What's wrong is doing an Olypic lift variation seated! It's not your fault for trying to fing something new, but some variations just don't make sense. Power cleans are used to develope explosive strength through integration of the ankles, knees, hips, core, spine, shoulders, and a small contribution from the biceps. the key word being "explosive". Unless you are a wheel chair athlete and your coach insists and has demonstrated this to you,take my advice and do them standing, please.