The rotator cuff muscles provide stability to the shoulder joint and are responsible for coordination of the fine movements of the shoulder. The rotator cuff muscles originate on the scapula (aka shoulder blade) and taper down into tendons as they attach onto the head of the humerus.
When we hear the term “rotator cuff tear,” it typically refers to a tear in the tendon rather than a tear to the muscle belly.
What do the rotator cuff tendons look like? The best way that I can describe them would be to liken them to small ropes that have been flattened down with a hammer (for some reason, a meat tenderizer comes to mind). Take these flattened ropes and give them a waxy coating. There you have it.
Just like in a typical rope, rotator cuff tendons are comprised of many individual fibers that run in parallel. Tendons have the capacity over time to “fray” just as a rope frays with time and usage. Many people who have done significant overhead activity over time (throwing, swimming, weight lifting) have rotator cuff tendons that display this “wear and tear.” A partial rotator cuff tear is, in essence, analogous to the fraying of rope.
Last week I heard an orthopedic surgeon describe a partial rotator cuff tear to a patient. He said, “If your rotator cuff is a one hundred page book, ten or twenty pages of the book are torn.”
Will the tendon still function even though it is partially torn? The answer is, generally speaking, yes. We do, however, want to be realistic in regards to activity modification. The rotator cuff tendons sit underneath the acromial shelf of the scapula. Often there will be a rubbing of the tendons up against the shelf with repetitive overhead motions.
There is also published research that notes a decreased amount of space “under the shelf” with normal aging of the shoulder. Plan accordingly as you age. Maybe those handstand push ups are not such a good idea?
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