I live on the fit ball atm with Jovie in the HAB during the day, or I wait for her to get to a deeper sleep & then sit down. I have been having a sore back lately too and its pretty hard having her in the HAB and chasing Matilda at the same time, but if I put her down for too long she gets pretty cranky, so I'm rather her feel secure. I sit on the fit ball & check out BB while bouncing away.