The biomechanical concepts underlying total shoulder arthroplasty including differences between the anatomic total and reverse total shoulder arthroplasty (RTSA) are reviewed. The concept of lateralization and its implications on outcomes after RTSA is explained through a historical perspective. Finally, how lateralization can be achieved via different components of an RTSA construct, as well as the potential disadvantages or trade-offs that must be considered when lateralizing in reverse shoulder arthroplasty, are discussed.