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Over the past several years, the athletes, trainers and therapists have come to recognize the importance of flexibility training in the quest for high performance. If you want to reach your best performance, you need to understand flexibility training. To understand how to improve flexibility, you have to have a basic grasp of the main mechanisms which restrict your flexibility in the first place.

Neurological factors:

Your central and peripheral nervous systems have control mechanisms designed to keep you from accidentally moving beyond your structural limits. These systems act to contract the muscles which you are elongating in order to limit the rate (speed of movement) and amount of elongation during any movement which requires muscle lengthening. The sensation you feel is pain and apprehension or tightening up when these mechanisms kick in. Luckily, this is one of the most easily modified systems affecting your flexibility. In order to overcome this barrier, you have to do two things,


  1. Move slowly from a normal position into the end range of any stretch. It is preferable to move in stages, giving the stretch receptors in the muscle time to acclimatize to the new position before moving on. Several techniques falling under the heading of Proprioceptive Neuromuscular Facilitation (PNF) are very effective at accelerating this adaptation. Agonist contract-relax (often simply called Contract-Relax) techniques can be used to more quickly acclimate the receptors into thinking that the new stretch position is within the normal range. For a great description of how this system works, refer to Kit Laughlin's excellent book Stretching and Flexibility. You can also use a variation of PNF called Antagonist Contract-Relax to inhibit the stretching muscle from contracting by contracting its opposing muscle (antagonist). This method results in increased range and a new motor patterning in the target muscle (agonist), which helps the retention of new flexibility. Pavel Tsatsouline demonstrates some stretches using this method (he calls it "The Pink Panther") in his book Relax into Stretch.
  2. Increase your exposure to end range positions. Most of us spend the greater part of our time in very few static or repetitive positions (sitting, standing, walking, and lying down). This results in a neuromuscular learning effect, telling our bodies that these positions are "normal" and that other positions are unusual and potentially dangerous. You can notice this effect in the elderly, who progressively limit their movements until they can hardly move at all. Simply forcing ourselves to use more movement in our daily activities will improve flexibility and enhance retention of newly gained flexibility. As the old adage states: "If you don't use it you lose it." Crouching, bending, twisting, lunging and reaching will all help you become more flexible.

Myogenic Factors:

Simply put; the bigger and stronger your muscles are (greater cross sectional area) the more difficult it will be to stretch them. This is probably the least important of the restrictive factors, since the actual structure of your muscle tissue (not including the connective tissue it is invested in) is very plastic and prone to changes in length. This being said, if you have a very large muscle on the inside of a joint which you are trying to close (example - hamstrings and calves in knee flexion), you may experience some movement restriction if the muscle gets in the way. When you experience this type of movement limitation in a joint, it is typically because the muscle inside the joint is in a mild state of spasm. A common example of this occurs when you try to stretch one side of your rib cage by leaning sideways, and the other side tightens up. In this case, alternating the stretch between the muscles of either side will yield better results. Alternatively, sports massage can often help remedy this type of situation.

FullSizeRender-1Connective Tissue Factors: 

Considering the number of layers of connective tissue you have, it is not surprising that this factor can be of great importance in range of motion. From the very smallest of myofibrils, through muscle fibers, fascicular bundles, whole muscles and all the way up to entire muscular chains, each grouping of fibers is invested in its own layer of connective tissue. This tissue is non-elastic and has a tensile strength relative to its weight greater than the tensile strength of structural steel. Connective tissue from each muscle fiber is contiguous with the muscle tendons and is used to transfer force to the skeletal attachments. On top of all this (literally) we have layers of superficial connective tissue, which form a basement layer for your skin and allow your muscles to contract independently without pulling your skin along with them (pinch the skin over your bicep and see how it moves independently of the muscle). Superficial connective tissue is connected to your skeleton at a few key places (spine of shoulder blade, hands, feet, spine, iliac crest, and skull). These attachments keep your skin in place relative to your skeleton. Your skin does not slide in these places. Otherwise your ass might end up where your elbow should be. When stretching, your connective tissue becomes a factor when:
  1. you perform a multi-joint movement which elongates the superficial connective tissue (you will feel a non-localized burning stretch sensation);
  2. you reach the muscle tissue end of range and begin elongating the muscle's connective tissue layers (you will feel a local burning stretch sensation). The second condition happens more frequently in muscles with thicker connective tissue layers, like the calf and hamstring.
Using PNF techniques will help move further into a stretch and increase the effect on the connective tissue, but in my experience, the best way to increase connective tissue length is to either maintain end range positions for longer intervals or reach these end positions frequently. Myo-fascial stretching techniques of the type taught by osteopath Dr Guy Voyer and his school are extremely helpful in elongating specific myofascial chains. These techniques involve positioning all body segments in such a way as to increase tension against a specific chain of fascia. Though somewhat unpleasant and sometimes complex, these techniques are highly effective. To learn these techniques, your best bet is to work with a skilled instructor who is familiar with these techniques for at least a few sessions, they should be able to identify which chains are restricting your movement and teach you the correct positioning for specific stretches for these chains.
In some cases, scarring of connective tissue due to trauma or overuse injuries can restrict movement by adhering muscles, nerves and/or superficial connective tissues together. In these cases soft tissue treatments like Active Release Techniques®, Structural Integration or Adaptive Bodywork techniques can be extremely helpful in returning to complete range of motion or in breaking through flexibility barriers.

Structural Factors:

Stretch 5In certain cases, flexibility restrictions may be due to actual limitations in the structures of joints and the tissues directly surrounding these joints. Joint sizes, bone sizes and lengths, as well as thickness of cartilage, depth of joint capsules and joint or bone degeneration will all play a role in range of motion. Large boned people are rarely as flexible as the tiny athletes who are often seen as contortionists, gymnasts and dancers. We cannot affect these factors in the short term, however, even our bony structures are plastic, and they remodel themselves (to some degree) in response to the stresses we apply. Maintaining large ranges of motion helps to eliminate negative remodelling of joint structures which would further limit our movements. As described in his book Super Seals, Pavel Tsatsouline sets out several great joint mobility regimens and exercises which I have found not only help maintain my joint lubrication and mobility, but can also serve as dynamic warm-ups to a flexibility training workout.
In summary, in order to improve flexibility, we must use a variety of techniques to address neurological, myogenic, connective tissue and structural factors. By including some or all of these techniques into your flexibility training workouts you are on the road to optimal results.

In closing, I leave you with a quote from Australian flexibility guru Kit Laughlin (from his book Stretching and Flexibility) on optimal frequency for flexibility training:

"One of the early ones (claims - ed.) was to test the often-made claim that a diligent student needs to stretch every day in order to become flexible. And as most people know, this same claim is made by dance and gymnastics teachers too. So we divided our students into four groups: those that did the same poses every day, those that did them every second day, every third day, and the lazy ones that did them just once a week. I should say that in these tests we asked the students to do hard hamstring poses and difficult quadriceps stretches on the assumption that these areas were the ones that most people wanted to improve, and (in the case of hamstrings in particular) were among their tightest muscles. To my surprise, the once-every-third-day and the once-a-week groups consistently made faster progress than the other two groups."

Sébastien Boucher for Clinique Sportive HPH

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