I lifted a 125 lb training dummy in a firemans carry. now lots of pain on shoulder blade & near ribs. hurts to move it and pick things up. pops a lot ?

Tricky: without an exam, I can only give general information. Most commonly these are minor tears/abrasions of muscle and tendons. Ice, rest, aspirin like drugs for 1-2 days followed by warmth and gradually increasing the amount of weight carried. Generally better in about a week. Serious tears (rotator cuff--attaches arm to shoulder) can require surgery.

Muscle spasm: Young female lifted 125# & now pain & "popping" near a "shoulder blade". Absent sharp pain & instant popping at time of lift event ligament tear unlikely. Post-lifting muscle spasm, Superior trapezius & Subscapularis, require heat, rest & massage. Spastic Levator scapulae elicits popping as tendon of this muscle is impinged by the superior scapula spine during shoulder rotation. See comments: