Cardiac trabeculae are thin strips of muscle within the ventricles that can be readily excised and used to investigate contractile mechanics of cardiac muscle. Recently, the Auckland Bioengineering Institute has developed a novel cardiac myometer that simultaneously measures force, length and shape of actively contracting isolated cardiac trabeculae. Here we have developed a muscle-specific computational model based on optical coherence tomography geometric surface data that replicates passive mechanics of trabecula using a Guccione constitutive relation. We hypothesised that the muscle's surface geometry data, in addition to force-length data, would improve the fit between the model simulated mechanics and the experimental data. The trabecula