Does eccentric weakness lead to shoulder pain or does shoulder pain lead to eccentric weakness? That’s an important question this study can’t answer. The pitchers with shoulder pain showed lower eccentric external rotation torque, but that doesn’t necessarily mean a lack of eccentric strength caused their pain. It could also work the other way. Pain can alter motor output and how the nervous system recruits muscle. In other words, the brain may essentially turn down the system as a protective response. So some of the loss in eccentric capacity we see could be the result of pain-related inhibition rather than simply a lack of strength. And most likely, the relationship isn’t that simple. Either way, it gives us something important to think about with throwing shoulders: Don’t just assess how much force an athlete can produce. Pay attention to their ability to eccentrically accept and control force especially when pain enters the equation. Pain changes performance. And sometime...