Kick boxing can be defined as a martial art that uses western boxing for hand strikes, and eastern martial arts for kicks. This definition is a little too simple, as that definition would include arts like Savate, Muay Thai, and Sanda as kickboxing, when no one thinks of them as being the same thing.
With the exception of Sanda, all of these existed long before the term “kick boxing” existed, so we don’t call Savate of Muay Thai kickboxing.
Sanda isn’t considered kick boxing because it includes throws (as does Muay thai to a lesser degree).
Japanese kickboxing was invented in the 1950’s when there were some full contact challenge bouts between karate fighters and Muay Thai fighters. The karate fighters who were willing to get in the ring with the Thais were tough, hard core competitors, mostly from Kyokushin, and they did OK, but lost more often than they won.
Some of the karate masters in those days decided to incorporate muay thai techniques, in particular the kicks. Mas Oyama, the founder of Kyokushin, is said to have added all the thai kicks to the Kyokushin kick arsenal, and he even modified the standard roundhouse kick to become a kick which was a hybrid of the karate roundhouse and the muay thai roundhouse.
Meanwhile, America developed its own version of kick boxing in the 1970’s when some of the top karate point fighters, Joe Lewis in particular, wanted to compete in full contact karate matches.
At that time there were promoters who believed that full contact karate could become a popular sport, even though the general public had never really been interested in watching no contact karate tournaments.
This was called “full contact karate”, but the fighters wore boxing gloves and quickly figured out that the most effective punches for full contact were boxing punches. Leg kicks were not allowed, and knee strikes and elbow strikes were banned.
There have been theories that the promoters believed that limiting kicks to above the waist would make the bouts look flashier to the audience. However it is just as likely that the karate point fighters who pioneered this new sport were already used to kicking above the waist, and just needed to learn a little boxing in order to compete in this new sport.
The early bouts actually didn’t have much kicking, because the fighters who were used to competing in no contact point fighting did not have the extreme conditioning of boxers, Thai fighters, or of the MMA fighters of our own time.
These early American kick boxers found that it was easier to get both points and knock outs with boxing punches than with kicks, especially since low kicks were not allowed, and it was much less tiring to focus on hand techniques. The early tournaments actually required a minimum number of kicks that had to be thrown in each round, in order to avoid point deductions.
Interestingly, at the time that American kick boxing was invented, most of the top point fighting competitors were either Korean stylists, or used mostly Korean style kicks. In the US, karate tournament competitors had always borrowed techniques from other Karate and Tae Kwan Do styles. So “American kick boxing” was in actuality a combination of western boxing and mostly Korean karate kicking techniques.
As these fighters became much better conditioned, the number of kicks, as well as the effectiveness of the kicks increased. The top fighters of the era were Joe Lewis in the heavyweight division, Bill Wallace in the middle weight division, and Benny Urquidez in the light weight division. All of them used a lot of very effective kicks.
Joe learned Karate in Okinawa when he was stationed there in the military, and got his black belt in an amazing 9 months. He favored the side kick and ridge hand in his no contact tournaments, and continued to use the side kick in his kick boxing fights.
Joe was a very skilled fighter, was tough as nails, and had knockout power in his hands and feet. He also trained with Bruce Lee, and Bruce was even his corner man and trainer for some of his kick boxing fights.
Joe was unbeatable in both point fighting and kick boxing, but towards the end of his career, he realized that despite all his successes he really hadn’t made much money, so he decided to try professional boxing. He had one fight against a mediocre boxer and was soundly beaten, which shows how dominant boxing is for hand techniques. However, Joe was probably past his prime then.
Bill Wallace was originally a Judo competitor but he was forced to quit Judo after he damaged one of his knees. When he switched to Karate he had an outstanding kick boxing career as a middleweight. He fought out of a horse stance with his bad leg as far away from his opponent as possible, and he used mostly kicking techniques, all off of his lead leg.
He devised his own unique style where he used the same chamber for the roundhouse kick, side kick, and hook kick, so that opponents had trouble telling which kick was coming at them, until it was too late. Bill had outstanding speed and flexibility in his lead leg and scored many spectacular knockouts with lead leg head kicks. He also liked the lead hook punch and the jab.
Benny studied and obtained black belts in 9 different martial arts. He had some really good kicks that he used effectively in the ring, including spinning kicks and jumping kicks. He was so dominant in the US in his weight class that he started touring around the world, and was willing to fight anybody, anywhere, with great success. Eventually he went to Thailand to compete against the Thai champions.
Because Benny was a lightweight, he wasn’t too big to make the weight classes in Thailand. He had 3 bouts, one he won in spectacular fashion, breaking several of the opponents ribs with a spinning back kick, in one he was beaten up pretty good, and the third fight was very controversial. After these 3 fights, Benny never fought the Thais again.
Because leg kicks were found to be so effective, American Kick boxing was eventually replaced by other kick boxing styles which used leg kicks. Some competitions, like Glory, also use knees and some limited clinching. Also karate style kicks have become much less popular than Muay Thai kicks in kick boxing, as well as in MMA.
For people who have already achieved a high proficiency in karate, learning boxing can allow them to use their own American kick boxing for self defense.