Giacomo Di Grassi
"Englished" by I.G. gentleman (1594)
Practical Translation by Kevin Baun (2006)

Original Text:
"The right leg should always be the strength of the right hand, and likewise the left leg of the left hand: So that if at any time if shall happen a thrust be forcibly delivered, reason would that it be accompanied with the leg : for otherwise, by means of the force and weight, which is without the perpendicular or hanging line of the body, having no prop to sustain it, a man is in danger of falling. And it is to be understood, that the pace doth naturally so much increase or diminish his motion, as the hand. Therefore we see when the right foot is behind, the hand is there also : so that who so strains himself to stand otherwise, as he offers violence unto nature, so he can never endure it : wherefore when he stands at his ward, bearing his hand wide, there also the foot helped by his strength, being placed towards that part : & when the hand is borne at low, and the right foot is before, if then he would lift his hand aloft, it is necessary that he draw back his foot : And there is so much distance from the place where the foot doth part, to align itself to the other foot, as there is from the place where the hand parts, to that place where it remains steadfast, little more or less : wherefore, presupposing the said rules to be true, he must have great care to make his pace, & move his hand at one time together : And above all, not to skip or leap, but keep one foot always firm and steadfast : and when he would move it, to do it upon some great occasion, considering the foot should chiefly agree in motion with the hand, which hand should not in any case whatsoever happen to vary from his purpose, either in striking or defending."

Practical Translation:
The lower half of the body must be able to support what the upper is doing. You should be conscious of how your hands and arms moving and where they are in relation to your feet and legs. If you do not keep the motion of the hands and feet in agreement then you are likely to become unbalanced while delivering or receiving blows. It is important to understand that the balance of each part of the body depends on each other part. Be mindful of this natural balance and take care not to let one part out pace the other. Be aware of the distance of you travel when advancing or retreating. The distance that your vertical center travels in each step should be about the same distance that the hand travels when moved from the ward to regular extension. Remember that the hand should follow the foot. For example if you are en guard with your left leg to the rear then the left hand should be left to the rear. This assists with balance, strength and timing. Failure to heed this principle during a bout creates a weakness as that person is unable to respond with strength and celerity. The placement of the feet is also a factor when considering the placement of the sword arm. When the stance is wide: the sword arm should be low and held with strength. When the stance is narrow: the sword arm should be high and threatening. The inverse is also true: the more you lower your arm the more you should open your stance and the higher you raise your arm the more you should narrow your stance. When moving the arm, or adjusting the stance, the hand and the foot should travel about the same distance. That is to say if you raise your arm 10 inches, you should withdraw your leading foot about that same distance. It is of great importance that care is taken to maintain synchronization between the pace and the hand. Above all things though it is vital to not skip or leap about. Always keep one foot firmly on the ground. When you're ready to move take great care to assure that the motion of the foot is in agreement with the intention of the hand, and the hand should never vary from it's purpose of striking or defending.

Other interesting foot work stuff. these are "Ground Plans" sometimes called 'the circle' or 'wheel'. Period fencing instructors became increasingly interested in the geomitry of motion; both foot and blade. These intrests evolved into ever more complicated patterns. the patterns below are ones that I've recreated from various period works. Why not just post the orginal prints? Well they are often drawn from perspective and with few exceptions are they the focus of the picture.