If you want to do martial arts without injuring your knees, you first have to strengthen and stretch all the muscles, tendons and ligaments that collaborate in moving and stabilizing your legs. That means pretty much every muscle and connective tissue from the middle of your back to your toes. At the same time you need to open all the joints in your legs starting from hip and going all the way down to your toes. This means that you need to be able to have full rotation around all possible rotational axes in your ankle and your hip, without twisting your knee. If you cannot put the knee over your foot, then you have a problem with your ankle or your hip rotation. Do not try to horizontally rotate (twist) your knees. They are not made to twist. So what do you do if you can’t put your knee over your foot? You need to stretch your leg muscles starting with your foot, then your ankle and finishing with your psoas and hip muscles. They are the ones that are preventing the rotation of these joints, and this is why your knee can’t be positioned over your foot. Being able to position your knee over your foot is extremely important. You should not do any moving and particularly not any power walking (sudden change of direction while applying downwards twisting pressure) exercises before and you can correctly align your leg joints.
To do that you have to start with static strengthening exercises, not moving ones. Every moving exercise involves joint rotation. If your muscles are not strong enough to stabilize the joints during the rotation, your body will fall out of correct alignment and you will injure yourself. To start, look for knee rehabilitation exercises. Or Pilates exercises. They are done lying down or sitting down, and are designed to strengthen and stretch your muscles without injuring them. Once you bring your muscles up to a necessary level of strength, you can start doing standing strengthening, stretching and rotational exercises. Make sure that during practice your knee is always over your foot and never pointing inwards or outwards. Knee should also never go over the beginning of the toes.
To test if your knee stabilizers are strong enough, do this simple test.
Do the starting weight shifting exercise which is exactly the same in any internal martial arts, and is the opening movement of any internal martial arts form. Before you start take your trousers off or roll up your trouser legs. Take your shoes off. You need to be able to see your ankles and your knees. Find a full length mirror or some kind of reflective surface. You will need to be able to check your body alignment. Don’t trust your mental image of your alignment. It is probably wrong.
Stand with your legs shoulder with apart. Your feet should point straight forward with your second toes parallel to each other. Unlock your knees. This means just slightly bend them. They should not go over the middle of your foot. Can you do this? In order to do this you need to be able to also unlock and slightly rotate your hips and open up your pelvis. Do you feel any tension in your ankles knees or hips? Look down. Are your leg bones aligned with your foot? Your knees should not be pointing inward or outward. Now move your weight over your right foot. Make sure your torso is still pointing straight ahead. Your knee should be still aligned with your second toe and is not going over the middle of your foot. Also make sure that you are not sticking your right hip out and tilting your upper body to the left and forward to counter balance. Your torso should be vertical. Can you do this? Now, with your weight fully on your right leg, lift your left leg one inch off the floor. Make sure that all previous alignments are still maintained. Can you do this? Now move left foot one foot forward, so that the heel of your left foot is now aligned with the toes of your right foot. Relax your left foot and lower it down until it touches the ground. The weight should still be on your right foot. Check your alignments. They should all still be in place. Can you do this? Now lift your left foot one inch up in the air and move it back to be parallel with your right foot. Your weight should still be on your right foot. Now move the weight to the center. Repeat the same procedure with the opposite leg.
If during this exercise you lose your alignment, this means that your stabilizer muscles are not strong enough, or they are not firing correctly, or your tendons and muscles are too stiff and short to allow full rotation of your hip and ankle joints. If you can’t do this, you should not do anything else, because you will injure yourself. The injuries don’t have to be sudden rips and cracks. They can be repetitive strain injuries, like tendon micro tears, cartilage micro tears. Eventually they can cause bigger injuries or can lead to arthritis.
You can use the above exercise to strengthen your stabilizer muscles. It should be done slowly with your feeling scanning your lower body for any overly tensed muscles and in particular any dead, not activated muscles. During the whole exercise your core muscles have to be engaged at all times. Make sure your breathing is smooth and relaxed. Don’t hold your breath. Stay in every intermediate position for the duration of 3 breaths.
Good luck.
