Knee dynamic analysis in the development of above knee prosthesis for alpine skiing
Editor: Udo Lindemann, Srinivasan V, Yong Se Kim, Sang Won Lee, John Clarkson, Gaetano Cascini
Author: Demšar, Ivan; Supej, Matej; Duhovnik, Jože
Institution: 1: University of Ljubljana, Faculty of Mechanical Engineering, Slovenia; 2: University of Ljubljana, Faculty of Sport, Slovenia
The development of biomechanical systems requires detailed knowledge of a natural system. The work includes an analysis of the natural process of the kinematics and dynamics in the knee joint in a laboratory simulation of motion through a ski turn. Measurements and analyses of the results are the foundation for the development of the prosthetic knee for ordinary two-track skiing for above the knee amputees. A dedicated testing facility was built, allowing simultaneous capturing of leg structure kinematics and surface loading rates. Changing additional vertical loads in the waist area, different conditions of performing a ski turn were simulated. Measuring the kinematics and dynamics of a control group of able-bodied skiers show that rotation in the knee joint is below 60°. Longitudinal force in the knee reaches values of up to 1.2 N/kg. Average vertical load in the knee exceeds 10 N/kg. The knee flexing/extension moment reaches values of over 1.5 Nm/kg. The presented laboratory measurements are comparable with those on ski slopes and represent the basis for the development of tailor-made prosthetic knees.