A Spring-Loaded Pole Design for Calibration of Force Platforms

Gait analysis is an important tool in the diagnosis of movement disorders as well as analysis of prosthetic design and function 3D motion analysis systems frequently use a combination of motion capture cameras and force platforms (FP). Inverse dynamics can be applied to calculate various kinetic outcomes from the data these systems provide. In order for these outcomes to be accurate, it is essential these systems are calibrated properly in order to provide accurate raw data. This paper reports on a new spring-loaded pole used to determine and minimize the error in force and center of pressure (CoP) data. The spring-loaded pole consists of two short segments of Polyvinylchloride (PVC), a universal joint, two springs, a rubber tip and a handle. This spring-loaded pole improves previous instrumented pole designs by replacing expensive force transducers with an inexpensive spring, allowing for a quick analysis of a systems performance and calibration.