My ankles/feet were killing me for about a week when I started wearing these, but that's because they work different muscles in my feet than I was used to. Make sure to stretch your calves, ankles, and feet regularly as you get used to them, and drink plenty of water to avoid muscle soreness. You may want to use insoles for a bit, but they're designed to be worn without them.<br /><br />The soles are perfectly non-slip, but make sure you clean out the soles regularly (as with any non-slip sole).<br /><br />All in all they're a solid, inexpensive kitchen clog.