Proposal for a novel backpack component: Movable Lumbar Pad

Thanks for sharing.

This reminds me of the old North Face Black Magic backpack.  It had a external frame that connected to the hipbelt via a flexing plastic strut.  That allowed the belt to flex as a hiker walked.  The pack weighted a ton as I recall.  It never caught on and North Face was a small player in the pack market behind Kelly, JanSport, and the new internal frame packs.

The connection point between the hip belt and back panel of the pack would have to be strong.  I wonder if a single center strap from the bottom seam of the pack body to a floating hipbelt would achieve the same movement? Would having the bottom of the shoulder straps anchor into the hipbelt help or hurt this movement?

interesting idea,

Scott

Doesn’t any kind of hipbelt impede your movement? I find relatively good support without impeding of movement by having runnig style shoulder straps that support off the ribcage. I guess that only works to a certain weight, though. Aarn Packs has one of the better designs incorporating a hipbelt by having pass through sliding shoulder straps which allow the load to rotate freely with your hips even though it is still weighting them down.

that is a very interesting concept you have there. i am sure it is valid, and efficiency can be gained.
i use both a Aarn backpack with it’s extreme use of isolating elements, and a McHale pack, with it’s industrially severe structure. they both carry well in their intended ranges.

along the lines of the Aarn, with all it’s sliding parts,  and straps, and tubes, and channels, and all of the details that let it carry so joyously well, there is a cost. that cost is that one really needs to be aware when putting it on that everything is correct. it is for example, quite easy to toss an arm thru the wrong place, and thence be on the incorrect side of a strap. although super comfortable at lighter weights, the system is unworkable at higher weights over the course of a long trip.

Aarn has for several decades been working effectively towards greater efficiency by proper balancing loads front to back, and by allowing several areas of pack attachment to be zero-sum, so as one side may tighten, the opposite loosens.

for what it’s worth ; in light of my experience, your theory is correct on that some energy is consumed when the pack locks the torso in rotation. under enough load (expedition type loads) the locking will go so far as to change ones walking gait. so that might seem not ideal. however … it has also happened that when using a pack with a nice comfortable rotationaly isolated lumbar support, that situations occur where the mass of the pack decides that it wants to go off on it’s own, as if i had given it permission. those situations can be dangerous in a very immediate way. example ; rock hopping across a creek, the load shifts and throws off the aim of my leading foot. into the river i then go. possibly slipping off of a rock. it’s just not a safe experience.

i suspect the rotating belt would be very nice up to about 20 kilos, and after that it might increasingly become a liability. or perhaps the load-shifting is a combination of both the belt rotation coupled with the shoulder strap isolation system. i don’t know.

carrying efficiency is not perhaps so simple as it looks sometimes.