The ballistic isometric method refers to pushing against an immovable resistance for a very brief period of time (one or two seconds) while trying to reach peak force output as fast as possible (basically trying to go from zero force to max force in a couple of seconds). You can't use the yielding-isometric method here as it doesn’t suit the nature of the exercise — the nature being to produce maximum isometric tension is as little time as possible.
This type of exercise is especially good to develop starting-strength and is very useful for any athlete involved in a sport where explosive starts from a static position are involved, such as a sprinter.
