The most common cause is a hip belt that isn’t doing its job — either the pack doesn’t have a genuine padded, load-bearing hip belt, or it does but isn’t tightened enough to actually sit the weight on the hips. Past roughly 15-20 kg (33.1 to 44.1 lb), shoulders alone struggle regardless of how padded the straps are.
Torso length mismatch is the second common cause: a pack sized wrong for the wearer’s torso length puts the hip belt at the wrong height, so even a well-padded belt can’t transfer weight properly. This is worth checking against an actual torso measurement rather than assuming a “one size fits all” pack fits every body.
If the pack genuinely has no hip belt — common on lighter travel backpacks under 40L — the shoulder straps are doing all the work by design. In that case, packing lighter, or upgrading to a pack with a load-bearing hip belt for anything carried a genuine distance, are the two practical fixes.
Last reviewed 26 August 2026