I think like many things there is a potential risk. Just because you use a jolly jumper doean't mean your child will definately walk on tippee toes, have back issues etc. But, there are associated risks, particulalry if it is not used correctly. It is good to be aware.

Kuriaza- Thanks for pointing out the current research. It is always good to be informed. I have heard a bit about it, and was always cautious to only use it for short periods and at the correct hight.