Note postures: BACKPACK BODYPACK
A BACKPACK HAS 4 BIOMECHANICAL FLAWS
1. A backpack creates forward lean.
The offset load forces you to bend forward to keep your revised centre of gravity centered over your feet. With all the weight behind leverages are created which increase the forces acting on the body above that of the weight itself. So a 16kg load exerts 20kg or more on the body.
You lean forward to reduce these forces and keep body + pack weight centered over your feet. These extra forces act on the spine to distort its natural shape. They combine with the forward lean to increase muscle tension throughout the body, especially in the neck, shoulders, back and thighs. Your gait patterns are affected and more energy is consumed with each step.
2. A backpack a downward and a rearward force on your shoulders.
If you loosen the shoulder straps on your backpack the pack falls backwards. To prevent this you keep the shoulder straps tight and brace your shoulders forward. This consumes energy and tires the body. Even the best hipbelt cannot alleviate this situation.
3. A backpack places weight on the back of the hips and none on the front.
With no balancing weight on the front of the pelvis a rotating forces is created around your hip sockets, pushing the pelvis downwards at the backside. You unconsciously use muscle tension to resist this force. This is one of the reasons that lower back pain is common in people carrying heavy backpacks.
4. A backpack acts as a lever on your back, making body movements unwieldy.
Because the center of gravity of the load is well behind that of your body, the load acts as a lever, resisting the natural flow of body movement. This effect is most noticeable in sports that require a lot of body movement such as skiing. Your balance is completely altered by your pack and once a ski turn is initiated, the load wants to keep on swinging around reducing your control and jeopardizing your balance.
A FLOWMO BODYPACK ELIMINATES THESE FLAW
1. A FlowMo Bodypack restores your natural upright posture.
By choosing the largest volume Balance Pockets available for your Aarn pack model and by packing your heaviest most compact items in these Balance Pockets and your light bulky gear in the pack, you can achieve a body-centered load. This means that the center of gravity exactly matches that of the body, both vertically and horizontally. Now your posture is unaltered by the load and there is no forward lean. Strain is eliminated. As weight is balanced front and back no leverages are created on the spine. The forces on the body are only vertical, consisting of the weight alone (16kg).
2. A FlowMo Bodypack eliminates the rearwards force on your shoulders.
Just as the pack wants to fall backwards away from your shoulders, the Balance Pockets want to fall forward. The 2 forces cancel each other out so there is no rearwards pull on the shoulders and no energy consuming forward bracing is needed. Any load on the shoulders acts in a vertical direction. This can be reduced to zero by loosening the shoulder straps so that all of the load is taken on the hips. Then the spine is no longer under compression and the shoulder straps act as load locators rather than load bearers.
3. A FlowMo Bodypack evenly distributes the weight on the back and front of the hips.
The connection of the front Balance Pockets to the shoulder straps is a sliding connection, so that none of the weight in the Pockets goes onto the shoulders. It all goes onto the front of your hips. This balances the load on the back of the hips from the pack, eliminating all rotating force on the pelvis. The pelvis stays level without muscle tension. Strain in the lower back is eliminated.
4. With a FlowMo Bodypack the center of mass is one with the center of gravity of the body, making movements easy.
Balancing weight around the body’s center of gravity is the foundation for natural body movement, natural balance and load stability. For free and fluid movement to be possible under load, the harness of the pack and Balance Pockets must cooperate. Our patented flow motion systems interlink the harness parts allowing your torso to move and twist freely.
“The counterbalance system eliminates postural stress on the torso and shoulder girdle. My kinesiological tests on a patient who had back surgery showed no stress induced by using the pack.”
— Jay Wilson, D.C., USA Chiropractor and Backpacker
The research suggests energy savings with Balance Pockets start with loads as low as 3 kg.