Ballistic stretching involves bouncing movements done in order to increase joint range of motion, but also to increase tendon elasticity. Tendons join muscle to bone and tendon stiffness can increase the likelihood of injury. Ballistic stretching, unlike static stretching, has been shown to increase tendon elasticity making tendon rupture less likely. This type of stretching also increases the flexibility of muscles at a greater rate that static stretching.

However, ballistic stretching is not linked with improved performance other than those improvements that come with increases in range of motion. This type of stretching may help to reduce tendon rupture, and therefore, look after the athlete’s wellbeing, but it has not been shown to improve performance. It is often done in sports requiring eccentric contractions followed by concentric contractions as ballistic stretching best replicates this movement. Such sports include: basketball, high-jump, long-jump, sprinting, volleyball etc.

Furthermore, this type of stretching can be dangerous so supervision is recommended. Ballistic stretching seeks to move stretch the joint beyond its normal range of motion. It seeks to move beyond the stretch reflex (which protects muscles from tearing when stretched) for a further stretch of the muscle. However, this can result in muscle tears, whether small or large, muscle tears will decrease performance, and may put the athlete out of competition due to injury. For it to be performed safely jerky movements should be avoided.

Generally ballistic stretching is not recommended for the everyday person looking to get fit or healthy. Although it has better results at increasing flexibility, it can be dangerous if not performed properly and is usually reserved for elite athletes.

Further reading for ballistic stretching

http://www.stretching-exercises-guide.com/ballistic-stretching.html

http://www.healthline.com/health/ballistic-stretching-it-safe#3