechanics of Picking Up or Placing the Backpack Down Matter 

Dynamic lifting up or placing down of a backpack or has many variables.  Gravity, inertia, the backpack load, compressive and shear forces, and the postural muscle forces and stability all present factors to consider when lifting up or placing down a backpack.  There are two lifting techniques: stoop and lift (straight knees round back) and the squat and lift (knees bent and back straight) that continue to be studied and evaluated.  Ergonomically, the squat and lift being most notable, for a safer lifting strategy.  

How do you retrieve your backpack? Stoop and lift or squat and lift technique? For parents or students, how does your student lift their backpack? In the community, it is common to see the use of stoop and lift with the torso sidebending to one side or combining with rotation is observed.  It is also common for an individual to grasp the same strap and put on/take off in the same manner multiple times a day.  

In a study by Bazragari et al., comparing stoop and lift vs. squat and lift found that torso, lower back or lumbar and pelvis rotations were larger in the stoop and lift strategy vs. the squat in lift.   This is a significant finding applied to lifting a backpack especially when combining the three dimensional complexity of scoliosis, kyphosis or postural changes.  If a student or individually lift’s their backpack with a stoop and lift technique and in a repetitive movement pattern, reaching for the same strap each time could facilitate movement into the torso rotations associated with scoliosis. 

Utilizing the squat and lift technique appears to be the most ergonomic solution when lifting a backpack up or placing it down. 

Learn more & Download the Freebie Backpack Checkup Checklist Here 

8.  Backpacks Can Provide Biomechanical Feedback to the Student or Professional 

Our skin is the largest organ in the body and covers the body’s entire surface.  We have receptors in the skin, muscles and joints which help to provide information about the position of clothing or objects on our skin.  Proprioception through the input of receptors in the joints, muscles and skin help tell us where we are in space or where a limb or body part is in space. This is relevant to wearing a backpack especially in the example of wearing a double harness or wearing both straps of the backpack.  

Since it has been established that wearing a backpack can impact the posture of the body when wearing a backpack. A strategy to help minimize postural impacts of wearing a backpack may include positioning the backpack optimally, but also through the feedback of the contour of the pack against the back of the body and pelvis.  For example, if there is increased weight of the backpack on the sacrum/pelvis lower back and upper back, but then there is a gap or air space between the lower back and the backpack, then using the feedback of the backpack against the back, one could strive to be sure to feel the entire pack along their back. This could be complimented by activating the core abdominal wall support and providing more support for the loaded backpack.  Additionally the sensation of the straps on the shoulders or pressure of the shoulder blades against the back of the backpack, one could strive to pull the shoulders back, tighten the shoulder straps to help make the backpack flush with the upper back as well. 

Using the backpack surface and the back of the body contact points to establish the most balanced contact is a strategy that can be utilized to help promote a more optimal backpack position. 

Learn More and Download the Freebie Backpack Checkup Checklist Here 

References/Resources 

1. Drzał-Grabiec, J., Truszczyńska, A., Rykała, J., Rachwał, M., Snela, S., & Podgórska, J. (2015). Effect of asymmetrical backpack load on spinal curvature in school children. Work (Reading, Mass.), 51(2), 383–388. https://doi.org/10.3233/WOR-141981
2. Sahli, S., Rebai, H., Ghroubi, S., Yahia, A., Guermazi, M., & Elleuch, M. H. (2013). The effects of backpack load and carrying method on the balance of adolescent idiopathic scoliosis subjects. The spine journal : official journal of the North American Spine Society, 13(12), 1835–1842. https://doi.org/10.1016/j.spinee.2013.06.023
3. Chow, D. H., Ou, Z. Y., Wang, X. G., & Lai, A. (2010). Short-term effects of backpack load placement on spine deformation and repositioning error in schoolchildren. Ergonomics, 53(1), 56–64. https://doi.org/10.1080/00140130903389050
4. University of Granada. (2019, July 2). Maximum weight children should carry in school backpacks. ScienceDaily. www.sciencedaily.com/releases/2019/07/190702112708.htm
5. E. Orantes-Gonzalez, J. Heredia-Jimenez, M.A. Robinson. A kinematic comparison of gait with a backpack versus a trolley for load carriage in children. Applied Ergonomics, 2019; 80: 28 DOI: 10.1016/j.apergo.2019.05.003
6. https://www.healthline.com/health/fitness/rucking
7. Vieira, A. C., & Ribeiro, F. (2015). Impact of backpack type on respiratory muscle strength and lung function in children. Ergonomics, 58(6), 1005–1011. https://doi.org/10.1080/00140139.2014.997803
8. Phillips, D. B., Stickland, M. K., & Petersen, S. R. (2016). Physiological and performance consequences of heavy thoracic load carriage in females. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme, 41(7), 741–748. https://doi.org/10.1139/apnm-2016-0002
9. Armstrong, N. C. D., Ward, A., Lomax, M., Tipton, M. J., & House, J. R. (2019). Wearing body armour and backpack loads increase the likelihood of expiratory flow limitation and respiratory muscle fatigue during marching. Ergonomics, 62(9), 1181–1192. https://doi.org/10.1080/00140139.2019.1629638
10. Faghy, M. A., Shei, R. J., Armstrong, N. C. D., White, M., & Lomax, M. (2022). Physiological impact of load carriage exercise: Current understanding and future research directions. Physiological reports, 10(21), e15502. https://doi.org/10.14814/phy2.15502
11. Shei, R. J., Chapman, R. F., Gruber, A. H., & Mickleborough, T. D. (2017). Respiratory Effects of Thoracic Load Carriage Exercise and Inspiratory Muscle Training as a Strategy to Optimize Respiratory Muscle Performance with Load Carriage. Springer science reviews, 5(1-2), 49–64. https://doi.org/10.1007/s40362-017-0046-5
12. Hell, A. K., Braunschweig, L., Grages, B., Brunner, R., & Romkes, J. (2021). Einfluss des Schulrucksackgewichtes bei Grundschulkindern: Gang, Muskelaktivität, Haltung und Stabilität [The influence of backpack weight in school children: gait, muscle activity, posture and stability]. Der Orthopade, 50(6), 446–454. https://doi.org/10.1007/s00132-020-04047-8
13. Bazrgari, B., Shirazi-Adl, A., & Arjmand, N. (2007). Analysis of squat and stoop dynamic liftings: muscle forces and internal spinal loads. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 16(5), 687–699. https://doi.org/10.1007/s00586-006-0240-7
14. Kramers-de Quervain, I. A., Müller, R., Stacoff, A., Grob, D., & Stüssi, E. (2004). Gait analysis in patients with idiopathic scoliosis. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 13(5), 449–456. https://doi.org/10.1007/s00586-003-0588-x
15. Gao, C. C., Chern, J. S., Chang, C. J., Lai, P. L., & Lung, C. W. (2019). Center of pressure progression patterns during level walking in adolescents with idiopathic scoliosis. PloS one, 14(4), e0212161. https://doi.org/10.1371/journal.pone.0212161
16. Li, J. X., Hong, Y., & Robinson, P. D. (2003). The effect of load carriage on movement kinematics and respiratory parameters in children during walking. European journal of applied physiology, 90(1-2), 35–43. https://doi.org/10.1007/s00421-003-0848-9
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