This document provides an overview of shoulder biomechanics. It discusses the anatomy of the shoulder complex including bones, joints, ligaments and muscles. It then covers biomechanical concepts such as range of motion, forces, stability and common injuries. Problems with biomechanical analysis of the shoulder are also reviewed, such as the high degree of mobility and multiple contributions of muscles. Forces at the shoulder during activities are analyzed. The document concludes with examples of biomechanical problems involving summation of forces and moments.