No, seriously, it happened
1. When did the pain begin?
Yesterday immediately following a (final) set of 295lb quarter-squats.
2. What were you doing at the time? Or did the pain come on gradually over time?
See #1.
3. Where, anatomically, is the pain?
Left anterior deltoid origin point with the lateral clavicle
4. What does the pain feel like? Sharp? Dull? Aching? Stabbing? Shooting?
Relatively sharp ache but not stabbing (as in doesn't feel like a tear of some sort) with minor residual aching after initial pain.
5. Is the pain constant, or intermittent, or only on certain motions?
Pain is sharpest when shoulders are internally rotated 90 degrees (elbows flared out) and pressing downward (think dips). Same motion with elbows tucked produced about half yet still still significant pain. Also increased pain when shoulder is internally rotated, elbow is bent 90 degrees behind back, and shoulder is extended past parallel with body.
6. What motions make your pain worse?
See #5 (figured this out when standing from a desk chair with armrests at work).
7. What, if anything, makes your pain better?
Not doing #5
8. Does your pain radiate to any other part of your body?
Not yet.
9. What things could you do before, that you cannot do now because of your injury?
Unsure. Bodyweight push-ups (flexion) are no problem. No attempts yet at weight-bearing extension.
10. What is your main concern regarding the pain and its consequences?
It's bench press and bent-over row (the latter of greater concern) day today
11. Have you ever injured that part of your body before? If so, how?
Oh sure. Lots of rotator cuff issues in the past, but those were oriented more laterally and interally. This is clearly anterior and superficial.
12. Is your pain getting worse over time? And if so, how much worse over what time period?
No change since onset, which could simply be an impingement from the Olympic bar (didn't use a bar pad, shame on me).