Vertical jump

A vertical jump or vertical leap is the act of raising one's center of gravity higher in the vertical plane solely with the use of one's own muscles; 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: In general, the standing vertical jump is the one that is used as an official measurement for athletes.
 * 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.

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, basketball, football, and volleyball, 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
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 laser 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 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 or more is considered outstanding. Some athletes have even recorded vertical jumps over 50 in which are extremely rare.

Vertical jump and power output
Vertical jumps are used to both train and test for power output in athletes. Plyometrics are particularly effective in training for power output, and include vertical jumps of different types in their protocol. In one recent study, training with plyometrics (which included continuous vertical jumps) was shown to increase vertical jump performance to similar degrees in combination with very different resistance training protocols, indicating that the plyometric jumping contributed to the increased jump height moreso than resistance training. Research into plyometric jumps found vertical jumps to be among the highest in terms of muscle recruitment (as measured my electromyography), power output, and ground reaction force produced.

Fatigue has been researched in athletes for its effect on vertical jump performance, and found to decrease it in basketball players, tennis players, cyclists, rugby players, and healthy adults of both genders.

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.