Why can't I bend my knee / raise my back foot?
Tucking Your Knees at the Peak of Your Jump
Mechanism / Why It Happens
Your back foot may fail to rise because you're unconsciously doing something that works against it.
As explained in another Tip (Link), lifting your legs in the air is essentially the opposite side of lowering your chest. Now, imagine that you're late in lifting your legs and only start lowering your chest or trying to make your body compact after your entire body has begun to fall. Since your body is already descending, trying to lower your chest even further means increasing the downward speed of your chest and head. Your brain cannot tolerate this situation, so it immediately tries to support your body weight by lowering your front foot, which had already completed its upward movement. Rapidly lowering your front foot in the air creates a force that tends to extend your upper body in the opposite direction. As explained in another Tip (Link), you need to lower your chest to lift your legs, yet your chest is now rising. In this way, you unconsciously end up doing the exact opposite of what is required to lift your back foot, making it difficult to bring your back foot up.
What to Do
While your body is rising, you can lower your chest safely and effectively.
Looking back at what we've covered, the fundamental problem is that lowering your chest while your e
