This paper is the second in a two-part series that provides an overview of four objective methods for measuring Seat Comfort. It provides a detailed description of three of the four concepts, Electromyography (EMG), Spinal Loading, and Body Motion. Each of these methods is discussed in terms of Theory, Test Technique, and Test Data that are strictly linked to measurable biological parameters. Graphs are included to show the nature of the specific biological activity being measured and how these activities change in response to environmental stimuli acting on the human body. A comparison of the four techniques is provided. Suggestions are made to help future efforts in developing these objective measures of Seat Comfort.