Dynamic flexibility is generally defined based on a person's range of motion during movements, particularly during fast-paced movements. This is contrasted to static flexibility, which has more to do with a person’s ability to hold a stationary stretch. There are special dynamic stretching exercises designed to promote dynamic flexibility, and this approach to stretching has become popular in certain sports. The main reason for its popularity is a belief that static flexibility might hamper muscle performance, while dynamic stretching can offer the same benefits without the potential downsides.
When training for dynamic flexibility, athletes will generally focus on exercises, which take the muscles to their flex limit during a motion. For example, the athlete may kick his feet upward in a controlled motion to flex the musculature. Over time, these exercises will generally increase the height at which the athlete is able to kick.
This exercise approach is generally very similar to an older method of stretching called ballistic stretching, but there are a few differences. Ballistic stretching also promoted dynamic flexibility, but it had a tendency to cause injuries. The primary difference was in the speed and aggressiveness of the motions used. Ballistic stretching used more forceful motions, and there wasn’t as much care taken to avoid injuries. With dynamic stretching, the motions are generally more controlled and gentle, which allows for a more gradual stretch.
The other common approach to stretching that athletes use is called static stretching. This involves stretching the muscle to its limit and then holding the stretch for a length of time. Some experts think that this might hinder the elasticity of muscles and thereby decrease performance in strength-based activities. Many experts also believe that static stretching might help avoid injuries, but research has generally shown that it isn’t very effective for that either. There is also some research that suggests the performance problems of static stretching could be mitigated by holding the stretches for a shorter length of time.
Exercises to promote dynamic flexibility have become relatively common in athletics competitions, but are generally not as popular for medical rehabilitation. Some of these exercises require too much athletic ability and rapid movement, while injured people may need more gentle exercises that can help restore their range of motion. There are some experts that believe a mix of static and dynamic flexibility exercises could be useful for muscle rehabilitation, but it is still debated.