Updated: Apr 27
Hello, Ray here!
Erica is a Taekwondo athlete from Acme Sabertooth as well as a budding actress.
She has a reasonably high standard of athleticism and very nice sidekicks (kudos to Joyce for training her up).
Erica was struggling with her 540 reverse kick (Cheat 720 hook if you will), so we worked together to bring her 540 reverse kick to the next level.
This is the end product :
And this is what we started with:
If you're keen to understand more about the thought process behind how I destructured a reasonably complex movement pattern such as 540 reverse kick and how I employed a series of movement drills to treat her issues using biomechanics, do read to the end!
Analysis of Issue
inefficient use of momentum during the K step
Internal rotation and hip flexion of the right hip joint, resulting in the reverse kick coming out earlier than expected
Good hip abduction, but lacking hip extension to finish the reverse kick
Focus on drills to reinforce the following movement patterns:
Internal Rotation of Right hip + Right Hip Extension, instead of Internal Rotation of right hip + right Hip flexion
Abating the amount of hip abduction to improve hip extension during the reverse kick chamber, by priming a back thrust type chamber instead of a sidekick
The series of training took 5 sessions to complete, with a week of rest in between each session (she has other taekwondo and stunt training as well, so this is done to ensure she doesn't overtrain).
The general methodology I used was to focus on simple movement patterns and then gradually build up to include more complex movement patterns.
1. jumping back thrust
The Taekwondo kick known as the jumping back thrust is a powerful technique that involves explosive lower body movement and precise control of balance and body position.
Biomechanically, the kick involves a series of coordinated movements that start with the practitioner lifting their lead leg and pushing off the ground with their back leg to jump upwards and backwards. During this jump, the practitioner maintains an upright posture and shifts their weight towards the back leg while simultaneously pulling the kicking leg towards their body.
Once in the air, the practitioner then extends their kicking leg forcefully towards their target, while simultaneously rotating their hips and torso to generate additional power. The kick is completed by retracting the kicking leg back towards the body and landing back onto the ground in a controlled manner.
The focus of this drill is to prime the hip extension of the athlete as she extends her leg through the kick.
Putting the focus on the left leg, the movement sequence is:
Knee flexion (right after jumping off)
The more knee flexion you have when you chamber, the more elastic potential energy you are storing in your posterior chain (mainly hamstrings).
You would see a key difference in the quality of the 540 reverse kick if the hip extension is done before knee extension after the chamber in the next few segments.
2.Switch back thrust
This improvised drill, which I call the "Switch Back Thrust", focuses on a simultaneous right hip flexion to place the ball of feet below the center of gravity when she is chambering and then extending her left hip and knee into the target.
Switching of the hips during 540 reverse kick is one of the most under-appreciated movements that is biomechanically efficient. It uses a falling, thrusting, and catching movement pattern so most of the momentum goes upwards and forwards along with the kick so that the kick goes higher, rather than across and catch in a twist and kick movement pattern (which induces the athlete to fall due to excess momentum).
3. Half twist switch back thrust
This movement pattern "half twist switch back thrust" mirrors the 540 reverse kick, after the k-step and jump are done. If you are facing similar issues as Erica during your 540 kick, you might find this drill apt.
From this angle, you might be able to see a very clear "fall, thrust, and catch" mechanism. This enables Erica to engage in her hip extension that is previously lacking, as her hip abduction is too dominant.
When the exercise or drill replicates the same movement pattern that is required for a specific task, it allows the athlete to develop one's muscle memory and reinforce good habits (techniques), leading to better performance during actual execution.
4.540 back thrust
Now we add the k-step into the previous drill. By far, this step is the hardest step I've seen across the athletes I've coached.
Adding momentum into a reinforced muscle memory usually changes it, as the trigger of the muscle memory prior to this drill is a stationary jump.
However, if the visual cue remains the same, what we can do is slow down the setup so the athlete regains proprioceptive control of one's environment, and then scale up the speed when the athlete gets more comfortable with increasing power.
The result after the first session
Though not fully optimized yet, we could see that she is
kicking to the front
has significantly more hip extension than hip abduction, which enables her to kick through
5. Jumping 540 2 targets ( pop jackknife)
In the third session working on the 540 reverse/hook kick (cheat 720 kick), we worked on enabling hip extension of her right hip as she is undergoing internal rotation of her right hip.
The focus of this drill is to ensure that the heel of the right leg touches the target, before switching and engaging in the reverse kick.
Internal Rotation of right hip and hip flexion
Previously, we could see that the Internal rotation of the right hip + hip flexion "locks" her hip up resulting in a kick that is too early. You could observe that her heel is going to her hips rather than the target.
Internal Rotation of right hip + Hip Extension
With this drill, the key difference is that there is more hip extension on her right hip, which allows for her heel to reach for the target - most importantly giving her the opportunity to execute the "fall, thrust and catch" mechanism.
6. Applying muscle memory into kstep
Once I could see that she doesn't have too much hip flexion as she is undergoing internal rotation of her right hip, and there is sufficient hip extension when she does her reverse kick, the work here is complete.
While there is another approach to training, which I call the brute force approach ( similar to brute force algorithm) where the athlete trains until one understands how to do it- we focus on a conscientious approach of employing biomechanics (human physiology and physics) into technique training.
This was achieved in the fourth session.
This was achieved in the fifth session.
Some comments about the execution:
The difference between the 2 videos above was that in the latter, she extended her knee prior to extending her hip.
The former results in a sharp reverse kick, while the latter results in a wider reverse kick. Both are nice, just that the execution is different. Athletes can choose their own method of execution.
We are pivoting into a strength-training first approach to improve the effectiveness of our technique training.
It is infeasible that the athlete has a lower level of conditioning of one's body than the level of conditioning required by the technique.
The level of conditioning of the athlete's body should always be higher than what is required by the technique, for a stable training outcome.
Single Leg Squat (similar to Polloquin Step Up).
This is a deceleration drill that I employ to teach students how to take impact. In a joint flexion scenario (ubiquitous for landings), we want the extensor muscle group to be undergoing eccentric contraction under a load and it should be executed slowly & controlled.
In this case, the quads and glutes are undergoing eccentric contraction under her body weight and an additional 7.5kg weight.
Weighted Hip Flexion
You might notice that we are using the belt on top of the tib bar, and that is not out of disrespect. There is a sharp metal bracket at the top of the tib bar which pierces through the skin upon heavier weight, so the belt is used as a cushion to prevent injury.
Power = Force x Velocity.
To increase an athlete's power production facilities, we first have to increase the amount of force produced and capacity to absorb the same or greater amount of force, and then increase the velocity at which the force is produced.
Weighted Hip flexion is an additional exercise we do to improve hip flexor strength, which helps in bringing the knee up during the 540 turning kick.
My intention in producing this article and "open-sourcing" this knowledge and the way to use biomechanics to teach increasingly complex movement patterns is to inspire a new generation of Taekwondo players who are able to excel in Freestyle Poomsae with the help of biomechanics, which I feel is the area of growth for Taekwondo.
I'm sure with more attention to taking care of the growth of the athletes and helping them achieve optimal performance, the Taekwondo scene will see a rejuvenation of glory and honor for Singapore.
You don't have to be in Korea to pick up these skill sets.
We are a team of coaches that is movement pattern/club agnostic and we are marching towards a vision of "Trick Forever".
If you'd like to work towards kicks like this, do come for a trial class.
We have a "Bring a Friend Trial" going on, where you could purchase the trial lesson for 1 pax and have another pax join you. Do ask the other pax to create an account on our website and send us a DM with the email that you/your friend used to create the accounts.
If you manage/own a gym and would like your students to be exposed to movement patterns that gives an edge in the Freestyle Poomsae competitions, do leave a message below- I'm happy to help.