The back squat and jump squat are the two most commonly-used strength training exercises for increasing vertical jump height. The back squat is clearly more effective for improving maximum force, while the jump squat can be used to shift the force-velocity gradient towards a more “velocity-oriented” profile when required. In addition, the jump squat has the secondary benefit of training force production right through until the muscles are contracting at short lengths, because of its longer acceleration phase. Even so, it is unclear whether squat variations are optimal for improving vertical jump height, because the center of mass is in a different place from in the vertical jump.
“There aren’t many people in the world who can [dunk], that’s why it has this allure, I guess,” Carter told me last fall, during his first training camp with the Grizzlies. “As far as trying to do it, there are so many ways people can go about it. The approach you’re taking is the right approach. When I was younger, that’s how I started. Tennis ball, to the point that it became easy. Then a volleyball. Then a girls’ ball. Finally I took—it was like a dodgeball. I dunked that and said, ‘You know what, I’m gonna try it.’ Next thing you know. . . .” He shrugged and smiled, the gray whiskers on his jaw sinking into a dimple.
Sports scientist are able to measure these ground reaction forces with a technology called force plates. These plates record the exact forces occurring during a vertical jump (or any other movement) and allow you to see how quickly athletes can produce forces, how large these forces are, and to expose potential imbalances between the left and right leg.
The record for the most WNBA dunks belongs to Brittney Griner. As a high school senior, she dunked 52 times in 32 games and set a single-game record of seven dunks. As a standout at Baylor University, Griner became the seventh player to dunk during a women's college basketball game and the second woman to dunk twice in a single college game. In her WNBA debut on May 27, 2013, Griner dunked twice, and as of 2014, has five WNBA dunks, including the first in a playoff game (August 25, 2014).
The method described above is the most common and simplest way to measure one's vertical jump, but other more scientifically accurate methods have been devised. A pressure pad can be used to measure the time it takes for an athlete to complete a jump, and then using a kinematics equation (h = g × t2/8), the computer can calculate his or her vertical jump based on the time in the air.