Punching - Inability to make correct fist
I've recently taken up learning Muay Thai and I've been training for awhile. The gym that I learn at never really taught us the specifics such as making a correct fist and where to contact with. I've been researching it abit my self lately, and I'm reading that you should contact with your knuckles (which ones is debated) and the wrist and arm should be in alignment.
I agree with having a straight wrist, although I am having alot of trouble. It seems for me, if I punch with a straight wrist, the first point of contact is always my small finger knuckle on my index finger (you know the little knuckle thats close to the tip of your finger). Whenever I clench my fist and look at it from the side, that small fore-knuckle always sticks out way past my primary striking knuckles. This is a problem, because the only way I can contact with my knuckles is by bending my wrist downwards, and this seems dangerous to me as my wrist is out of alignment.
Is this a technique error or is my index finger simply too long or out of shape? It causes me pain when training on a heavy bag often, can I still punch correctly or is my hand structure wrong?