Since the magnitude of the effect derived from observational studies can be misleading, we opted for a sequential trial design with two-sided alternatives20; the trial design called for analyses to be performed after inclusion of the first 50 and 100 patients, and then after inclusion of each additional 100 patients, and allowed for the discontinuation of the trial according to the following predefined boundaries: superiority of norepinephrine over dopamine, superiority of dopamine over norepinephrine, or no difference between the two. An independent statistician who is also a physician monitored the efficacy analyses and the adverse events; on October 6, 2007, after analysis of the outcome in the first 1600 patients showed that one of the three predefined boundaries had been crossed, the statistician advised that the trial be stopped.
The player approaches the basket and leaps as they would for a generic dunk. Instead of simply dunking the ball with one or two hands, the player allows their forearm(s) to pass through the basket, hooking their elbow pit on the rim before hanging for a short period of time. Although the dunk was introduced by Vince Carter in the 2000 NBA Slam Dunk contest, Kobe Bryant was filmed performing the dunk two years earlier at an exhibition in the Philippines. Colloquially, the dunk has a variety of names including 'honey dip', 'cookie jar', and 'elbow hook'.
I went through this progression, too. I went from touching the middle of the net at 12 years old, to dunking a basketball at 14 years old, to doing serious acrobatic 360-degree dunks at 17 years old. In college, my personal record for the vertical leap was 40 inches. At my peak, I was able to touch the top of the square on a regulation backboard, about 11.5 feet from the ground. Even now, in my thirties, I can dunk a basketball while standing underneath the basket—no run up required. I owe it all to the power of the vertical jump.
In the tradition of New Year’s resolutions and the like, you can give yourself a year. I certainly didn’t want to give myself more than a year, because after a year I knew I would grow tired of it, and my body would start to get quite unhappy with me. But I would recommend to someone that they give it a go for at least six months. It’s also a way of just getting yourself in fantastic shape. I mean, trying to dunk a basketball in itself is awesome. It’s really great to be able to dunk a basketball, to get yourself higher up than you thought possible. But the process of getting yourself in that kind of position is itself rewarding.
Rope skipping is also a very basic form of a type of exercise called plyometrics. Plyometric exercises involve repetitive explosive movements, such as jumping up and down or catching and throwing a medicine ball. The idea is to execute the movement with as little downtime as possible between repetitions. This, in effect, trains muscles to be powerful and explosive, and utilize the kinetic energy inherent in athletic movements in the most efficient way.
A second, more efficient and correct method is to use an infrared laser placed at ground level. When an athlete jumps and breaks the plane of the laser with his/her hand, the height at which this occurs is measured. Devices based on United States Patent 5031903, "A vertical jump testing device comprising a plurality of vertically arranged measuring elements each pivotally mounted..." are also common. These devices are used at the highest levels of collegiate and professional performance testing. They are composed of several (roughly 70) 14-inch prongs placed 0.5 inches apart vertically. An athlete will then leap vertically (no running start or step) and make contact with the retractable prongs to mark their leaping ability. This device is used each year at the NFL scouting combine.