Issues picked up in chest / breast area muscles

[Green Bean]

Wasn't sure whether to post this in the Tack Room or here but decided this forum would be better suited. My horse has had a treatment which has identified an issue with the muscles in the chest / breast area. I was quite surprised as other practitioners haven't looked at this area on her before. It confirmed something that hadn't penetrated as I thought it was just her being her usual self. She pulls a face if I groom 'too vigorously' in this area. It was at the end of her treatment, so treatment will continue in the area at the end of April to see if the area can be 'released'.
What I am really asking is, has anyone had experience with issues in this area, and what was the outcome of it?

 

[Equi]

Are her hind hamstrings tight at all? My boy at the start had very tight hamstrings and his chest would have been tight at the same time. Better farrier care and stretches/treatment in the hamstrings helped his chest.

 

[Goldenstar]

Google the horses thoracic sling

 

[fredflop]

I had a horse with tight pectoral muscles, caused by other issues. Massage/Bowen treatment cleared it up