Muskuloskeletale Belastungen im Schafshinterlauf: Mechanische Rahmenbedingungen der Heilung

Abstract

Although the sheep is a standard model for the analysis of biological healing processes after surgical intervention at the knee and shank, the in vivo tibio-femoral joint contact forces and the resulting musculoskeletal loading conditions have yet to be studied in detail.The three-dimensional kinematics of three Merino-mix sheep right hind limbs were recorded using reflective markers that were attached to Schanz’ screws, firmly anchored in the bone. This motion data was used together with the simultaneously measured external loading (ground reaction forces) to calculate the muscle and joint contact forces, as well as the internal loads within the bones. Whilst the motion mainly occurred in the sagittal plane, significant out of plane motion was observed, especially at the hip and knee joint (ab/adduction hip: 13°, knee: 10°; internal/external rotation hip: 12°, knee: 14°). The axial component of the tibio-femoral contact force was 2.1 times body weight (BW). The medio-lateral and anterior-posterior shear forces amounted to only 0.7 times BW. The loading in the diaphysis of the tibia under physiological musculoskeletal conditions was mainly axial compression (0.89 BW) together with only small shear forces (0.15 BW). The results of the musculoskeletal analyses presented here add to the understanding of the mechanical loading conditions in sheep. This expanded knowledge aids in the interpretation