Weak Left Hook.

Ok at first i had serious trouble throwing a left hook but now i can throw one but it just feels weak. And when i do a left hook on my heavy bag i feel like im gonna tear my shoulder. My straight left is good(im a right handed southpaw) and my uppercuts are good. My left hook to the body is ok but its not what i call powerful. All i know is i dont know whats wrong with it. Some1 help. I mean im throwin it good. I dont knot im leavin it up to you guys.

Before you throw it roll your right shoulder forwards as if your throwing a right hand.

your left shoulder will be back no so when you throw you'll get more leverage. You musn't be throwing it good otherwise you'd be punching your weight and there'd be no problem... ;) USE YOUR LEGS :P :)