Hanging high line in 23D during a power move, taking twist out of cable which jerked shoulder when it straightened. Felt pop in shoulder, missed no time until 5/18/14 injured back at home, 6/2/14 went to Dr. for shoulder, given preventative work restrictions (no use of left arm until MRI). Released from back injury on 6/13/14 and started missing for shoulder sprain/strain.