Chest Tightening

Firstly hello to anyone reading my post,

After some considerable breathing difficulties during summer 2011 I was diagnosed as being an asthmatic. I reality I think i have lived with the problem most of my life but over the last few years i have really begun to suffer

I take ventolin and fostair (steroid inhaler) which keeps my airways open an peak flow up, but my chest and ribcage PHYSICALLY SHRINKS AND TENSES UP, this destroys my biomechanics and is very uncomfortable

It is quite alarming, under 'normal circumstances' the dimension around my ribcage (not chest} is 39 inches, this shrinks to anywhere between 35 and 37 inches, it is as though my chest is clamping shut

The result is my mid-thoracic spine locks and I start to 'slouch'

Along with peak flow this is the only measurable effect i have been able to asociate with my asthma.

What on earth is happening to me and what if anything can i do, has anyone else experienced this?

The inhalers are keeping my airways open but are only doing 'half the job'