Other computer models include the biomedical, biomechanical, and digital human models such as the 3D Static Strength Prediction Program (3DSSPP) (Univ. of Michigan 2003), which offers both postural, static, and dynamic biomechanical load analysis functionalities. The 3DSSPP/AutoCAD PC model for proactive ergonomic analysis of the biomechanical risk for injury is based on the proposed workplace design (Feyen et al. 2000) and couples the 3DSSPP and AutoCAD interfaces. Dickerson et al. (2007) presents a mathematical musculoskeletal shoulder model, which includes kinematic and kinetic effects, population scalability, geometric realism, an empirical glenohumeral constraint, and integration with digital ergonomic analysis software tools.