Increased Friction in Animal Joints with Duration under Load : Measurements Using Robotics

Abstract

Increased friction in animal joints with duration under compressire load was measured using a robotic system. Force control of a robotic arm was used to survey the geometry of a sliding surface. Compressive load of 10 N was added between the femoral condyle and the tibial plateau at a flat and horizontal point before friction started. Six canine stifles were used. The starting frictional coefficient was 0.006 S.D. 0.003 immediately after loading. This value increased to 0.183 S.D. 0.054 after 1800 s under load. Furthermore, the friction between the femoral condyle and the glass plate increased in a similar manner. We concluded that the ploughing effect was slight in friction occurring in animal joints.