Lower left side of back

My wife and I deliver newspapers, last Friday she tried to lift a bundle of papers (50) from the back of our explorer to the back seat. She is 36 4'10" 105 lbs .Since that time she has been experiencing pain in the mid to lower left side of her back. She also has been finding it hard with deep breaths. The pain does move a bit to the front when she is laying on her side trying to get comfortable. She says it feels like she was sucker punched in her back. We have tried hot pads, ibuprofen, tiger balm ointment. There has been no change in her symtoms (symptoms).   I thought maybe she had pulled a muscle or bruised her ribs leaning over the back of the seat or something like that.  Any help you can give would be appreciated.

Thanks

[mike1105]

indeed it sounds like a bruised/ulled spasming muscle or perhaps even a rib that has been pulled out of place. either way, the tx is to massage and strech the involved muscles. when the musculature relaxes,(if it is a rib issue) the rib should fall back into place on its own