Abstract

Biewener, A. and Full, R.J. 1992. Force platform and kinematic analysis. In Biomechanics: Structures and Systems A Practical Approach. (ed. A. Biewener). IRL at Oxford University Press. New York. pp 45-73.

A growing crisis in organismal biology is the lack of use by other investigators of comparative biomechanics when it is essential to the problem at hand. We felt this problem is in large part due to the technical nature of the field. We composed this chapter to strip away some of the complexity in both the equipment and theory used. The book is aimed at knowledgeable investigators and intimidated graduate students who may not otherwise tackle their problem with a rigorous quantitative approach when one is necessary. I focused on kinematic analysis. Kinematics is the description of the motion of rigid bodies independent of the forces that generate their movement. This involves: 1. coordinate system set-up. How to define the problem at and select an approach for data acquisition and analysis; 2. image acquisition which includes image sampling rate and video camera selection and operation, calibrations, lighting and contrast problems; 3. data analysis by computer frame grabbing, 2D analysis, 3D analysis by direct linear transformation, and noise reduction by use of Chebyshev least squares polynomial curve fitting of displacement data followed by polynomial differentiation, second order finite difference methods, spline function curve fitting, and digital filtering followed by finite difference techniques.