Working out Articles Archived: Flexibility

[Mop]

Not only will stretching feel great just about anytime, but it helps the body in many ways, including but not limited too;

1. Strength gains
2. improved posture
3. Improved blood flow
4. injury prevention.

the list goes on and on - thus I figured Starting off this week with Stretching as the topic of the week for working out, as it is a highly looked over with in the gym, but it's usefulness is as important as those crunches and bicep curls.

Next weeks Topic, I will be covering balance - this is the second most important thing to a strong foundation. With out Balance, how can you jump up, grab a drink, get back to your chair before the next mob is inc.

[Mop]

A stretching period, in conjunction with a warm-up, has long been an accepted method of preparing an athletes' musculoskeletal system for physical activity (Siatras et al, 2003). Stretching is often prescribed for rehabilitation, injury-prevention, imbalance-correction, and to improve athletic performance (Knight et al, 2001). Yet despite its' popularity and prevalence, there is limited scientific knowledge regarding the mechanisms and effects of stretching, on flexibility in general and on human musculotendinous units in particular (Kubo et al, 2002; Magnusson et al, 1996).

Flexibility is considered to be one of the key functional elements for complicated coordinated movement. The skeletal muscles are primarily required for the generation, dissipation, and recuperation of mechanical energy (Reviewed in Hein et al, 1998). The neuromusculoskeletal system's integrity is associated with the length, stiffness and adaptability of each individual muscle in the kinetic chain. Inadequacies in any of these areas may lead to other muscles becoming involved in movements to a greater or lesser extent than would normally be required, leading to muscular imbalances, pain, or even injury.



According to Armiger (2000), "...flexibility is an integral part of any training program and is essential in the pursuit of optimum performance, as well as injury prevention and rehabilitation." The suggested reasoning for this, is that adequate flexibility permits the required joint range of motion (ROM) during activity, in addition to injury prevention should a limb be subjected to greater than normal range. By comparison, limited flexibility may lead to muscular or joint compensations (as referred to above), direct injury within the musculotendinous unit (Armiger, 2000), or sub-optimal muscular performance (Harvey et al, 2002; Carter et al, 2000).



A loss of extensibility in soft tissues may lead to restricted range of motion of a joint. This loss of extensibility may be the result of either microtrauma or simply inadequate flexibility. Stretch interventions are therefore recommended, to both competitive and recreational athletes, as a means of increasing muscle extensibility and joint ROM (Harvey et al, 2002, Kubo et al, 2002). Stretching exercises can be self-administered or applied manually by therapists or exercise professionals. Interventions applied in this manner would typically consist of developing a stretch over a period of up to a few minutes each. Alternatively, musculotendinous units can be stretched for prolonged periods of time (up to 24 hours per day) with orthoses, casts, splints, or other similar means (Harvey et al, 2002).



To date, despite the existence of a number of articles in the scientific literature, there are few high quality papers showing consistent methodologies and results. This lack of consistency is then compounded by a number of studies with similar methodologies that are assessing for different intervention outcomes. The result is that the mechanisms for both acute and chronic changes in joint range of motion, the efficacy of stretching for injury prevention and sports performance, remain to be clarified (Harvey et al, 2002; Kubo et al, 2002; Chan et al, 2001; Carter et al, 2000; Magusson et al, 1996).



Static Flexibility



There are two basic types of flexibility that concern the exercise professional. The first type is static flexibility, which refers to the angle that a limb can be moved to at each joint, and is often measured in degrees for a particular joint and limb (Blum et al, 2000). The second type is dynamic flexibility, which refers to the ease to which a limb moves through the joint's range of motion, and angles can measured as muscular force is generated or by using the damped oscillation technique (Blum et al, 2000). Due to the ease and accuracy of measuring static flexibility it is this type which is referred to most often in the scientific literature.



Static stretching of muscles is often incorporated into both warm-up and cool-down periods of exercise sessions. However, commonly accepted protocols for the application of stretching techniques are still lacking (Chan et al, 2001). This is also true with regards to stretching for rehabilitation, injury rehabilitation and postural correction. In short, there is little scientifically based evidence for the correct application of stretching techniques for any outcome. In particular, there is no real consensus as to the best stretching exercises, the optimal frequency, number of sets and repetitions, duration of stretches held, or number of stretches per muscle or joint. Furthermore, outcomes of stretching techniques are often difficult to qualify due to confusion with joint or ligamentous laxity, either of which may be the precursor to or result of injury (Blum et al, 2000). If studies into flexibility training only consider muscle length, then, like the finger pointing to the moon and missing the beauty of the sky, the exercise scientist has missed all the connective tissues, nerve fibres, muscle spindles, and joint complexes that should be involved.



Taking this point further, if someone has used stretching to lengthen a muscle, surely this will affect proprioception? There are many purported benefits and costs of stretching prior to exercise. If someone has an area of tightness within a muscle, or a muscular imbalance, then they have an increased susceptibility to exercise-induced injury. Stretching could be effectively used to release the tightness in the muscle and return any comparatively shortened muscles to a near normal length. It would not be appropriate to begin exercise immediately following a stretching session as the body's proprioception will have been affected. Proprioception could be restored, or 'retrained', following an effective mobility phase lasting a minimum of ten minutes. This mobility phase might include a walking and light jogging period on level ground prior to a running session. For a resistance training session, the mobility phase might include exercising with light weights, across similar planes of motion to those to be included in the resistance programme (Middlesworth, 2002; Armiger, 2000; Blum et al, 2000; Magnusson et al, 1996).



Different techniques to improve static flexibility range from single set static stretching to multiple set hold-relax techniques (including proprioceptive neuromuscular facilitation (PNF)). Static stretching typically involves moving a limb to the biting point of the shortest muscle involved, and holding the limb in position for a period of at least 15 second. A hold-relax technique could then be a repeat of the static stretch, incorporating a short rest for as many repetitions as required, as dictated by the client or exercise specialist. One representative study by Gribble et al (1999), found that both static stretch and hold-relax techniques were equally effective in increasing hip-flexion ROM over a six week period. In this study, the static stretch was held for a single 30 second period, whilst the hold-relax method consisted of an eight second hold followed by a contraction of the agonist muscle for seven seconds, a five second rest, and then a ten second repeat of the static stretch at the new biting point (Gribble et al, 1999).



The suggestion that this study was representative of the scientific literature on flexibility, highlights the vast number of variables involved in such a study. In the study by Gribble et al (1999), both techniques were equally effective, although many practitioners would argue that the biting point of the muscle increases more in a hold-relax stretch. The reason may be due to a less than optimal progression of the stretch, the short time periods involved in the hold-relax technique in this study, or a combination of factors. To properly test effectiveness of stretches, the different techniques should probably be held for a longer duration. Liken flexibility training to resistance training. An exercise professional will advocate a number of exercises per body-part, across a number of planes of movement, with each exercise for a specific number of sets and repetitions (following warm-up sets), with the total duration on each muscle equaling a minimum of fifteen minutes. Yet the same exercise professional will probably recommend only one stretch, in one plane of movement, for one set, lasting a total of fifteen to thirty seconds. Should it be considered a 'no-brainer' that studies are inconclusive and stretching practices are equivocal with regards to effects on injury prevention, rehabilitation and sports performance? The best way to stretch has not yet received consensus, and steps to find such a consensus are being inhibited through poor studies, based on poor trends in practice.

In the study by Gribble et al (1999), we are left with a comparison of muscle stretches in a static only technique lasting for 30 seconds, compared with a hold-relax stretch with a static component lasting only eighteen seconds. How can we use this to draw real useable conclusions? If there is no consensus as to the correct application of static stretching, is it wise to now be recommending dynamic flexibility techniques which have even less base of evidence to work from? The problem here is that the industry trends are based on scant evidence, and whilst the scientists are working to improve our base of knowledge, industry 'leaders' are teaching flexibility practices that are without support.



PNF Stretching Techniques and Application



During normal stretching of a muscle, a myotatic (stretch) reflex, is activated which prevents further muscle lengthening. This reflex is useful to prevent musculotendinous injury, by preventing the muscle-tendon unit from being stretched passed its' normal passive range of movement. During stretching techniques, it is often the goal to diminish this myotatic response, so as to permit the muscle to be lengthened further. PNF techniques in particular, are believed to effectively diminish the myotatic reflex, and are consequently believed to be the most effective for increasing muscle length and therefore joint range of motion (Goss-Sampson et al, 2003; Carter et al, 2000; Gribble et al, 1999).



In a study by Carter et al (2000), the authors concluded that PNF stretching techniques effectively diminished muscular activity of the biceps femoris, which was apparently due to an inhibition of the myotatic reflex and would therefore permit greater muscle stretching. Chan et al (2001), found that PNF hamstring stretching increased hip flexion by 11.2o and 8.9o for an eight-week and four-week training program, respectively. The eight week group stretched for one set of 30 seconds, three times a week. The four week group stretched for two sets, with a one minute rest interval between sets, three times a week. Prior to the static stretch component each subject held an isometric contraction in the agonist muscle lasting three to six seconds. The increase in range of motion was the result of a total of 3600 seconds of stretching for both groups. This study suggests that gains in ROM become most significant, not with increased frequency or duration of stretch, or the number of repetitions or sets, but with the number of weeks that stretching is included in the program. This is not to say that the other variables are not involved, but specifically that changes in the muscle itself occur with recovery from stretching sessions, just as the effects of resistance training and cardiovascular training also occur with recovery time following overload (Chan et al, 2001).



Despite an increase in ROM, associated with the effectiveness of a flexibility training intervention, the underlying mechanisms and physiology are poorly understood. The exercise professional and scientist alike, must surely find it an arduous task to make recommendations for improving flexibility, if they do not understand how flexibility is actually improved. So what can be taken from this article and the scientific literature in general? Well, it can be said that there are a number of reasons for improving flexibility, and some examples have hereby been given that detail how it may be achieved. The literature suggest that there is little long-term difference between static and PNF techniques. Furthermore, the literature shows that it is necessary to include a stretching program three times a week, with stretches held for minimum of 30 seconds, for at least one set. As the study by Chan et al (2001) shows, 3600 seconds of stretching improves muscle length, whether that be 3600 seconds spread out over eight weeks or four weeks. The most significant gains, however, came with the eight-week program, suggesting that recovery from exercise sessions plays an important role. Muscles may also become more efficient at adapting to flexibility training as a long-term effect of a stretching program. This may be in a similar manner to how strength training becomes more efficient as more neuromuscular pathways are introduced.



Addressing the various issues of using flexibility training to decrease injury risk, to rehabilitate muscle damage or to improve sports performance, is outside of the scope of the current article. These issues will be referred to in greater detail in the coming articles in this series. The first step for the exercise professional is to start considering flexibility training in a similar manner to how other resistance and cardiovascular training is considered. To improve flexibility around a particular joint, the muscles involved should be stretched through a number of planes of movement, for at least one set of thirty seconds, in regular stretching programs. These programs should be adhered to for at least four weeks for long-term improvements to be imposed on the trained muscles.

[Mop]

A unique flexibility program is offered with the Resist-A-Ball® due to its dynamic nature. There are many benefits and advantages to stretching on the ball. We have listed several of these for your review. When attempting any of these stretches always begin in a position that is appropriate for your skill level. Remember that you have the added challenge of balance and stabilization because of the rolling nature of the ball. Controlling your movement is the key for efficient and injury free stretching exercises. We hope the exercises below will enhance and add variety to your flexibility program.

Benefits of Stretching with Resist-A-Ball®:

* With most stretches on the ball you have certain muscles working to stabilize the body as you focus on the muscles being stretched, resulting in increased strength gains.
* The ball allows smooth and rhythmic transitions as you roll into more intense stretches or into other positions.
* In most cases, the ball is providing a base of support, reducing stress on other joints.
* The ball enables you to achieve positions that are off the floor and its curved surface may also enable you to get into positions that are not possible on a floor or chair.
* The ball allows you to achieve positions that traction the spine, reducing compression and encouraging spinal muscles to relax.
* The ball is a valuable tool for flexibility for pre- and post-injury rehabilitation, proven in the physical therapy arena.
* Due to the balance challenge, the ball provides sensory motor challenges in various planes stimulating proprioceptive awareness.
* The ball encourages a sense of play resulting in a new and fun way to stretch and add variety to your programs.

MS = Muscle(s) Stretched
Trunk Stretches

Seated Lateral Trunk Stretch (Hips dropped to side)

Shift your weight to one side as you let your hips drop toward the floor; reach overhead and laterally flex your spine.



MS - Quadratus Lumborum, Lats, Trapezius (lower fibers),
Deltoids, Obliques

Supine Trunk Traction

Starting from an inclined position let your upper body drape back over the ball with the head supported. (One hand should be supporting the head.) Extend the legs as you continue to drape your body backwards over the ball. To return to an incline position, drop your hips and bend your knees keeping your head supported.



Bent Legs Extended Legs
MS - Spinal Flexors; Hip Flexors (extended leg)

Prone Over Ball Trunk Traction

Center your weight on top of the ball until there is no tension on the lower back.


MS - Spinal Erectors

Supine EL Rotary Torso Stretch

Roll the ball to the side with control.


MS - Spinal Rotators

Upper Body Stretches

Supine/Incline Chest Stretch

Drape the head and upper torso backwards over the ball with arms extended out to the side.

MS - Pectoralis Major, Anterior Deltoid

Prone Kneeling Lat Stretch

Roll the ball forward as you bend at the hips, keeping the hips stacked over the knees. Roll the ball side to side for a variation.



MS - Lats and Deltoids

Side-lying Lateral Cervical Traction

Lower the head towards the floor as you press the upper shoulder blade down towards the hip.



MS - Cervical Lateral Flexors, Levator Scapulae,
Trapezius (upper fibers)

Standing Shoulder Stretch at Wall

Roll the ball up the wall and lean towards the wall until a stretch is felt in the lats.



MS - Lats, Deltoids, Trapezius (lower fibers)
Combination: Trunk & Upper Body Stretches

Prone Kneeling “Thread the Needle” Stretch

Roll the ball forward as you bend at the hips, and slide one arm under the other arm as you rotate the spine. Keep the hips stacked over the knees.


MS - Spinal Rotators, Lats, Upper Back

Forward Bending Rotary Torso Stretch

Roll the ball across the body with one arm as you rotate the spine and pull the other arm behind you.



MS - Spinal Rotators, Deltoids, Chest, Biceps

[Mop]

BEFORE I post the artical i would like to state that PNF stretching is one of the best things you can do to your body - it takes someone that knows you and a lot of communication but truely is the best way to stretch. You can do it by yourself in some instances but you have to make sure you don't stretch to far or to hard while doing it.

Cliff Notes: PNF stretching basics - go into a stretch position - at the first point you feel tension you hold at that position for 5 - 15 seconds. Then flex the muscle for 2 - 3 seconds WHILE the body does not move at all. After the flex relax and pull the muscle further into a stretch. repeat these steps from 2 -5 times *

PNF stretching techniques have been widely used by physicians, physical therapists and athletic trainers. The theory behind PNF stretching is that it quickens neuromuscular responses by stimulating neural proprioceptors. Proprioceptors are nerve endings found in muscles, tendons, and joints which are sensitive to changes in tension. One of these proprioceptors, the Golgi Tendon Organ (GTO) is sensitive to an increase in tension within muscles. When activated the GTO causes the muscle to relax. If this occurs in the same muscle experiencing the increased tension, the result is what we call autogenic inhibition. PNF stretching is very advanced stretching technique and involves a variety of strategies to provide many results. It can be done alone, however it is typically performed with a partner who provides resistance and helps increase the range of motion. The most common form of PNF stretching is the contract-relax method. This method uses a muscle contraction followed by passive stretching. It is usually repeated several times. It is also recommended to mildly stimulate the opposing muscle group in order to return to neuromuscular balance. PNF stretching can be slightly uncomfortable for your clients when compared to static stretching, and should be performed with a knowledgeable and experienced professional (1,2).When describing PNF stretches, the antagonist muscle refers to the muscle that is being stretched and the agonist muscle refers to the muscle that is opposite the antagonist. For example, during knee flexion the leg extensors (quadriceps) will be stretched; they are the antagonist muscle group and the leg flexors (hamstrings), which cause the movement, are the agonist muscle group (1,2).

During PNF stretches, three techniques are used to increase the range of motion. The three PNF stretching techniques are: (1) hold-relax, (2) hold-relax with agonist muscle contraction, and (3) contract-relax. It is recommended that these stretching techniques are completed in three phases. To begin, a passive stretch lasting 10-seconds is recommended. This “pre-stretch” establishes the client’s current flexibility limits. The stretching techniques differ based on the muscle contractions used in the second and third phases (1,2). Both isometric and concentric muscle contractions of the antagonist are used before applying a passive stretch of the antagonist to bring about autogenic inhibition. The isometric muscle contraction is termed “hold” and the concentric muscle contraction is termed “contract.” A concentric muscle contraction of the agonist is used during passive stretching of the antagonist muscle group to cause reciprocal inhibition. The concentric muscle contraction of the agonist muscle group is termed “agonist contraction.” Each PNF stretching technique also involves passive static stretches called “relax.” (1,2).

So what does the research say about PNF stretching? The original theory that PNF stretching techniques increase range of motion through reciprocal muscle inhibition, which decreases electromyographic activity, was disproved in 1979 (3) and again in 1980 and 1990 (4,5). Electromyographic activity shows that muscles are silent during normal stretches until end range of motion nears (2). PNF techniques, however increase electrical activity and muscle stiffness during the stretch (3,4,5,6), despite the increase in range of motion. This suggests that the muscle undergoing PNF stretching eccentrically contracts, which some clinicians consider potentially more dangerous than having no electrical activity in the muscle (2). Both PNF and ballistic stretching cause the muscle to eccentricly contract. However, PNF stretching appears to have a more pronounced analgesic effect than ballistic stretching. The benefits of the greater increase in range of motion should be balanced against a theoretical increase in the risk of injury. There is currently no data on risk of injury due to PNF stretching. For those personal trainers who want to use static stretching, one study (7) reported that static stretching (continuous stretching without rest) is superior to cyclic stretching (applying a stretch, relaxing, and reapplying the stretch), whereas two studies (8,9) suggested no difference. Since the results of these studies are mixed more research is needed to make a sound decision.

In general, PNF stretching has resulted in larger increases in range of motion when compared to static or ballistic stretching (10,11-17), though some study results have not shown statistical significance the trend is still present (16-20). When comparing the three different types of PNF techniques, the agonist-contract-relax method appears to produce the best results followed by the contract-relax method (10,15-17), and lastly the hold-relax technique (10,15-17,21). If you happen to be working with a female client who is looking for an increased vertical jump, research done by Church et al (22) suggests that performing PNF stretching just prior to the activity actually had a detrimental effect on vertical jump performance.

In regards to the middle aged and elderly clients, the effects of PNF stretching techniques are unknown and the physiological changes associated with aging may lead to differential responses to PNF stretching. Ferber et al (23) conducted a study to look at the response of PNF stretching on the elderly aged 50-75. They found that PNF stretching using agonist contract-relax can increase ROM in the elderly; however it was observed that PNF stretching may not help muscular relaxation despite the increased joint ROM. Therefore, Ferber et al (23) suggest caution be used when contemplating whether to use PNF stretching on aged clients due to potential age induced changes in muscle elasticity. Cornelius et al (24) found that PNF stretching was effective for increasing ROM, however, if a non-hypertensive person completed one or two trials of PNF stretching, systolic blood pressure was not increased. But if a participant completed three trials they experienced a statistically significant increase in systolic blood pressure.

In conclusion, there are many research studies that suggest PNF stretching techniques increase the ROM of their participants; however there are other potential dangers and lingering individual factors that are associated with detrimental effects of PNF stretching. Therefore, it is prudent for personal trainers to weigh the potential risks and benefits of performing PNF stretching techniques on your clients. More research is needed for us to make more informed conclusions on PNF stretching for different populations.