Analysis of acceleration in the knees is very difficult due to the high sensitivity of the acceleration sensor. However this method is important for measuring the force directly. Other kinematic techniques, such as the use of a goniometer are assoaoted with a lot of procedural noise and require the calculation of acceleration by a differentialequation. Therefore we selected an accelerometer to measure acceleration of the lateral thrust. Date was integrated and accuracy checked for comparison with image analysis using a video camera. Femoro-tibial angle (FTA) and mechanical axis (MA) are indices of static analysis using X-ray image.
We compared these indices with acceleration kinetics.
Accelerography results are highly reproducble and the results of comparison with image analysis indicate that accelerography has excellent accuracy and sensitivity for measuring insole effects. All cases of medial compartmental OA knees indicated a lateral thrust pattern (LTP) and accelerography of the wedged insole effective knee showed disappearance of LTP or a decreased first peak (FP) just after heel contact. FP related to the height of the wedged insole. FP with medial wedged insole increased in proportion to height but decreased with the lateral wedged insole. There was no correlation between FTA, MA and FP.
