Re: Knee health and Aikido
Ensure you do irimi-tenkan without lateral twisting of the knee:-
I used to get knee pain, and this was in part due to the back foot swinging round too much in relation to the front foot, thus twisting the front knee. The heel of your front foot should point to the heel of your back foot - if your back foot goes past this it is likely you are twisting your knee.
Even if you've been doing irimi-tenkan for years, practise it again, really slowly: step forward and twist your foot towards you before placing it down. Your HIPS (which are ball and socket joints, unlike your knees) should be stretched by this movement. Then turn your hips and step back, ensuring that you don't step further behind than the heel of your (now) front foot. It will seem difficult at first, but you will save yourself alot of overstretching of the knee in the future, and it will also open up your hip joints considerably.