Why when hikers are tired is it easier to hold the straps of our backpacks?

Question

When I start a hike, my hands and arms are free and easy. Towards the end I always find them clutching the straps of my backpack. Why?

Edit, for clarity: I always use a waist strap. I’m not talking about using my arms to lift weight off my shoulders. I seem to end up holding my shoulder straps, elbows pointed downwards, almost pulling the backpack downwards onto my shoulders and tighter against my back.

In: 310

Answer 1

Every good backpack I’ve used has had some lifter straps above the shoulders that pull some weight off the shoulders. Pulls the pack closer to your neck, helping the shoulders.