I'm not sure what causes it but my rooster named Broken Foot has two toes that were broken when he was a chick. I'm not sure if he came that way or if they broke when I picked him up one time and tried to hold him. Anyway it does not seem to hamper his style any. He is pictured in my avatar currently.
It is a birth defect in the egg, sometimes the toes will be crooked when the baby grows and moves around in the shell. If it is running around and acting fine, then I would just keep an eye on it. If the chick is immobile, I would put it down. A chick that can't walk around is a dead chick.
I find it strange that your males have the crooked feet. Can they walk, are their toes pointing outward or inwards?
From my experience with baby chicks, do NOT help them hatch unless you know for sure you need to in order to save a life. A chick will naturally turn in its shell and peck all the way around the perimeter of the egg to finish the hatching. A straight, almost perfect crack is the sign that the chick is healthy, and therefore has a better chance at surviving. Crooked, sharp edges are an indicator that the chick might be tired or has problems. Sometimes the chick will die before it even hatches all the way (learned from experience myself). A chick will also "pip," or crack the shell before it is fully ready to come so do NOT help it. Signs of struggling are hard for the human in charge of the chick, but in general it means the chick will be stronger. Anyway, I digress and I'm going off topic.
I had one incident where a chick got crushed... literally, the shell was damaged by the hen's breastbone while the chick was hatching. I ended up scrubbing the crap out of my hands and did a little "operation." It was tiresome, and there was blood due to the fact that I had to clip the umbilical cord attached to the yolk. Thankfully the chick is doing fine now, but I only helped it due to the fact that I did not want the hen to peck and eventually kill the brood. Again, do not help the chick unless you know for sure it will survive. My chick that got crushed was already pipping through and doing fine. I know if you have a 3/4 pure bred chick the mortality rate is higher; they can die very easily since it's a weaker breed. Perhaps it's the temperature of the brooder? For chicken eggs temps needs to be at 95 degrees F. and not exceed 105 F.