What turned humans into such a force to reckon with? There are a number of usual suspects when the topic comes up: We’re bipedal; we have these big brains that allowed us to a) develop language and b) cooperate; we have these cool opposable thumbs. NPR recently ran a story about the humble yet complex human shoulder, which made its own contribution. The shoulder makes us dangerous by making it possible for us to throw things, including weapons of various kinds. In concert with our big brains, with which we can develop extensions of our throwing ability such as the atlatl, the shoulder allowed us to bring down big animals from a safer distance. This supplied useful protein and fat, which presumably helped feed that hungry big brain and made it easier for us to survive and thrive.
In his book The Trigger Point Therapy Workbook, Clair Davies describes the shoulder injury that led him to write the book and says that for a while he thought that no one really understood shoulders or how to fix them. I can certainly appreciate that; I have had a lot of problems with shoulder pain from a repetitive stress injury (I think it was using a mouse that first did me in, back before I figured out what I was doing wrong). Shoulders might rank right up there with knees in terms of being complicated and delicate, so I guess it’s good to know that they helped get us where we are today.