The ability to work with an elastic resistance allows to use this volleyball exercise for young athletes and for high-level volleyball players too.

 


The use of elastic and a bench on which to land after the jump is decreasing by far the number of impacts to soil, then the burden on already overstretched tendon system during training session is lower.

 

https://www.youtube.com/watch?v=7bh5J2lbgMw
Moreover, the work force that can go to alternate with technical work in the field as the jump to block makes this specific exercise for volleyball.

source: preparazionefisica.org