From the third or fourth tightening it worked quite well with the back buckle (when equipped only back buckle undergo only then tighten the shoulder straps; undress first make the shoulder straps loose then detach the buckle).
My daughter is now 1 year old and the stretcher is used almost every day; sometimes over long distances. Although I have of small-to-back problems, I could wear them to jerzt easily on your stomach, because the weight is virtually divided on hips and shoulders. Now with 8kg it is time to carry them on their backs; but I am too clumsy and my daughter quite active, so I've always needed the help so far. But it also wants to be practiced.
My conclusion after 6 months, and a stretcher advice: From the seat Age ERGObaby is good. Before unfortunately too much pressure on the small back is exercised since it is not sling fabric and therefore too rigid and the back straps are attached to the back panel. The little baby back is therefore "just pressed" and can not be rounded. In addition, the web width can not be shortened and the legs may be too much for smaller children ausseinandergedrückt. The newborn insert should also not be the ideal. For newborn best use a sling which best adapts to the baby's body.