What The Oxford English Dictionary Doesn't Tell You About Shoes To Strengthen Calves
https://machilinwk.doodlekit.com/blog/entry/12926856/15-people-you-oughta-know-in-the-strength-shoes-industry
Jumpsoles are among the icons of the vertical jump training world. They have been around since the 90's and claim to increase your vertical dive by 5-10 inches by adding quick jerk muscle fibers in the lower leg.