Every time I get up out of bed or stand up after sitting on the sofa for a long time my knees are so stiff and sore. I know this is from kneeling to change my wee one as I just keep my change mat on the floor and from bath times but I have no room for a change table and don't want to use the kitchen table. Anyone else suffer from stiff knees? Any advice? My wee one is 17 weeks now by the way.