Supraspinatus tendonitis is often attributed to impingement, which is seldom mechanical in athletes. Rotator cuff tendonitis in this population may be related to subtle instability and therefore may be secondary to such factors as eccentric overload, muscle imbalance, and glenohumeral instability or labral lesions. This has led to the concept of secondary impingement, which is defined as rotator cuff impingement that occurs secondary to a functional decrease in the supraspinatus outlet space due to underlying instability of the glenohumeral joint.
Okay, I think this is what the above means. Yesterday I carried a heavy bag. (I gave my backpack to Alasdair as his school one was torn). This bag (aka the sack) I knitted once and it ressembles an African basket with i-cord shoulder straps in felted yarn I bought from the op shop. It is ergonomically hopeless (but economically sound!)Nor can you find anything in it, but that's a side issue.
Today I cannot do anything that involves a throwing motion. I think this is what the above means. I certainly can not focus on anything other than saying ouch every twenty seconds.