Spine and posture disorders cover large interest in rehabilitation. Quantitative functional evaluation represents the main goal in Movement/Gait analysis. However very few studies outline the behaviour of spine during Posture and Movement/Gait analysis. To overcome such limits, several years ago our group started, a project to transfer into a complete fully 3D reliable and detailed representation, different segmental biomechanical models presented in literature. As result a complete 3D parametric biomechanical skeleton model has been developed to be used in quantitative analysis. Posture and Movement/Gait analysis are performed by 3D Opto-electronic stereophotogrammetric measurements of body landmarks labelled by passive markers. Depending on different analysis purposes, the model can work at different stages of complexity. Examples on the application of such model into biomechanical and clinical fields have been presented in literature. Our group is continuously working to add new features to such model, which is now able to fully integrate data deriving from force platforms, SEMG, foot pressure maps. By means of data fusion and optimisation procedures all these inputs are used in the model to assess lower limbs internal joint forces, torques and muscular efforts. The possibility to compute the average of cyclic or repetitive tasks has been included as well. Recently we added the possibility to assess internal joint forces and torques at each spine vertebral level and to correlate these latter with all the other model's features. The aim of this study is to present the methodological aspects of such new features and their potential applicability in clinical and biomechanical fields.