Or in other words. The biggest mistake you can make when working towards your Middle Split.
All beginnings are hard and especially starting to work towards the Middle Split can be difficult. The further you are from a flat middle split the harder it is to stretch as you simply don’t know where to begin to stretch and what to engage. While I have had my flat middle split for well over 10 years now I do remember this feeling of complete powerlessness and I am reminded of it daily when training towards new goals and dreams. The desperation of not knowing how but wanting so badly to improve paired with youthful recklessness can easily push you to be less careful, making mistakes that could and should be avoided at all costs.
Bending the knees in the Middle Split is about as big as you can go when it comes to things to do wrong.
There are 2 things that happen when you bend your knees in the Middle Split.
First of all you are cheating your hips down without actually improving your middle split. You might think that your flexibility is improving because the distance to the floor is getting less over time but you are actually really not. In order to improve your middle split you need to stretch your adducteurs and your hamstrings. Neither of them can be efficiently targeted with bent knees.
Secondly, bending the knees in your middle split stretch is really unhealthy and frankly quite dangerous. Whenever you do a middle split you place pressure onto your knees from the inside pushing them to bend towards the outside. If your legs are fully engaged and you actively straighten your knees they are tight and therefore protected from bending outside and injuries. Letting the leg muscles go loose and allowing the knees to bend does not only eliminate this protecting mechanism but places them in an even more dangerous angle.
So here is what I want you to do instead. Walk your hands back a bit towards you. You can even grab yoga blocks or a chair to pop yourself into a more upright position.
Now here you should be able to lock your knees. If you are still not able you will have to come even higher. Now with your knees fully locked externally rotate the legs inside of the hips so that your knees point up towards the ceiling. Both of your heels should be on the floor and in 1 perfectly straight line with your knees and hips. Make sure your hips are not hanging towards the front or back out of line.
In this new and corrected position slowly slide back down towards the middle split keeping the knees locked, legs externally rotated and everything in line. Like this you can be sure that you are actually stretching your middle split and that with any height difference gained you actually work towards your final destination and not just on the x-extension of your knees. Even if you would bend your knees now it would not be harmful at all as they are pointing upwards.
Over time when you get more comfortable and improve overall awareness and flexibility you can bring the upper body back down to a position parallel to the floor and internally rotate the legs again so they point towards the head.
The key in all training is working at the right level. You want to be challenged yet advanced enough so you can execute the drill with high movement quality and proper form. This comes easy in weightlifting as you can simply use a lighter weight. In calisthenics strength training this is a bit more difficult as you can not make your body lighter. Example of the push up: if you can not do a push up yet try it on your knees. Tricky but you don’t have to be a mastermind to think of good progressions.
With flexibility on the other hand things are much more difficult as we often can not think of ways to make exercises more accessible.
A great starting point is to break the goal position into separate parts. For the middle split we would have the hamstrings and connected with it the calves and glutes and of course the muscle that closes your hips, the adducteur muscle. Isolating those and stretching each separately will help you a lot. If bent knees are the only issue in your middle split then focusing on the hamstring chain can do the trick already.
Additionally you have to work on your muscle mind connection and specific coordination. Identify the muscles that need to be engaged to keep the knee locked and which need to be relaxed in order to advance as quickly as possible towards your flexibility goals.
As a last resort if you have unusually weak knees or past injuries there are a few options for you.
One possibility is to stretch your middle split whilst keeping both knees bent. Make sure that they are actually bent to exactly 90 degrees. Now with the shorter levers you will put less pressure on your hips and the stretch is different with your legs locked yet this will give you a safe shape to work with and to improve your middle split.
Additionally you can stretch on your back. Getting into the position is a bit funny at first (do me a favor. Record yourself and tag me in the video first time you try) but I promise you will get the hang of it quickly. Lay on the back with your feet touching each other pointing up towards the ceiling. Lay against the wall so that the back of your legs (hamstrings, calves) touche the wall. Now from here open your legs into a middle split. You might have seen this one before with an elastic behind the back connecting and pulling the feet down or with weights on the ankles. You can start here simply by laying and later also add the weight. Just instead of adding the weights to the ankles add the weight just before the knees to make sure you do not put any pressure on your knees whatsoever.
Last but not least if you do get somewhat low in your middle split you can also practice your middle split with pillows or yoga blocks under the knees to offer them support. This is only a valid option if your knees are actually straight but simply weak.
Now while these are possible ways of how you can continue to train your middle split right away your first priority needs to be to figure out what is going on with your knees. Go and get professional health. I know too many people who are past their teenage dream years and struggle with knee problems. You need your knees to walk, to get out of the car, to sit on a table and eat. You need your knees literally for everything and you don’t want to mess with that. Go see a good PT. Get a professional diagnosis of why your knees are weak, unstable or painful and improve from there. Take your health seriously!
Lock your knees. It is that simple. If you can not lock them you have to take a couple steps back and work an easier progression. Stretch your hamstrings and adducteurs separately and work on your muscle awareness to actively straighten the knees.
From the experience of a professional performer who depended on making gains and reaching goals his entire life in order to put food on the table for myself and my family: “Stay healthy and protect your body at all costs. No goal is more important than your health.”