A Common Kicking Mistake that Robs Your Power and Can Tear Your ACL

By Matthew Schafer
Copyright 2013, All Rights Reserved

About two years ago I was talking to a woman who wanted more than anything to earn her black belt. When she talked about it she got very animated and it was obvious that she had a real passion for Karate, but then she told me that due to a torn ACL she hadn’t practiced in over a year.

She told me that shortly after she earned her brown belt she was sparring during class when she got too excited; facing one of the senior black belts in the school she wanted to put on a good show so she recalls stepping forwards and throwing a right front kick as hard as she could...and then feeling as sharp pain in her left knee and falling to the ground. She had torn her ACL in the left knee and found out she would be in recovery for about a year and a half. Unfortunately, when I looked into it I found this was not that uncommon for martial artists.

About seven years ago man named Tom came to my school. He had earned his black belt from a local Taekwondo school and wanted to see what else was out there. I began giving him private lessons and he quickly found that a key difference between my school and his old school was that in my school we spend a great deal of time hitting things whereas his school spent most of their time kicking the air. Having spent so much time kicking the air his body wasn’t used to dealing with impact of really hitting something with his kicks and punches and as a result when he would kick a bag or kicking shield he would pretty much just bounce off. It took a little while to modify his kicking technique but soon he could stand in one place and drive his foot through a pad without being pushed off balance.

Tom still attended class at his Taekwondo school here and there and after one class he reported that the sudden improvement in his kicking technique was not winning him any friends in that school. Apparently, the entire class formed two lines and the first line held a kicking shield so the second line could practice their front kicks. He said everyone in his line was kicking the shield in a steady rhythm...except for him. Everyone else was hitting the pads with one kick after another but every time Tom kicked the pad he knocked his partner back a step and a half so his partner had to step back up and reset breaking the classes rhythm.

The problem came when Tom had to hold the pad for his partner and the guy found that, kick as hard as he could, he could not knock Tom backwards. To make matters worse Tom was a slender man in his 60’s who rarely came to class and his partner was a muscular man in his mid 20’s who attended class twice a week so as the younger man kicked harder and harder only to see Tom not move he got madder and madder as his ego became more and more bruised.

Both instances above have the same element in common, the lady at the start of this article didn’t know this kicking secret and became injured while Tom did know it and developed a front kick that was the envy of his class.

Tearing the ACL is, unfortunately, a somewhat common injury in the martial arts and it tends to happen the same way in most cases. The cause is often kicking while your base foot is pointed at your target. When you kick you throw your body weight forward, so your weight starts pretty much over your heels and then as the kick extends and your weight goes forwards and your center of gravity travels up your base foot towards your toes. As your body weight goes forwards you become unstable so you dig the ball of your foot into the ground to push backwards and keep your balance, and this does two things; first it pushes your body and your body weight away from the kick preventing you hitting as hard as you could have and transferring all of your body weight. This is one reason people lack power in their front kicks and one of the main reasons that, try as he might, the younger guy couldn’t knock Tom backwards.

The second thing that happens is that when the ball of your foot digs into the floor pushing you backwards your upper body is still going forwards. The result is everything above your knee is going one direction and everything below your knee is going the other and you end up with anywhere from a little bit of knee pain to a torn ACL.

How do you fix this, simply look to Tai Chi. The best footwork in the martial arts comes from Tai Chi, and what do they do in Tai Chi before they throw a kick? They turn their base foot out. If you’re going to throw a right front kick you should first turn your left foot outwards 45-90 degrees from your target. By turning your base foot out it opens your hips giving you a better range of motion and then when your weight transfers forwards it simply goes over your heel allowing your entire body to travel into the kick. Turning your base foot outward protects your foot and your knee from strain and allows you to put all your body weight and musculature into the kick.

Tom knocked his younger partner back when he kicked the kicking shield not because he was bigger or stronger than him and not because he generated more force when he kicked, in fact the opposite was true. Rather by using correct structure he was able to transfer more of the force into the kicking shield which is a great example of working smarter and not harder.