The force-velocity relationship during muscle shortening occurs because the number of simultaneously attached crossbridges between the myofilaments inside the working muscle fibers determine the amount of force that a fiber can produce. The number of attached crossbridges at any one time is dependent upon the fiber shortening velocity, because the detachment rate of the crossbridges at the end of their working stroke is higher at faster shortening speeds.
after a certain age dunking becomes quite difficult to gain during the prime years 12 to 21 your body is still growing so it is easier to gain to muscle and muscle fiber to be able to dunk if you are quite short below 6ft it requires great effort to get the height to dunk the only exercises i suggest are one footed Calf Raises you can find how to do them on you tube and squats i was recommended these exercises by the Glasgow rocks coach and player Sterling Davis hope that helps i am 6ft myself and learning to dunk has been a long road and still going because i am only grabbing the rim now any more questions feel no fear to send me an email
To perform two-foot dunks, jumpers bend their knees very deeply and spend a lot more time on the ground loading the jump. This increased time during takeoff is useful because it allows the athlete to transfer force into the ground thereby improving height. Using this approach makes it more difficult to transform speed into jump height making a fast approach far less useful than in one-foot jumping.
I cannot honestly say that the program absolutely works since I have yet to execute it. However, I believe that the principles and exercises absolutely work. They are honed into a system by Mr. Grover and Attack Athletics. I believe Mr. Grover to be at the top in athletic training. His list of clients and their success speaks for itself. As far as the book goes...it looks like it was written in the stone ages! But once you get past its appearance and the stars of yesteryear that appear in the book...it has quality and value. Although I believe it to be somewhat overpriced (what isn't these days???), it can help an athlete get to the next level in sports performance! Do it!
The simplest method to measure an athlete's vertical jump is to get the athlete to reach up against a flat wall, with a flat surface under his/her feet (such as a gym floor or concrete) and record the highest point he/she can reach flat-footed (the height of this point from the ground is referred to as "standing reach"); fingertips powdered with chalk can facilitate the determination of points touched on the wall. The athlete then makes an effort to jump up with the goal of touching the highest point on the wall that he or she can reach; the athlete can perform these jumps as many times as needed. The height of the highest point the athlete touches is recorded. The difference between this height and the standing reach is the athlete's vertical jump.