Kiso Tanren are exercises that aid in the strengthening and conditioning of joints and tendons. These foundation drills are important in which to maximize delivery and snap of Matsubayashi Ryu technique.
Regular Kiso Tanren are exercises in which to test one self. Good foundation drills are needed to formulate good basic exercises.
This video from 2002 shows senior members of Kodokan Taira dojo working through various stages of Kiso Tanren.