Biomechanical significance of the rotational axes in the orthotic care

Introduction: Proper rotation axes with orthotic supplies are essential for the conservative treatment of neuromuscular diseases. The exact positioning of the mechanical orthosis axes should correspond the natural axes and axes of the joints if possible.

The difficulty of a correct axis positioning is not only due to the difference of the input and multi-axis joints, but also the different characteristics or special requirement profiles of individual joints. Above all, the hip, the knee and the ankle place special demands on technology.

Methods: We put our specific system of axis determination, referring to the biomechanics of the above mentioned joints. The essential anatomical structures that are needed in order to correct determination of the rotational axes will be described. The biomechanical consequences of shifting the pivot point in the example of the hip and knee joint are shown. An objectification of the result can be administered either by a radiologist, or sonographically (radiation saving).The method should be based on clearly illustrated exemplary case studies for all discussed joints.

Results: The exact biomechanical definition of axle equitable joint positions exerts a decisive influence on the success of orthotic treatment. Especially in the application of axes correction orthosis, it is of crucial importance to correctly determine the rotational axes.

Conclusion: With the aid of imaging techniques that can correct biomechanical mode of action the results of orthotic care are very much supported objectively and qualitatively.