by performing a row on a hyperextension machine, you avoid the lats being stretched so they have more capability to initiate and contract, meanwhile you are working on your spine extension muscles(paraspinal muscle group) and deep back muscles(transversospinalis muscle group) as well. when performing an exercise, one must be aware of how the whole body is positioned and not only the parts that are moving. normal back rows are great for creating mass and strength on your back, but there are other options that can challenge you in a different way.