BONE STRAIN IN THE EQUINE TIBIA - AN INVIVO STRAIN-GAUGE ANALYSIS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 45  (5) , 880-884
Abstract
Rosette strain gauges were bonded to the cranial, caudal and medial surfaces of the tibia in the middiaphyseal region of 6 adult ponies. While the ponies were walking, the cranial side was subjected mainly to tension, and the caudal side, to compression. The compression strain on the caudal side was 1.5 times greater than the tension strain on the cranial side. None of these principal strains was aligned along the long axis of the bone; both deviated laterally from the long axis. On the medial surface, the principal strain deviated caudally .apprx. 40.degree. from the long axis. Analysis of the strain patterns on the 3 sides of the bone revealed that during loading of the tibia, torsion was superimposed on craniocaudal bending. The strain pattern was not affected after transection of the cranial tibial muscle, as determined by measuring with the same gauges before and after surgical interference. The contribution of the cranial tibial muscle in reducing the strain in the tibial cortex was thus very small.