The most brilliant minds in the world at one point thought the Earth was the center of the universe, only to realize that they were wrong (it’s the sun by the way). So, to say that anyone is a master of the human body and how it works, it probably kidding themselves. Claiming to be a master in their field requires a certain level of confidence and a certain level of naivety.
Therefore, it is with a humble approach, I am sharing what makes sense to me (and hopefully through logical, physics, and mechanics, it’ll make sense to you too) regarding why shoulder injuries happen to people and specifically, to climbers.
The arm is a long lever arm and the shoulder joint itself (the glenohumeral joint) is the fulcrum. According to Physics 101, wherever the fulcrum is at (along the lever arm) is where the most force is being produced. In this case, each time we lift our arm, there is several times more stress occurring at the actual fulcrum point. If we do not have the strength or control to be able to lift this object with our hands, we are putting undue forces to the shoulder girdle and at some point, the system will fail, and we are left with an injury of some sort. I’m sure we have all known someone with an impingement in the shoulder, a rotator cuff injury, a bicep injury, etc.
Every joint in the body needs to have the perfect combination of mobility (the ability to move) and stability (the ability to control the movement). Across the spectrum injuries, injuries typically occur when too much uncontrolled movement is happening at a part of the body. The shoulder is the most mobile joint in the body. It has free reign to pretty much move into any position it needs to. Therefore, when the arm is in a position that is more vulnerable or weaker and then a force/load is applied to the arm, it becomes more susceptible to injuries. Again, the most force is loaded through the fulcrum. That shoulder, at that moment in space and time, might not have efficient strength and/or control of that movement, which caused a structure (ligament, tendon, bone) to give away, thus resulting in an injury.
An example that all climbers can relate to would be the awkward feeling we all have encountered while performing a gaston. A gaston, for those of you who are not versed in climbing terminology is grip when a hand is positioned with the thumb down and elbow out. Kind of like a reverse side pull. The grip maintains contact on the hold and a tension is created by pulling outward toward the elbow. During a gaston, the shoulder is in an awkward and outward position and a unique pressure is put into the shoulder joint that is typically not duplicated in any fashion of exercise outside of climbing. Therefore when put into that position, the shoulder typically feels “unsafe” or “vulnerable” and quite frankly, that is where several shoulder injuries can occur.
If your training or exercises do not mimic that position/movement and your shoulders do not have the strength/stability to sustain the force you are providing, then your shoulder will be more susceptible to having an injury. Any exercises you perform that help that position and movement will be beneficial, but there is always a good, better, best exercise to perform.
George Hwang, DPT
Vida Integrated Health
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