In order to develop flexibility, one of the following three groups of methods may be employed:
1. the active method, comprised of: a. static method; b. ballistic method
2. the passive, and
3. the combined method, or the proprioceptive neuro-muscular facilitation (PNF) (developed by Kabat in 1958).
Before briefly exploring each method, it is rather important to mention that there exists some contradiction regarding which method is more efficient. Many coaches and athletes prefer the static method for the fear that the ballistic one may lead to muscle pull. Although PNF has some limitations in its application, that is, it is applicable only to the hip and shoulder joints, this method is often preferred. However, several authors (Zatzyorski, 1980, Mitra and Mogos, 1980, Pcchtl, 1982) viewed both the active and the passive methods as being equally effective. Similarly, comparative studies (Norman, 1973) between the three groups of methods concluded that there is no difference between their effectiveness.
1. THE ACTIVE method is a technique whereby maximum flexibility of a joint is achieved exclusively through an individual's muscular activation. This method refers to both the extent of which the agonistic muscles flex as well as the relaxation and yielding to such a force by the antagonistic muscles. When using the static method two segments of a limb are flexed to the utmost point of flexibility, holding this position for 6-12 seconds. The ballistic method is performed through active swings of one segment of a limb, which is mobile, against another limb which is held still.
2. THE PASSIVE method achieves maximum flexibility through the assistance of a partner, or by employing a weight In the first case, a partner holds or presses a limb towards its maximum point of flexibility, without the subject's active involvement. This method is applicable for the following joints: ankle, hips, vertebral column, shoulders, and wrist The use of weights (barbells, dumbbells) is recommended for the improvement of ankle, knee, and shoulder flexibility. It is not suggested for the hips or vertebral column since the weight may exceed one's pain tolerance, or may press two segments of a joint to bend beyond its limits thus resulting in eventual muscle pulls In any case the load of weight has to be low, carefully applied, and very progressively increased. Such training must always be done under close supervision.
3. THE COMBINED method (PNF) requires the limb to be actively flexed to the joint's limits, then execute a maximum isometric contraction against the resistance of a partner The athlete then attempts to lift the limb voluntarily to a more acute angle which is beyond previous limits. Once again, the same routine is performed: the athlete performs a strong isometric contraction against the resistance provided by a partner. The isometric contraction may be performed for 46 seconds with as many repetitions as the athlete can physically tolerate and that is methodologically necessary.
The Methodology of Developing FlexibilityThe area of the methodology of training refers to two types of flexibility: general and specific. General flexibility refers to the idea that each athlete has to have a good mobility of all bodily joints, irrespective of specific requirements of a sport or event Such flexibility is a requirement in training, and it assists the athlete to undertake various training tasks and perform substantial unspecific exercises, or elements from related sports. On the other hand, specific flexibility implies the quality which is sport or joint specific (i.e., specific flexibility of a hurdler differs drastically from that of a butterfly swimmer).
Since the development of flexibility is more easily achieved at a younger age, it has to be pan of the training program of each young athlete, irrespective of sport specialization. If a desired degree of flexibility is achieved, it does not mean that flexibility training should be neglected. On the contrary, from this point on, flexibility programs must have the objective of maintaining the achieved level. Flexibility exercises have to be incorporated in the warm-up part of a training lesson. As already indicated, flexibility exercises have to be preceded by a general warm-up (jogging and calisthenics) of at least 10 minutes. The selection of exercises and their complexity and difficulty has to be related to the athlete's level of preparation and toe specifics of the sport. Each selected exercise has to be performed in 3-6 sets of 10-15 repetitions (or up to a maximum of 80-120 repetitions per lesson), while during the rest interval relaxation exercises have to be considered (shake the group of muscles that have performed, or execute a light and short massage). Throughout performance the amplitude of an exercise has to be increased progressively and carefully. At first exercises are performed with an amplitude which does not challenge the athlete, increasing it then progressively up to one's limits. From this point on, each repetition should aim to reach this superior limit, and even to further it.
For the ballistic method there is a high variety of exercises: flexions, extensions, and swinging. As suggested by Bompa et at (1981) flexibility may be achieved by employing free exercises, medicine balls, stall bars, and benches. The use of medicine balls (i.e., flex the hips while holding the ball with arms extended) increases the leverage of a limb. As well, it accentuates the momentum, which results in a more effective development of flexibility.
For both the static and PNF methods the athlete tries to take the position of the joints so that the sought flexibility will be enhanced. Then the performer statically maintains the position for 6-12 seconds (6-10 sets) for a maximum total of 100-120 seconds per training lesson for the chosen joints. Such a time requirement may be built up in a progressive manner over a period of time (10-18 months). Throughout the performance of static flexibility the performer should attempt to relax the antagonistic muscles so that they will yield to the pull of the agonists, thus reaching a more acute angle between two limbs.
As far as the periodization of flexibility is concerned, most of it has to be achieved during the preparatory phase. The competitive phase will be regarded as a maintenance period, when the energy and strain placed upon muscle groups will be directed towards specific training. However, in either case, flexibility has to be part of an everyday training program and should be performed towards the end of the warm up. Best results were attained when flexibility was trained twice a day (Ozolin, 1971). Even athletes performing 46 training lessons per week still may develop flexibility during early morning training, thus ensuring an adequate flexibility