Why BackTpack Works
Unlike backpacks or messenger bags, BackTpack, with its balanced side bags, applies the load to the body’s vertical axis, thereby eliminating posture distortion and decreasing the effort required to carry the load, in obedience to the laws of physics. The load feels lighter and you stand straighter.
The Center of Gravity
When we support a weight, we have a new center of gravity -- the combination of our body's center of gravity plus the center of gravity of the weight we are supporting. When what we carry is balanced left-right or front-back, or is on top of the head, its center of gravity aligns vertically with ours.
However, if the weight is off-axis (in front, to one side, or behind), we must lean away from the load to keep our new center of gravity over our feet so that we don't fall. Posture must change to accommodate the bag we carry, and the heavier the load, the more we must lean.
Line of Force
The force applied to support the load must go through the center of gravity of the load. So again, when the load is balanced, or on our head, the supporting force is simply equal to the weight we carry, and in the opposite direction: straight up!
When the weight is off-axis, we must pull in a direction such that the direction of the pull goes through the center of gravity of the load. This introduces a horizontal component to the force, which is added to the weight, meaning that more force is required. Put another way, a heavy backpack requires you to lean forward and pull forward with your shoulders. This is why you see hunched shoulders and forward heads with backpack use. With the same load in a BackTpack, you eliminate the forward pull.
It is also the reason that people say, "The load feels lighter!" when they try on a BackTpack loaded with the contents of their conventional backpack.
Fourth generation BackTpack for children and adults. Dual side-bag carrying system that conforms to the natural body structure to train good posture.
Available in three designer colors (Pewter/Mimosa shown)
- One size fits adults and children from age 7 and up. Redesigned back panel and strapping system fits Small, Medium, and Large body sizes.
- Highly adjustable to accommodate different body types.
Two large compartments, one on either side
- State-of-the-art crinkle nylon fabric
- Padded bottoms and side panels against your body for durability and comfort
- Briefcase handles for easy carrying by hand, with snap fasteners for holding handles together
- Heavy duty construction; bounce tested with 50-pound load for 48 hours
Multiple pockets inside and out (12 in total)
- Cell phone pocket on outside
- Pen pockets inside each compartment
- Large zippered pocket inside each compartment (9)
- Large open-topped pockets against body (1)
- Small outside zippered pockets on the right and left (4)
- One bottle holder on outside (6)
- Magnet and snap closures
- Inside loops for securing hydration packs (9)
Adjustable shoulder straps
- Padded for comfort
- Secured in place by an adjustable sternum strap, so they never fall off your shoulders
- This unique feature is essential for spinal health. When you sit or squat while wearing the bag, the LAP-STRAP immediately transfers the weight of the bags off the shoulders and spine and onto the thighs without having to remove the shoulder straps. This prevents unhealthy load-bearing through a flexed (rounded) spine.
- Allows bags to remain accessible at your sides if you choose to remove shoulder straps while seated
Integral hip-loading belt
- Takes the weight of the bag off of your spine and shoulders if/when you need to do so for comfort or because of injury
- IMPORTANT! Use of the hip-loading belt reduces the posture training effect of the BackTpack carrying system
Locking system for desired hip width (2)
Headphone port on each side (8)
Hang loop for storage on a hook
After multiple uses in a variety of settings I feel confident recommending the BackTPack to every onsite evaluator. The BackTPack evenly distributes all of my analysis equipment while keeping it easily accessible. I can climb equipment, move through confined spaces, and traverse facilities for hours without fatigue or risk. The BackTPack makes it easy for me to get into position, get my measurement tools out, and complete as task assessment all in the time it takes colleagues to struggle maneuvering roller bags or accessing equipment from backpacks. The best part, I never find myself searching for my equipment, because I never have to set it down, simply slide it back into its compartment or clip it back on the strap.
Must have for anyone performing ergonomic or job site analysis.
Leslie A Alvarez, ATC, CEAS