The study looked at how rocks and coal move in steep coal seams when using a specific mining method. By analyzing a mine's working face, researchers found that as the angle of the seam and the mining method changed, the rocks and coal above the mine moved differently. The vertical displacement of rocks and coal increased with steeper angles and more mining. The area where the ground was most affected by mining got smaller as more coal was extracted. This means that how the ground moves when mining coal at an angle is different from mining coal horizontally.