In swimming today, we saw different jumping techniques with the center of gravity in front and the center of gravity in the back. Each hair jumping technique has advantages and disadvantages. At the top level, we found that most male players use techniques with a lower center of gravity, while among elite female players, the two techniques are more evenly balanced.
With the center of gravity in front of the jump, most of the swimmer's weight is placed on the front foot, with the toes wrapped around the edge of the jumping platform. With the center of gravity in the back of the jump, the swimmer transfers most of his weight to the back foot by leaning back a few degrees.
Usually, the jump with the center of gravity is in front of the jump, allowing the swimmer to leave the jump faster with less force. Most of the propulsion with this technique comes from the front foot. Since the swimmer's center of gravity is directly above the arm, there is little push on the arm or hind foot. With a center of gravity in the rear of the jump, there are three potential thrusts: arms, back foot and front foot. Since the swimmer's center of gravity is slightly behind the front hand, by pulling the jumping platform upwards, a force vector can be generated that pulls the swimmer forward. By assigning more weight to the back foot, especially when using wedges, the back foot produces significant propulsion. The front foot is the ultimate driving force that propels the swimmer forward.
Using the tachometer technique, we see three very pronounced acceleration peaks occurring behind the center of gravity. The first peak comes from the arms, the second peak from the back foot, and the third peak from the front foot. Although the magnitude of the peak acceleration is not equal to the thrust force, it is related to this. Thus, by measuring these peaks, we can understand the contribution of these three potential sources of power to swimmers' jumping hair.
Among the elite male swimmers, the two greatest jumpers in the world are Caeleb Dressel and South Africa's Brad Tandy. Both use very similar center-of-gravity back techniques, but with some minor differences. One of these differences is how they grab the front end of the jumping platform with their arms as they are seated. Drexel bent his elbows, grabbed the front corner of the platform with his hand, and pulled upwards.
Brad kept his arms straight, locked from his shoulders, fingers and thumbs firmly wrapped around the front edge of the jumping platform. When the starting gun sounded, both swimmers were actively pulling up in front of the jump platform.