Looking back on "balance explained" we know that its controlled from the top. For erect posture we needed shorter back and longer front. But now for a stooped posture we need a longer back and a shorter front. First - the dotted lines show the front being pulled up short. This also requires the collar to be made shorter. The back may have a bit of cloth to work with very but rarely. Second - for a more serious movement we will raise the entire back. See how the back gains length at the top. the heavy dotted line shows how the bottom of the back no longer matches the front. This means the front must be shortened to make it match. That's because there is seldom enough cloth at the bottom of the back to make up the difference. The raised back may be used alone or in conjunction with again the collar must be shortened here too. Third - this is the same alteration except for the shoulder. It depends on how the fitter sees the customer.