The procedure for constructing the model is straight forward. You place the most relevant Biomechanical Principle at the top of the model. The second Biomechanical Principle overlays the first principle wherever similar boxes exist. The remainder of the Biomechanical Principles overlay the preceding principles in a similar manner. The order of principles will be explained as the model is constructed. The completed model was shown in my post titled "The Basics 08".

Click on "read more" to learn how the model is constructed. I start with an explanation of the most relevant Biomechanical Principle for this model.

The most relevant Biomechanical principle included in this model is the

**Projectile Motion Principle**. A projectile is an object that has been projected (thrown, struck or kicked) or dropped into the air. In sport and physical activity there are three types of projectiles: (1) round projectiles (e.g., a tennis ball, a golf ball, a baseball, a softball, a basketball, a volleyball, a soccer ball, etc.), (2) non-round projectiles (e.g., a football, a discus, a javelin, a Frisbee, etc.), and (3) the human body (e.g., when it is running, high jumping, pole vaulting, playing volleyball, playing basketball, etc.).
This principle states there are three factors that determine vertical jump height and horizontal jump distance. The first factor is the jumper’s

**linear speed (s)**(i.e., how fast is the jumper moving in a straight line when he/she becomes a projectile). The greater the jumper’s linear speed when he/she becomes a projectile, the greater the vertical jump height and/or the horizontal jump distance.
The second factor is

**relative projection height (RPH)**(i.e., the height of jumper’s center of mass when he/she becomes a projectile minus the height of the jumper’s center of mass when he/she stops being a projectile). RPH does not influence vertical jump height. For horizontal jump distance, three conditions must be considered: (1) when RPH is zero, the jumper is flying over flat ground; (2) when RPH is positive, the jumper is jumping downhill and horizontal jump distance will increase when compared to a RPH of zero; and (3) when RPH is negative, the jumper is jumping uphill and horizontal jump distance will decrease when compared to a RPH of zero.
The third factor is the jumper’s

**projection angle**(i.e., the angle from horizontal that the jumper follows at the beginning of his/her flight). In order to maximize the vertical jump height, the jumper’s projection angle must be 90 degrees. For horizontal jump distance, three conditions must be considered: (1) when RPH is zero, the jumper’s projection angle must be 45 degrees; (2) when RPH is positive, the jumper is flying downhill and the jumper’s projection angle should be less than 45 degrees (the exact value depends on how large is the positive RPH; the larger the positive RPH, the smaller the projection angle); and (3) when RPH is negative, the jumper is flying uphill and the jumper’s projection angle should be greater than 45 degrees (the exact value depends on how large is the negative RPH; the larger the negative RPH, the greater the projection angle).
The combined effect of the jumper’s linear speed, the jumper’s projection angle and the RPH determines the jumper’s

**time is in the air (t)**.
Based on these Biomechanical concepts from the Projectile Motion Principle, the following can be concluded. In order to maximize vertical jump height, you must increase the jumper’s linear speed and the jumper’s projection angle must be 90 degrees. In order to maximize horizontal jump distance, you must increase the jumper’s linear speed, the jumper’s projection angle must be optimized for RPH, and RPH should be positive if possible.

A graphical representation of the Projectile Motion Principle is presented in below.

Projectile Motion Principle |

## No comments:

## Post a Comment