A failure model for ligaments

We propose a failure model for ligament which assumes that sequential uncri mping and stretching of collagen fibers is responsible for the mechanical r esponse of ligament. We further assume that the fibers rupture sequentially and in a brittle, strain-limited manner. The model was fit to stress-strai n curves obtained from medial collateral ligaments of New Zealand White rab bits from two age groups (4 and 7 months). The model indicated that collage n modulus values ranged from 300 to 680 MPa and that fiber failure strains ranged from 6 to 22%. The model provides a convenient means of describing t he elastic and failure response of ligament using four structurally based p arameters. (C) 1999 Elsevier Science Ltd. All rights reserved.