>>2138627I made that pic to illustrate that internal frame packs are inherently inferior to an external frame when it comes to regular hiking.
The internal frame was made for climbing so that when you lean forward the center of gravity is lower on your back instead of pushing down on your head and shoulders.
However, when you walk upright, having the center of gravity lower hanging off your back, instead of on top of the shoulders, you start leaning forward and break your posture.
Green lines illustrates a more ideal position. By centering the weight on top, you decrease the leverage pulling you back and thereby can maintain strong posture and preserve energy.
