Influence of intersegmental contact on tibial contact forces during high knee flexion movements

High knee flexion postures (>120º) result in intersegmental contact of the lower limb. The purpose of this study was to quantify the effect of including 3D intersegmental contact on proximal tibia contact force estimations. Sixteen participants performed six high knee flexion postures while kinematics of the lower limb were recorded synchronously with intersegmental pressure and ground reaction forces. These data were used as inputs to a 3D musculoskeletal static optimization model of the lower limb to estimate proximal tibia contact forces. Including intersegmental contact as additional external forces in the model resulted in a significant root mean squared difference up to 0.42 BW in posterior shear and up to 0.08 BW in lateral shear but had no effect on tibial compression. These findings suggest that the estimation of shear forces during high knee flexion postures require intersegmental contact parameters for accurate representation.