Application Of The "Figure Eight" Theory to Human Movement

Abstract

Given the constraints of the human body and the goals of various movements in sport and daily life, the "figure eight" theory provides a method for observing situations and selecting the appropriate movements i.e., the prooess, used to produce an appropriate outcome. This process is a strategy for applying force and/or control without requiring precise knowledge of the magnitude of kinematic or kinetic variables. The application of force in the tennis forehand and backhand provides a useful example for our discussion. The "figure eight" pattern of clockwise movement of the right hip and counterclockwise movement of the left hip provides one option for performing the forehand and backhand strokes (Figure 1) Figure 1 - "Figure Eight" pattern The reverse of this pattern i.e., a counterclockwise movement of the right hip and a clockwise movement of the left also provides an alternative for force application in the forehand and backhand strokes (Figure 2). Figure 2 - Reverse Figure Eight pattern Knowledge of and the ability to perform these two patterns provides the player with two options for the forehand and two options for the backhand drive. Choices for using each pattern, given various ball placement situations, will be shown. To demonstrate the flexibility of the "figure eight" an example from daily life skills will also be presented.