In the 2008 Sprite Rising Star's Slam Dunk Contest Dwight Howard performed the "Superman" dunk. He donned a Superman outfit as Orlando Magic guard Jameer Nelson tied a cape around his shoulders. Nelson alley-ooped the basketball as Howard jumped from within the key side of the free throw circle line, caught the ball, and threw it through the rim. This dunk is somewhat controversial, as his hand was not over as well as on a vertical plane to the rim. Some insist that it should in fact be considered a dunk because the ball was thrust downward into the basket, meeting the basic definition of the dunk.
The defining characteristic of the depth jump is that the jump is preceded with the strong eccentric (negative) muscle action caused by dropping down from a raised surface, as opposed to a standard box jump where you start on the floor. This makes the depth jump a true plyometric movement, where the muscles are stretched suddenly (by the impact of the landing), producing a powerful shortening of the muscle fibers.
Though improving jumping technique may add a couple inches to an athlete's vertical jump, good landing technique is even more crucial. The landing is when almost every jumping-related injury occurs, not the jump itself. For this reason, athletes should spend a significant amount of time learning to land in a balanced position that distributes the impact of the jump equally across all joints of the lower body. This position should look almost identical to the take-off position.
Thus, dopamine and norepinephrine may have different effects on the kidney, the splanchnic region, and the pituitary axis, but the clinical implications of these differences are still uncertain. Consensus guidelines and expert recommendations suggest that either agent may be used as a first-choice vasopressor in patients with shock.6-8 However, observational studies have shown that the administration of dopamine may be associated with rates of death that are higher than those associated with the administration of norepinephrine.3,9,10 The Sepsis Occurrence in Acutely Ill Patients (SOAP) study,3 which involved 1058 patients who were in shock, showed that administration of dopamine was an independent risk factor for death in the intensive care unit (ICU). In a meta-analysis,11 only three randomized studies, with a total of just 62 patients, were identified that compared the effects of dopamine and norepinephrine in patients with septic shock. The lack of data from clinical trials in the face of growing observational evidence that norepinephrine may be associated with better outcomes called for a randomized, controlled trial. Our study was designed to evaluate whether the choice of norepinephrine over dopamine as the first-line vasopressor agent could reduce the rate of death among patients in shock.
Less helpful was my early realization that I was a two-hand dunker, in light of my inability to palm a basketball on the move. It’s common knowledge among dunkers that throwing down with two hands is typically harder than with one; the former requires a higher vertical leap. So as I flailed haplessly at the rim last spring with one hand, I felt not just discouragement but also fear. Fear that I would miss big chunks of my kids’ ninth, sixth, and first years on earth just so I could come up embarrassingly short on a senseless goal that my wife and I would later estimate consumed 15 to 20 hours a week, on top of my normal work hours. And fear that I had shared this idea with my editors way too soon.
Stand with your feet shoulder-width apart. Keeping your back straight, bend at your knees and hips as if you are attempting to sit in a chair until your thighs are parallel with the floor. Simultaneously extend your arms straight out in front of you. From this position jump up, straighten your legs and swing your arms back down to the side of your body. Repeat 25 jumping squats in a row for three sets with a 1-minute break between sets.
I gave myself ten weeks to dunk again. It wasn’t going to be easy: I figured I’d need to add five or six inches to my vertical in order to dunk a regulation basketball. I was in half-decent shape, and at six-foot-three, I had height on my side. But I had a few things other than age working against me—namely feet that had flattened over the years to canoe paddles, and an ankle injury I’d never properly rehabbed.
Dunking was banned in the NCAA from 1967 to 1976. Many people have attributed this to the dominance of the then-college phenomenon Lew Alcindor (now known as Kareem Abdul-Jabbar); the no-dunking rule is sometimes referred to as the "Lew Alcindor rule." Many others have also attributed the ban as having racial motivations, as at the time most of the prominent dunkers in college basketball were African-American, and the ban took place less than a year after a Texas Western team with an all-black starting lineup beat an all-white Kentucky team to win the national championship. Under head coach Guy Lewis, Houston (with Elvin Hayes) made considerable use of the "stuff" shot on their way to the Final Four in 1967.
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 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.