Structured baby carriers have both shoulder straps and a waist strap that distributes the weight on the wearer to allow for greater comfort over extended time periods. Many babywearing experts feel that babies should never face out because they are not in the proper seated position (for comfort and spinal support) but rather a dangling position, hanging by their crotch. Some companies, like Ergo have now designed a front facing carrier that has an actual seat for baby to avoid "the dangle".
Many structured carriers have comfort features like padded shoulders and infant inserts to accommodate longer wear times for both parent and baby.
Structured brands with proper ergonomic support for baby (no dangle) include Ergo, Beco, Boba, Onya and Lille.