Vertical jump
Encyclopedia
A vertical jump or vertical leap is the act of raising one's center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...

 higher in the vertical plane solely with the use of one's own muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

s; it is a measure of how high an individual or athlete can elevate off the ground (jump) from a standstill.

Types of vertical jump

The vertical jump is divided into two different types:
  • Standing Vertical Jump: This refers to a vertical jump done from a standstill with no steps being involved at all.
  • Running Vertical Jump: This refers to a vertical jump after an approach or run to help add energy to the jump in an effort to improve on the standing vertical jump.

In general, the standing vertical jump is the one that is used as an official measurement for athletes.

Where vertical jump measurements are used

Vertical jump measurements are used primarily in athletic circles both to measure performance and as something athletes brag about among themselves. The most common sports in which one's vertical jump is measured are track and field
Track and field
Track and field is a sport comprising various competitive athletic contests based around the activities of running, jumping and throwing. The name of the sport derives from the venue for the competitions: a stadium which features an oval running track surrounding a grassy area...

, basketball
Basketball
Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules...

, football
Football
Football may refer to one of a number of team sports which all involve, to varying degrees, kicking a ball with the foot to score a goal. The most popular of these sports worldwide is association football, more commonly known as just "football" or "soccer"...

, and volleyball
Volleyball
Volleyball is a team sport in which two teams of six players are separated by a net. Each team tries to score points by grounding a ball on the other team's court under organized rules.The complete rules are extensive...

, but many sports measure their players' vertical jumping ability during physical examinations. In addition, single and multiple vertical jumps are occasionally used to assess muscular strength and anaerobic power in athletes.

How to measure vertical jumps

According to Jimmy Winslow of Vermont, 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 mark off the highest point he/she can reach flat-footed (this is referred to as "standing reach"). Then, instruct the athlete to take several jumps from a standstill, marking off the highest point he/she can reach. Next, measure the distance between the two. This is the athlete's standing vertical jump and this can be monitored to track any increases in vertical jump.

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/her vertical jump based on the time in the air.

A second, more efficient and correct method is to use an infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

 laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

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 bunghloe 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.

Vertical jump as an assessment

A vertical jump of 40 in (1 m) or more is considered outstanding. Some athletes have even recorded vertical jumps over 50 in (1.3 m) which is extremely rare.

Common misconceptions about vertical jump

The most common misconception about vertical jump is that the measurement displays the athlete's ability to elevate off the ground from a run-up, contrary to from a standstill. The effect of this misconception is that many athletes will grossly inflate their vertical jumps. Also, athletes have learned to "cheat" the existing systems. The vertec can be cheated by not reaching as high on the initial measurement commonly referred to as "shrugging one's shoulders".

On the other hand, in practical terms, a running approach is often appropriately noted. E.g., in volleyball, defenders at the net waiting to put up a block against a spiker will have standing jumps, but the spiker will have a running approach.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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