Center of Mass

This is the "balance point" of an object. With the human body, it is somewhere behind the navel. In a sword, it is usually near, or just in front of the hilt. It is useful to note that the "balance point" of a sword is really an average of several balances. In a sword, there are three important balances to consider; lengthwise, front-to-back, and side-to-side. While the average balance point is the one that applies in most circumstances, the others will have some subtle effects on the handling characteristics of the sword.

Center of Rotation

When a mass (in this instance, a human body) is rotating, the axis about which that rotation is occurring is called the center of rotation. In the case of a sword swing, it would be a nearly-vertical line which passes through the body, entering through the head, and passing through the hips. The exact orientation of the line will vary with the technique being employed.

Florentine

In the SCA this term generally refers to the style of fighting with two broadswords, one in each hand. Less often, it refers to the style of fighting with broadsword and dagger. Its original reference is to a style of rapier and dagger fighting. However, the term is used so widely that in this paper it will be used to refer to the two-broadsword style.

Moment Arm

The distance between the center of rotation and the center of mass of the object being moved. The length is directly proportional to the force required to move the object from rest, and to the force applied when it hits.

Radius of Rotation

This is the distance between the center of rotation and the center of mass. It is the same measurement as the moment arm, but refers to distance rather than force application.