Yeah, you aren't suppossed to wear orthotics for a whole day right away... You're supposed to wear them twice a day for 30 minutes, and then every day increase by 30 minutes. So the next day is twice for an hour, and so on until your times run into eachother in the middle. Once you're used to them they're great, but you can't just go for it right away. Even getting new ones you can't wear the new ones all day right away, it's faster to adjust but not instant. Mine have 3mm foam on top of the hard insert, I got the sports model or whatever with thicker foam because I'm 6'6" and pretty heavy...