2. Don't lean too far forward. Once your torso has moved from slightly ahead of your hips to past your toes, your ability to breakaway has been dramatically reduced. While leaning far forward will lend itself to running forward, it is detrimental to moving to the sides or rear. Additionally, a defender ought to expect a shove from the rear from friend or foe. If your torso's center of gravity passes your toes, you will be forced forward or downward from even a slight bump from behind.
3. Don't lock your legs. Locking major joints restricts blood flow and causes all manner of problems but more to the point, it reduces the defender's ability to keep balance adjustments lower rather than higher. For instance, a target shooter firing at long distance on a windy day will notice that if the knees are locked the body will sway from the ankles. Instantly counter-balancing at the ankles is virtually impossible, so the shooter will sway from the ankles upward, pitching back and forth. However, if that shooter keeps the knees with a natural bend (not exaggerated, just not locked) movement will be lessened by keeping adjustments from the knees upward and the knees do a much better job at absorbing and countering movement than do the ankles. In fact, properly done, good knee positioning effectively moves the shooting platform from under the feet to under the hips.
No doubt the reader has already read and memorized the sublime, delightfully enchanting, and life affirming The Perfect Pistol Shot which he probably purchased at an extraordinary value on Amazon.com, and therefore knows the dangers of leaning rearward, not mastering natural point-of-aim and proper body alignment, and understands muscular, respiratory and circulatory influences. So I won't mention all that.