I just want to say, this thing is GLORIOUS!! I got an exercise ball at walmart (much cheaper than a birthing ball and same exact thing) and it has made my hips and lower back feel amazing. Ive had a lot of pain issues due to previous sciatica and just general hip pain but sitting on the ball and rolling back and forth makes it feel so much better. I highly recommend trying one if you're far enough that your doctor approves. I sit on it when folding laundry or doing things with my kiddo instead.of kneeling or bending over, it really is a world of difference.
Re: Birthing ball (giant exercise ball)