Teaching students in Aikido, Karate and Japanese Sword can sometimes get confusing, their syllabus differs greatly but all 3 disciplines rely upon stances and good posture to achieve their aims.
For the Karate student a stance is all about the power. A better, stronger, more rooted stance adds weight and power to a strike and enables a block to receive a greater force. Locking legs, bracing knees, driving the hips and straightening the spine are all tenants to be upheld by the student of Karate. The basics follow the line of training the immovable object to better meet the unstoppable force.
Here the fundamental premise is holding ground. Your stance cannot be moved. The very ground beneath your feet cannot be taken, you own it. More importantly, the ground beneath your opponent’s feet will soon be yours too. And as for moving backwards, well that would be giving ground and that’s just not an option.
In karate, build a strong stance to frame and support your most powerful punch. Or, if you really have to, help your block withstand your opponents!