Often I meet, in real and virtual world, taijiquan practitioners or ex-practitioners complaining about knee pain.
During taijiquan practice, maintaining the correct posture of the body both in static positions and during movement stresses our lower limbs. In my mind , the right posture of the lower limbs is more important than the stance of the upper ones, as the body weight amplifies any issue on lower joints.
A simple way to check knee correct position is the alignment between the foot and the knee:
“Looking at toes, knee and the foot lay on the same line“
The image below shows Master Chen Peishan in ma-bu position; the green line represents the eye-knee-foot alignment.
![taichi palermo postura ginocchio](https://www.chentaichi.it/v1/wp-content/uploads/2019/06/ginocchio.01-1024x576.png)
First requirement: posture. The body is upright and centered, the weight is correctly distributed as the pose requires (in this case, the ma-bu position). After that, using my peripheral vision so as not to affect my posture, I check knee alignment.
Looking towards my right toe, I see what is shown in the following image (the following images are point-of-view shots)
![taichi palermo postura ginocchio](https://www.chentaichi.it/v1/wp-content/uploads/2019/06/ginocchio.02-1024x576.png)
The eye-knee-foot line crossing points are indicated using the green color. The knee is on the eye-foot diagonal without bending sideways: inside on the left of the image or outside on the right.
The same principles apply to all taijiquan poses. The following images refer to the left-side gong bu pose (the left leg is out).
Looking towards my left toe, I see what is shown in the following image
![taichi palermo postura ginocchio](https://www.chentaichi.it/v1/wp-content/uploads/2019/06/ginocchio.03-1024x576.png)
In this pose, the sideways deviation, from the right position, is even more evident.
The next image shows what I see looking at the right toe (the right leg is the back one in this pose)
![taichi palermo postura ginocchio](https://www.chentaichi.it/v1/wp-content/uploads/2019/06/ginocchio.04-1024x576.png)
Like body posture, we have to govern knee position in both static poses and while moving from one stance to another, avoiding ‘strange’ knee movements while we shift our weight / body