DR check why the vertical bucky stand height should be adjusted

Why should the height of the vertical bucky stand be adjusted for DR inspection? That is, why should the bucky stand height be adjusted for DR inspection? When shooting, aim at the position of the lungs.
Let me briefly introduce our company’s simplest and most cost-effective vertical bucky stand:
Purpose: Suitable for radiographic inspection of the human body’s head, chest, abdomen, pelvis and other parts;
Function: This device is composed of a column, a sliding frame, and a film clip, which can be adapted to ordinary X-ray glue of various sizes
Film cassettes, CR IP boards and flat-panel detectors with (without) wires;
If you are interested in our vertical bucky stand products, please contact our customer service.