In previous months we have discussed the head and neck. June was assigned the most mobile joint in the body – the shoulder.
Biology is all about tradeoffs. To achieve the flexibility that the shoulder provides, stability was sacrificed. This is why only the strongest of us can get their shoulders to do what a hip can do for a short time and walk on their hands. This is also why the shoulder is the most frequently dislocated joint. Nowhere do we see the tension between flexibility and strength play out more keenly than in the shoulder joint.
Some people try to pathologize flexibility by diagnosing themselves as hypermobile. True hypermobility is real, but rare. Hypermobility is not being flexible. Hypermobility is also not being flexible and lacking strength and coordination to control movement. Hypermobility involves moving a joint to the point of damaging tissue. Of course, anyone can be moved to the point of injury if the force is high enough – falling on your shoulder, being jerked, etc. With hypermobility, the joint is moved to the point of damage with an “everyday” amount of force. For example, individuals with chronically dislocating shoulders can move to the point of re-dislocation and injury just from holding a small weight in an awkward position, or swinging from a bar, or flinging a sheet while making a bed. Yep, I’ve seen it. And more.
Even so, hypermobility is not the end of the world. Anyone can work to find the right balance of flexibility and strength to enjoy their shoulder another day. Biology is all about tradeoffs, remember? Would we rather have shoulder injuries sometimes or have immobile, stable T-rex-like shoulders? Sure, they would never dislocate, but we would never climb a tree, or swim the freestyle, or do a tennis serve, or scratch that hard-to-reach place on your upper back.
