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. There are numerous factors that inhibit or increase joint ROM. The first includes connective tissue structure and a person’s activity level. The more active a person is the more likely they are to have better ROM than a sedentary individual In addition, age and sex are also important factors affecting ROM and flexibility, these can not be altered by training. In dealing with age, ROM and flexibility are usually decreased as people get older. When investigating sex and flexibility, typically, women are more flexible than men. It has been found that elementary school girls are more superior to boys in flexibility, and it is likely that this difference exists throughout adult life.
Flexibility and ROM are very closely related, although flexibility is shown to be a measure of a persons ROM. Flexibility is normally highly specific to the joint being evaluated. It is possible to have a high level of flexibility in one joint and limited ROM in another. Flexibility has numerous benefits such as allowing full ROM at joints, while also helping to increase performance in sports and recreational activities. The previous benefits go hand in hand with another benefit, which is the decreased risk of some types of injuries. Movements that require flexibility and joint ROM are more likely to be performed and maintained while staying injury free the more flexible a person is. For those not involved in recreational activities or sports, increased flexibility can aid in performance of their activities of daily living (ADL). In addition, in some individuals flexibility may aid in the reduction of lower back pain.
There are two major types of flexibility. The first is static flexibility followed by dynamic flexibility; while both are extremely important and beneficial, you must first know when to try to increase them. Static flexibility is the range of possible movement about a joint and its surrounding muscles during a passive movement. This type of flexibility requires no voluntary muscular activity. Dynamic flexibility is just the opposite of static in that is does require voluntary muscle actions. Dynamic flexibility is about movement and the available ROM during active movements. Even though both types of flexibility are very different they both coincide with each other to help improve performance.
Dynamic and static flexibility are improved through what is so originally named static and dynamic stretching. The intent of stretching is usually to achieve a short-term increase in the ROM at a joint or to induce muscle relaxation and therefore decrease the stiffness of the muscle-tendon system. Moving a limb to the end of its ROM and holding it in the stretched position for 15-60 seconds is termed static stretching. Depending on the comfort and fitness level of the person the stretch may need to be held for shorter or longer durations. Dynamic stretches are achieved by performing functional-based exercises, which use sport movements or traditional movement patterns that will help the client prepare the body for movements they will soon execute.
Static stretches are usually used at the end of an exercise bout. This type of stretching helps to increase flexibility and provide a nice cool down. Studies show that significant gains in range of motion can be achieved with a static-stretching program after activity. 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. Typically they are used more in athletic settings because they are very applicable to athletic performance since they closely replicate the movement requirements seen in training and competition. This does not mean that non athletic clients can not perform dynamic stretches, because they most definitely should, they just need to be varied more to fit the type of exercises they soon will perform. Both types of stretches have their certain place in a persons training program and should be used appropriately.
Some studies that have been done with athletes relating to the differences and effectiveness of static and dynamic stretches preceding activities are very significant in relation to exercise training programs. A study done by Pediatric Exercise Science involved thirteen competitive gymnasts and subjected them to drop jumps under two conditions. The first was immediately following a passive, static stretch and the other was without prior stretching. Results of the study revealed that children’s lower extremity power is reduced when the performance immediately follows passive, static stretching. Another study stated that although stretching has been found to be effective in causing an acute increase in ROM at a joint, research indicates that static stretching can also produce a significant acute decrement, of approximately 5-30%, in strength and power production. On the flip side of the previous studies, one research team shows the opposite effects. The Department of Health and Human Performance at Messiah College utilized a study to examine the effects of static and ballistic stretching on vertical jump performance and to see if whether power was altered at 15 and 30 minutes after stretching. The results indicated that there was no significant difference in vertical jump scores as a result of static or ballistic stretching, elapsed time, or initial flexibility scores. This suggests that stretching prior to competition may not negatively affect the performance of trained women.
As you can see in the research that has been done, dynamic and static flexibility both have their places in a comprehensive exercise training program. Before starting a training session make sure clients perform a warm up of some type for 3-5 minutes. This can include jogging, jump roping, or riding a bike; anything that promotes blood and oxygen circulation while also elevating musculature temperature. After this has been done a dynamic stretch/warm up should be followed. Depending on who you are training, the dynamic warm up will be different, therefore it is essential to know what type of athlete or special population you are working with and adjust the dynamic warm up accordingly. After completion of the training session to help cool the body down in conjunction with increasing flexibility and ROM a passive, static stretch should be performed emphasizing slow controlled movements at all the major joints and muscles. No matter what the goal of the client you train is; flexibility is a major ingredient to help them have ultimate success.