Knee joint vibroarthrography of asymptomatic subjects during loaded flexion-extension movements

Vibroarthrography (VAG) has been proposed as a diagnostic tool for knee joint disorders. The methodological aspects of VAG assessments, such as sensor placement and outcomes measures have not been thoroughly investigated. The aim of this study was to investigate the effects of sensor placement and the effect of the knee extension and flexion movements using different added loads on six parameters extracted from VAGs of asymptomatic subjects. We hypothesized non-uniform distribution of VAGs during knee movement resulting from the underlying biomechanical features. Linear mixed model statistical analysis was carried out. Interpolation maps of the parameters were created to illustrate their spatial distribution over the knee joint. All parameters were significantly related to load, movement type, and location. There were significant load x movement type and location x movement type interaction for ARV and MPF, respectively. Further, the topographical maps of the six VAG parameters differed underlining the complementary information of the six VAG outcomes. The non-uniformity of the spatial distribution, movement type, and the knee joint load dependency of the investigate parameters open for new uses of VAG for joint diagnostic purposes including activities of daily living. Visual summary of the main findings of the study. This figure shows that knee flexion-extension movement with various added external loads (0-1.25-2.5-5kg) were investigated, vibroarthrogaphic (VAG) signals from eight locations over the knee were recorded, linear and nonlinear analyses were conducted revealing non-uniformity of the spatial distribution of the VAGs.