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Static verus Dynamic Stretches: When to use which
Author : Jason White, Certified Athletic Therapist Category : Exercise and Fitness
The major goal of stretching, no matter the type, is to improve range of motion (ROM). Range of motion is defined as the degree of movement that can occur at a joint or a series of joints of which both static and dynamic stretching can help increase your ROM, but when should I use which?
Static stretching is most simple and commonly used type of stretching; it involves a person placing a muscle or group of muscles in a lengthened position and then maintaining that position for a variable period of time ranging from a few seconds to several minutes. By holding the position for a sustained period without movement, the stretch reflex can be bypassed.
The Stretch reflex occurs when a muscle is stretched such that the primary sensory fibres of the muscle spindles, located in the muscle belly, respond to both the velocity and the degree of stretch, and send this information to the spinal cord. Likewise, secondary sensory fibres detect and send information about the degree of stretch to the central nervous system. The passing of this information to the motor nerves activates the fibres of the muscle, causing them to contract, thereby reducing or even stopping the stretch.
Does static stretching prior to activity achieve the goals of injury prevention and performance enhancement? Research has shown that static stretching can be detrimental to performance and doesn’t necessarily lead to decreases in injury. One reason why many believe that the typical static stretching (static stretching is holding the affected muscle in a stretched position for 20-30 seconds) does not help prior to exercise is the lack of increased blood circulation. When you hold the stretch for a prolonged period, you are increasing the length of the muscle, but not the blood flow. The first thing that happens when you step on the field or go for a run is the muscles need a sudden surge of oxygen-enriched blood. Static stretching does not do this — but dynamic stretching will.
Dynamic Stretching involves progressive amplitudes and range of movement preformed in a swinging or pendulum movement and is often confused with ballistic stretching. Dynamic stretches are usually used at the beginning of a training session after a proper warm up has been done. Dynamic stretches are an active way to get the blood in the muscles and core temperature of the body elevated and in condition to perform certain exercises and movements. Dynamic stretching consists of controlled leg and arm swings that take you (gently!) to the limits of your range of motion. Ballistic stretches involve trying to force a part of the body beyond its range of motion. In dynamic stretches, there are no bounces or "jerky" movements. An example of dynamic stretching would be slow, controlled leg swings, arm swings, or torso twists
Examples of dynamic stretching include: A running may perform butt kicks, which are movements of trying to kick their buttocks with there feet, while running a distance; a tennis player would perform lunges in multi-directions and lengths prior to starting a game. This type of stretching increases your core temperature, muscle temperature, elongates the muscles, stimulates the nervous system and helps decrease the chance of injury. Dynamic stretching seems to be more advantageous to the person when perform prior to the exercises routine.
Be sure to stop when and if you feel tired. Tired muscles have less elasticity, which decreases the range of motion used in your movements. Continuing to exercise when you are tired serves only to reset the nervous control of your muscle length at the reduced range of motion used in the exercise (and will cause a loss of flexibility). Once you attain a maximal range of motion for a joint in any direction you should stop doing that movement during that workout. Tired and overworked muscles won't attain a full range of motion and the muscle's kinesthetic memory will remember the repeated shorted range of motion, which you will then have to overcome before you can make further progress.
Current research work detailed in Medicine & Science in Sport and Exercise 33(3), pp354-358 and Journal of Strength and Conditioning Research, vol 15 (1): 98-101 suggests that the use of dynamic stretches - slow controlled movements through the full range of motion - are the most appropriate exercises for warming up. By contrast, static stretches are more appropriate for the cool down at the end of the session.
A basic exercise routine would look like:
- Brief warm-up (5-10 minutes)
- Dynamic Flexibility/Stretching Routine
- Exercise Routine
- Static Stretching/Cool Down
Dynamic stretching is just one of many ways to warm up before an activity.
No matter what your goal is in training; flexibility is a major ingredient to help you have ultimate success in exercise routine, but only you can answer the question of whether stretching should be a key part of your regime.
