This investigation is concerned with the study of the mechanical properties of the maturing rabbit medial collateral ligament. The purpose is to define accurately the pattern of change in the mechanical properties with time during maturation.

Bone- ligament-bone specimens of rabbits from one farm at 3, 6, 9 and 12 months of age were studied. A new set of clamps was designed to align the ligament with the loading axis. A new cross-sectional area ( CSA) measuring device was used to measure accurately the CSA of the mid- ligament. A modified VDA system measured the surface strain on the the ligament. The VDA system was found to be inaccurate at low strains. The collection and analysis of data was controlled by a computer with specially-written software.

The experimental results show that the pre- failure cyclic and viscoelastic properties increased rapidly from 3 to 6 months, and then levelled off thereafter. There was a rapid increase in the failure properties from 3 to 9 months before levelling off thereafter. At failure, the strain at the insertions were higher than the strain at mid-ligament.

Cyclic load relaxation was found to be higher than static load relaxation when the specimen was cycled first, then load relaxed. This viscoelastic behaviour is modelled using the quasi- linear viscoelastic theory by incorporating an elastic recovery term on unloading.