As musculoskeletal illnesses continue to increase, useful computerised muscle modelling is crucial. This paper addresses this concern by proposing a mathematical model for a dynamic 3D geometrical surface representation of muscles using a Radial Basis Function (RBF) approximation technique. The objective is to obtain a smoother surface while minimising data use, contrasting it from classical polygonal (e.g., triangular) surface mesh models or volumetric (e.g., tetrahedral) mesh models. The novel method is tested on multiple data sets, and the experiments show good results according to the introduced metrics.