Change: The centering point is between the knees right at the level of the femoropatellar joint. Then, place the detector onto their lap and have them hold on to it at the top with both hands. Tip: Have them slighylyslightly tilt it forward, depending on   View changes from previous version. (Word count: 197)

Change: There were only format changes (bold, italics, etc.) in this version. See this version for details. (Word count: 190)