Hi, M.!
Sounds like you are having the same problem that I had w/ my first, when I used the Baby Bjorn! Once my daughter hit about 12 lbs, it killed my back & shoulders! That's when I developed THING-A-MA-SLING. They are ring slings that can be custom-made. Each comes with 3 built-in pockets (for wallet, keys, cell, sippy cup, etc...), are machine washable & dryable and are extremely comfortable! I design them with a special "shoulder tuck" system that automatically spreads the fabric accross your shoulder area & accross most of your back. That way, you have LOTS of muscles all working together to reduce strain & increase comfort.
I have worn my son for 10+ hours, 3 days in a row (when we went to Disney) and was fine! Just yesterday, I wore him for 2 hours straight (he's 16 mos now) while I was carrying tons of heavy stuff & was perfectly fine! I used it regularly w/ my daughter till she was over 3 years old!
I am offering 10% off right now by using coupon code "HH08" during checkout, if you're interested. My website is www.ThingaMaSling.com . Also, if you're anywhere near the Easton area, I'd be happy to meet you some place so that you don't have to pay for shipping.
I know I am biased, but I truly do find these slings to be insanely comfortable and extremely versatile! Please let me know if I can answer any questions for you at all!
Thank you so much & Happy Holidays!!!
A.
www.ThingaMaSling.com
1-877-SLING-99