welcome to hcm.
fluttering over the mentioned area may be due to various reasons.
our ribs are made up of cartilage
the junction between them is called costochondral junction.
inflammation over that area is called costochondritis
its a common cause.
its manageable to treatment.
sometimes may give rise to these symptoms over that area.
unnoticed trauma may be the cause.
milder forms of post herpetic nuralgia may cause it.
to diagnosis it need a complete examination and investigation.
so please consult your doctor.