The question at hand: Should your fist be horizontal (palm down) or vertical (palm sideways) when executing a hook punch? The reason I ask is that in my TKD class, we have always been taught horizontal; this seems natural to me, but I have no other formal training. Recently, I took a Muay Thai class, and the instructor corrected me to a vertical fist when doing a hook (palm would be facing my face at the end of the technique). This, to me, seems to restrict range of motion, and lacks power. But, then again, I'm not the expert. Opinions, please.
On a “classic” hook the palm is facing down. You twist the wrist to release power as with most punches. I tend to teach that as a basic. I do teach a palm toward you punch that is a combination of a upper cut and a hook. The only thing about throwing a hook with the palm toward you is you must be careful not to flap with it. You must make sure you get your body behind the punch. I have seen a lot of fighters that throw it with the palm toward them slap with their hooks. I have also seen fighters that throw with the palm toward them use good body mechanics and throw very powerful hooks. So it comes down to what is most important in all punching, sound body mechanics.
I was trained to hook with vertical fist. Never really asked why oldshadow - we call that a "45 punch", if i understand what you are describing correctly. comes in at a 45 degree angle to either body or chin...
We often work on the hook... using both our palm down and our palm towards us. Each punch is a little bit different... but the movement behind the body is almost the same. Most of the power of your hook comes from getting your body in the right place to throw it effectively... we were told to throw the punch we feel "works for us"
I’m not sure what you mean by small and longer hooks? If it’s the angle at the elbow then for good power the forearm needs to be at a 90-degree angle from the elbow.
Six of one, half a dozen of the other I was taught both ways and teach my guys both as well. There are times that we do the old style inverted fist(thumb down) rounding blow as well for long range.