"Children are just learning to sit unsupported at about 9 months of age. Until this age, infants have not developed sufficient bone mass and muscle tone to enable them to sit unsupported with their backs straight. Pediatricians advise against having infants sitting in a slumped or curled position for prolonged periods."
Yeah. That's why we put them in hard plastic baby buckets and drive them around in strollers and cars. Come on. Why is it okay except on a bicycle?
Also, "just learning to sit unsupported"? Sure. T. was walking at 8 months (cruising at 7). Definitely not enough muscle tone there! I didn't find out about the Wee Ride until the end of June 2006, which implies T. was 10 months by the time he was in it. I'd _like_ to go out with A. before that, but we'll have to see how things go. There's a Bobike Mini on the way, and the WeeRide is buried in the basement somewhere.