Here’s an intro to some of those baby-hauling packs.
With all of our carriers, the baby rides behind the adult’s shoulder blades, facing front. Each also had a kickstand that allowed the pack to be set on the ground with the baby still inside. While we found all of our models to be fairly comfortable — thanks to padded shoulder straps and an adjustable fit around the waist, sternum and torso — not all made for such happy trails.
I once saw a guy hiking up a hill that about gave me a heart attack carrying one little girl in the pack on his back, and another in his arms in front. Dude had some serious legs.