When you think about an effective backpack load distribution to the lower back, what will you focus on?
I thought it will be achieved if lumbar pad is well fitted to the lower back keeping its fitting state dynamically.

So, I designed the pad shape considering anatomical aspects, and its motion components that realize 3-axis rotation + sideways slide. And regarding the motion components, it was made based on the motion of bones in gait.

Pelvis periodically rotates in the 3-axis direction when walking and trunk moves sideways. And a horizontal relative displacement occurs between the thorax and pelvis. This movement probably causes the backpack to swing in the sideway directions to the user’s body and an unbalanced and excessive load on each shoulder due to the hind leg side of the pelvis pushing out the backpack. Furthermore when using hip belt, it might cause discomfort and skin chafing to users.

The Proposed lumbar pad rotates in the pelvic range of motion and absorbs the holizontal relative displacement between the thorax and pelvis.

Through the experiment that measures the interface loads with 3-axis tactile sensors, I confirmed the load distribution effect of the movable lumbar pad while walking. Shoulder load will be more effectively reduced if a hip belt is attached to this movable lumbar pad.

Thank you for reading this post.
I have released it on my YouTube channel.
You can watch the pad motion there.
Please check it out.

YouTube: Backpack Researcher