in the tutorial "balance explained" we learned that an erect posture needed a longer front and a shorter back. ready to wear garments need to be altered to accommodate this posture. in figure A this is the usual alteration when the problem shows only at the top of the back. its often just the effect of the head and neck being in an erect position. figure B. is used when the extreme posture effects the entire back. the sleeves are removed, the collar is removed, except where it joins the lapel. the shoulders are taken apart and, the lining also. the entire top of the back is cut shorter see the dotted line.in some cases the dotted cutting line is angled like the line in figure A. then the whole thing must be reassembled. thats a job that takes a great deal of time. figure C. when the shoulders and upper back are fine, but from the shoulder blade on down is the problem then we just drop the back down. the arrows show the movement. the side seams are opened, and the lining as well. the dotted line on top show the new position of the back. we can see how the front is now longer than the back. the dotted line at the bottom shows that the coat hangs lower. that is then shortened to match the bottom of the front. figure D. sometimes extreme alterations, shortening from the top or dropping the back, can cause complications. we learned this, remember on "taking in a jacket sides" taking in too much on the sides caused diagonal lines of strain. the curved arrows show the strain that can occur. to release the strain we do this. the under arm side seam is opened thats the one from the armhole to the pocket. the top of the pocket is disassembled. that wedge of cloth is cut off and the top of the side body is cut off at the top to match. the under arm is re sewn and the pocket is remade. again much much time.