Champion jumping around after clicking bug [GAMEPLAY]

So I've been playing League for about a year, and having this problem for about a month or so, it's just now I've gotten around to posting it. Whenever I give a movement command, my champion jumps around and makes it hard to play. As you can see in the video, if I give a command across the map and follow my champ, it won't jump around, but when I give another command, it does. I don't have this problem AS MUCH after minions have spawned but it still happens and makes it EXTREMELY hard to trade because I don't know where my champion is.

This happens to me on every map, every time I play, with ~75ms ping. I've tried uninstalling and I've tried repairing. I regularly get about 300 FPS

Computer Specs:

Intel i7 3770k 3.4GHz 16GB RAM Intel 180GB SSD NVidia GTX970 23" AOC 1080p Display

Has anyone ever had this problem and if so is there a way to fix it? Halp pl0x I <3 League