The Evolution of Innovation

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The Evolution of Innovation: How an effort to improve children's health modernized backpacks

The Problem

child carrying conventional backpackAll one has to do is conduct a simple online search for “children’s health problems caused by backpacks” to find hundreds of articles about the adverse physiological effects on children caused by heavy loads and inadequate packs.  For decades physicians, chiropractors, and orthopedic surgeons have reported seeing countless numbers of child patients suffering with neck and back pain, microstructural nerve damage, as well as damage to the soft tissue of the shoulders.  Some of the more serious effects noted have been diminished dexterity in the hands and fingers.  It was for these reasons that Andrew McUmber, as a senior at the Auburn University’s school of Industrial Design, set out to create a solution to help improve this lingering problem.


The overall concept was simple-develop a healthier way for 90% of the population to carry heavy weight.  This led to the design of two frame systems that can be used by both children and adults alike.


There are five main criteria that underpin McUmber’s frame designs—improved posture, better weight distribution along the shoulders and back, stabilized cargo, supported lower back, and controlled dynamic shock.

Average dimensions for children of different ages.

The profile of the frame incorporates a curve that is designed to fit the natural contour of the spine, improving posture along the thoracic and lumbar regions.  Relying on Henry Dreyfuss’ anthropometric measurements (percentiles of normal sizes) for different age groups and genders, the sizes of the two frames span a range of torso lengths that encapsulate most (90%) children and adults.

The frame is designed to sit above the hips.  This places more emphasis on the larger hip muscles for support, rather than the soft tissue of the neck and shoulders. The design incorporates a cargo deck to fully support the weight of the load.  This feature stabilizes the load and maintains it in a constant position above the hips, while eliminating sagging from unsupported cargo. Multiple attaching points allow for 2.5 inches of variation for the location of shoulder straps to further ensure proper fitment.  The overall shape allows for more contact between the surface area of the back and the frame’s foam padding.  This ensures that constant pressure is more evenly dispersed over the entire surface of the back, thereby reducing friction and pressure points.  This helps to better distribute weight and reduce the strain on smaller neck and shoulder muscles. 

List of features of packrabbit pack framesAn integral part of the frame’s design is the pivoting oversized lumbar support, which is positioned in parallel to the cargo deck.  The large surface area applies even pressure to the lower back to fully support the lumbar region and keep the weight balanced and steady, a feature that is especially important while pivoting forward or backward in conjunction with ascending or descending terrain.  The shape of the oversized lumbar support was curved to fit the back from the center outward, providing equal support for narrow- or wide-hipped users.

To tackle lateral motions along uneven terrain, the frame incorporates a racking feature that is designed to work in concert with natural hip motion.  This is accomplished through the use of a slotted-tension system that glides freely from 0-30° to absorb shock as weight is transferred between the hips.  By maintaining the supported weight against the entire back throughout the motion, the load remains steady and dynamic shock is greatly reduced. Interchangeable tensioners allow for variations of resistance based on individual comfort and support requirements.

An added feature of the design is an integrated low-profile chair.  The cargo deck maintains the frame in an upright and slightly reclined freestanding position.  From this position, rotating the pivoting lumbar support downward 90° along its axial point exposes a slightly elevated low-profile chair.  Working in tandem, the slightly reclined and elevated position creates a neutral pelvis and lumbar spinal posture that is both supportive and comfortable for long periods of time.


Inventor, Andrew McUmberMcUmber’s patented frame designs represent years of research and development. Working closely with medical professionals to develop and test prototypes, the first full-sized commercial design was completed in 2005.  Several years later, in 2013, he improved upon his design and created a smaller commercial version.  The attention to detail and innovation are immediately apparent in both designs.  Reduced neck and shoulder stress, improved posture, enhanced lumbar support, better weight distribution, and more control over dynamic shock are all hallmark successes of McUmber’s frame system.