There were different ways to perform a front kick in Okinawa’s past karate. Egami Shigeru, a senior student of Funakoshi Ginchin, in his marvelous book “The Way Of Karate Beyond Technique” vividly describes one of them.
“The form of the foot in the front kick when I began practice was with the toes folded down.The part of the foot that struck the opponent was the first joint of the big toe. Since the toe had to be strong – otherwise they might be broken – we were made to practice standing, and even walking with our toes folded, as shown in figure 96. Having mastered this, we practiced jumping with our toes in this position, and I was eventually able to perform a double kick (ni-dan geri) in this fashion. Although this kick was performed in demonstrations because of it’s interest, it had no relevance go training, and few practiced it because it was so painful”.(1)
One believes this was a method of older style kicking from when karate developed. Placing the entire force generated by the kick into the first knuckle joint made for a smaller more intense kicking surface. Stories of a kick, making a student on the receiving end ill unto death, seem more credible. Then the change of karate to train young men in University or secondary schools made new kicking forms, such as the ball of the foot, less painful and less dangerous to one kicked, a most rational change.
Engami describes other changes in karate, when more must have been similar to the Itosu origins.
This is not the only older method to kicking. Christopher Caille in his article on his site FightingArts.com describes another tradition. http://fightingarts.com/reading/article.php?id=407 . Other traditions still use these older kicking traditions, Ueichi Ryu karate comes to mind. However in most contempory karate the newer kicking traditions predominate.
(1) Page 53