One... a rotational form of resistance, rotating on a common axis with the involved joint of the body.

Two... a direct form of resistance; resistance that is imposed upon the body part that is being worked.

Three... an automatically variable form of resistance that varies instantly as movement occurs.

Four... balanced resistance that varies in accordance with the actual requirements of the muscles in different positions.

Five... resistance that is provided in a stretched starting position; which requires a range of movement in the machine that actually exceeds the possible range of movement of the user.

Six... negative work potential

Seven... positive work potential

Eight... pre-stretching; a factor that is required during the last one or two repetitions of a set of high-intensity movements.

Nine... resistance that is provided in the finishing position of the movement, the only position of full muscular contraction.

Ten... the tenth factor may or may not be a requirement for truly proper, full range, high-intensity exercise...this being an unrestricted speed of movement.