Reconsider... ER and IR with Bill Hartman | Episode #28

The podcast episode centers on reconsidering traditional understandings of external and internal rotation, arguing they occur simultaneously rather than as distinct, opposing actions. It challenges the "dead guy anatomy" concept, which bases measurements on static, straight-plane representations, and proposes that ER and IR are superimposed, like a glass being both half full and half empty. The discussion highlights how high-force activities require internal rotation while high-velocity movements depend on external rotation. Examples from Brazilian Jiu-Jitsu and throwing sports illustrate these principles. The hosts also explore how structural biases toward ER or IR influence athletic performance and injury risk, particularly in sports requiring quick changes of direction, emphasizing the importance of individualized training approaches based on foundational archetypes rather than uniform techniques.