Has the Shoulder Joint Evolved to Throw?

March 18, 2016

PitcherAccording to a recent article in the American Journal of Orthopaedics, it’s being argued that that the human shoulder has specifically evolved for throwing. Though there are many anatomical features of our shoulder joints that remain mysterious, researchers believe that these mysteries can be better understood and possibly solved if one accepts the idea that our shoulder joints have evolved to throw.

Though Apes and Chimps can throw stones, they are unable to throw with any precision or quickness, which makes Humans unique among primates for being able to throw with accuracy and speed. This skill is a powerful asset for survival, hunting, recreational activities and is especially amazing for those of us who enjoy popular American pastimes, Baseball and Softball.Basic RGB

Pitching a ball over home plate with such precision that the batter swings and misses, or catching a fly ball in the outfield and throwing it 100 yards to get an out, is a lot more complicated than people think. In the “windup phase”, your arm stretches all the way back until it reaches maximum external rotation. It then slows down before it accelerates forward into internal rotation which is when the ball is released. Winding up generates an “elastic energy” which is then stored, transmitted and released into the ball as it’s thrown. This “elastic energy” is essential for developing the speed & accuracy needed to throw with power and distance.

Looking at the bones, tendons, ligaments and cartilage in the shoulder joint, they are structured in a way to both minimize the damage that throwing can generate and maximize the velocity and accuracy needed to launch an object. For example, your biceps, also known as the “The Popeye Muscle”, has one part that works like a spring, another like a cable and then the groove that the biceps sits in, works like a pulley. All perfectly structured to throw.

With this perspective in mind, you can see how important the shoulder joint is to sports like baseball, football & softball, to name a few. Shoulder Pain, injuries or damage may not only cause discomfort but in some cases they can end a sports career, stop someone from doing their daily job or in our newest Patient Story situation, it ended his ability to play Softball, his primary daily activity. Stay tuned over the next week when we share Mark’s video of his return to the game! In the meantime, check out these other patient testimonials.

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