thoracic stiffness

I am a competitive cyclist and training requires me to squat weight up to 2 times + my body weight. (i am 8okg.) After each gym session- i do 2 per week , I have a stiffness in the midback betwen i think T7-T8, and i constantly need to wiggle my back to get a release of the vertibra. There is usually no pain involved , just a noticable stiffness or feeling of a locking in that area of my back .Increasingly in the last year i have noticed a constant cracking in between the 2 vertibra involved, especially when i sit up straight. Does this sound like something to be concerned about and am i causing any long term damage .

Yes and yes are the simpel answers.

I would suggest (without having examined you) that you lack control of the thoracic vertebrae you describe. By loading up the weights, you are compressing those joints in particular. By "wiggling", you free those joints up but they aren't going to like it for long.

Which city are you from and perhaps i can suggest some physios that have been trained properly in the thorax to help. I can guarantee that 99% of physios don't understand the thorax properly. Otherwise just email me.

Cheers

P.S. Don't let anyone "crack" your back down there because it is NOT more mobility you need there but CONTROL.