PLYOMETRIC JUMP

Plyometric jump and strength testing

[Name of the Institute]

CHAPTER 2: LITERATURE REVIEW

Biomechanics of vertical jump

To maximize the vertical jump, the principle of training specificity suggests that people should be getting out and doing some jumping, i.e. plyometrics. Unfortunately, to get maximum results isn't as simple as just going to the nearest park and jumping up and down. The act of jumping is very taxing on one's joints, muscles and central nervous system and as such, people need to carefully plan and monitor this type of training accordingly (Hewett, 2006).

Unfortunately many trainers and coaches haven't fully understood the impact plyometrics can have on an athlete and as a result this type of training has gathered a bad reputation. Plyometrics provides the training stimulus for a number of vertical jump related benefits including:

The training of the CNS to send the required signals to the muscles to ensure they contract more explosively

The development of the muscles directly involved with vertical jumping

Development of the type II fast twitch muscle fibers associated with vertical jumping

The improved ability to transfer eccentric, or downward force, back into an upward or concentric movement

Any exercise that involves some sort of prior loading can technically be called a plyometric activity. Things like sprinting where each stride is taken one step after another have a plyometric element to it. Movements such as jumping up and down on the spot, or skipping, also have plyometric elements to them.

Biomechanics of back squat

The squat jump is a body weight exercise, where people jump straight up and fully extend their body in the air. This exercise helps people increase their vertical leap. They do provide moderate stress to the joints, so they should be done with caution if one has joint problems. Otherwise, squat jumps will work the quads, calves and abs, as well as test people's ability to land softly and with balance.

Although it is not clear whether VJ ability is directly related to success in soccer games, it is still important to enhance the VJ ability of soccer players, because it is an integral element of the key basic fundamentals of the game (e.g., in attacking and blocking). Explosive leg muscle power is an important part of increasing VJ performance, and a recent meta-analysis suggested that conditioning programs based on plyometric training can increase VJ performance by 4.7-8.7%, depending on the testing protocol. However, most studies reviewed used non-athletic subjects, and therefore it is important to understand whether this type of training can increase VJ performance in highly skilled players who may already be proficient at leaping.

Ballistic Training

Ballistic training usually refers to strength training performed explosively (e.g., power lifts). Plyometric training typically refers to exercises that involve quick movements using a pre-stretch movement or countermovement that involves the stretch-shortening cycle (e.g., drop jumps). In the following studies the terms ballistic training and plyometric training are used interchangeably and relate to training developed to increase muscular power (Wilson, 2006).

One study examined the effects of ballistic resistance training on VJ performance in NCAA Division I male ...