Flexibility: Flex + Ability = Flexibility. Where as Flex is to bend or to resist breaking, and Ability is a skill or talent. Flexibility becomes the skill of controlling the range of motion and movement capacity of your physical structure. Flexibility is developed by special exercises called stretches, which involve the elongation of muscles, connective tissues, and other tissues.
There are six types of flexibility. They are classified based on the muscle's action and whether or not there is an external force acting to maintain or aid an increase in the range of motion. They include:
Of the six types of flexibility, only three are usually deliberately developed. They include dynamic active, static active, and static passive (below the pain threshold). Let's talk a bit about them...
This type of flexibility involves performing dynamic movements within a full range of motion in the joints (like kicks and arm swings). Dynamic stretching is what is used to develop dynamic active flexibility; It can be described as the combination of relaxing extended muscles while contracting moving muscles through a path of motion.
Dynamic flexibility plays a very important role in the practice of tricking. It's required for full extensions of kicks and the fluidness of twists among other things. Take a look at this second set of thumbnails illustrating tricks that portray high levels of dynamic flexibility:
This type of flexibility involves assuming and maintaining extended positions using only the tension of the agonists and synergists while the antagonists are being stretched. The best example of this type of flexibility is holding a standing kick high in the air for several seconds with no support. It is developed through active stretching, a combination of simultaneously relaxing the extended muscles while maintaining the stretched position using only the static-strength of the contracting muscles.
Static-active flexibility doesn't play a very strong role in tricking. Most tricks are dynamic in nature, there is no pause or intermission during technique or combination. While not important, that doesn't mean it's not impressive or useful. It becomes a display all of its own once developed to very high levels and it is a form of strength development too.
This type of flexibility involves assuming and maintaining extended positions using an external force (such as the strength of assisting limbs, a partner, or your own body weight.) The splits come to mind when one thinks of high levels of static passive flexibility. Other people may think about freakish snake ladies with their noses in their own rears; Hey! Nothing against freakish snake ladies, but what they do is seriously freakish. Static passive flexibility is developed through, (duh) Static passive stretches. Two methods that are generally received well are isometric stretching (PNF) and relaxed static stretching.
Some might question the use of developing this form of flexibility if the specific actions of the sport are dynamic in nature. Well, your flexibility isn't sufficiently developed if the maximal reach of motion doesn't somewhat exceed that required in your skill specifics. The success of performing said skills depends on the joint amplitude (range of motion), which has to be higher than that required by the sport. This difference between your flexibility and the needs of the sport is called either the flexibility reserve or tensility reserve. Finally, achieving the maximum speed in an exercise is impossible with no flexibility reserve, and may lead to various problems we've already covered in step one.
Thanks to Thomas Kurz for providing the information above regarding the six types of flexibility! His awesome book Stretching Scientifically, goes into more detail about that and so much more. Check it out! Here is the bibliographical reference again. :)
Kurz, Thomas. 2003. Stretching Scientifically: A Guide to Flexibility Training. Island Pond, VT: Stadion Publishing, Inc.
A lot happens haha! When a muscle is suddenly stretched, the nervous system sends out a flag called the stretch reflex. This reflex causes the muscle to contract, thus, putting a block on any further increase in amplitude to protect itself from harm. However, through training, the critical point at which this reflex is fired can be reset to a higher level. Also, with increased stretching over time, the number of muscle sarcomeres is thought to increase in series. These new sarcomeres are added onto the end of the existing myofibrils. This would explain an increase in flexibility by muscle length, but realistically, more research is actually needed to substantiate this claim.
With increased stretching over time the fascial sheaths encasing your muscles - the epimysium, endomysium, and perimysium may undergo semipermanent change in length. Other tissues adapting to the stretch include tendons, ligaments, fascia, and scar tissue.
Another theory suggests that muscle cells may control and modulate stiffness and elastic limit coordinately by selective expression of specific titan isoforms. Meaning, some muscular tissue in the body is better suited for flexibility increase than others.
Stretching is thought to stimulate the production and retention of gel-like substances called glycoaminoglycans (GAGs). These GAGs, along with water and hyaluronic acid, lubricate connective tissue fibers, maintaining a critical distance between them. This prevents the fibers from touching one another and sticking together. As a result, excessive cross-linkages are not formed.
Last, it has been suggested that stretching or resistance training of muscle and connective tissue may affect gene expression. This may alter tissue variants, which would influence muscle and connective tissue extensibility.
Thanks to these suggestive explanations, it's obvious that increasing flexibility depends on more than a single factor and that a lot of crap happens during stretching.
Flexibility
is affected by the form, type, and structure of a joint. Ligaments and
tendons also affect flexibility. The more elastic they are, the greater
the amplitude of a movement.
Gender
affects flexibility. Females tend to have a greater range of motion in
the hip joint and in the elbow due to differences in the bone
structure. Females also have more compliant ligaments and usually less
muscle mass around the joints, which decreases resistance in the
passive range of flexion.
Age
has a great impact on flexibility levels. Small children are generally
very supple, this flexibility decreases until puberty when it increases
throughout adolescence. After adolescence, flexibility tends to
decrease with age; This decrease can be minimized, however, in those
that remain active and engage in regular strength training. Physical
changes assosciated with a loss of flexibility in aging people include:
Increased calcium deposits, increased dehydration in connective
tissues, increased adhesions and cross-links in the connective tissues,
chemical structural changes of the tissues, and muscle fibers being
replaced with fatty and fibrous (collagen) fibers.
Your
emotional state can even impact your flexibility levels! Flexibility
increases during excitement and happiness. The next time you are so
excited you feel the need to pee your pants, consider tricking or
stretching instead. Tricking too? Yep, the connections between the
cerebellum and the areas of your brain that govern emotions make
muscular tonus and coordination dependent on these emotions, and vice versa.
So the opposite is also true. Negative emotions and fatigue can
adversely affect flexibility and coordination. Consider this next time
you stretch or trick.
Your
flexibility varies in accordance to the time of day. It is at its
lowest in the morning upon waking due to a lowered muscle tonus and a
lowered body temperature. However, this doesn't mean the morning is a
bad time to stretch. In fact, it has become popular to do dynamic
stretching in the morning upon waking to reset certain nervous
regulations of your muscles.
The sequencing of stretches in a workout can affect your flexibility. For example, if you wanted to improve your maximum stretch in the front split, you might find it wise to precede this position with some preliminary stretches. Deep lunges, hamstring stretches, and calf stretches are some example preliminary
holds to utilize prior to training a split.
The
arrangement of flexibility exercises in a workout can have an impact on
the amplitude of your movements. If you do dynamic stretching when greatly fatigued at the end of a training session, the amplitude of your movements could be diminished. A warm-up preceding static-passive stretching will result in better gains. Correct arrangement of stretching exercises in a workout is discussed below.
The
initial and resulting position of a stretch can affect your flexibility
development in the short and long term. For example, if you wish to
display a traditional upright sidesplit and you begin and end the
position with your pelvis tilted too far back, you will not be training
this particular position for success. Just like tricking, there is a
technique to each stretch. If you wish to emphasize flexibility gains
and safety you must ensure your position is sound.
Rhythm of movements? Yep. Bouncing and jerking (Ballistic stretching) alarms the stretch reflex when working with passive flexibility exercises. In dynamic stretching, lack of control and flinging of limbs instead of having a smooth, controlled stretch jeopardizes your safety. Without proper rhythm, you risk dismal flexibility progression or the possibility of harming yourself. Others could get hurt too, or die; Especially your family. So: Have good rhythm while you stretch or you and your family might die.
Your stretching method affects your flexibility levels. If you utilize muscular tensions in static-passive stretching (Meaning you would be doing isometric or PNF stretching), this could warrant quicker or greater gains in flexibility than relaxed stretching! The amount of time you hold a stretch can affect gains. If you decide that eating one dozen bananas and an entire watermelon is a good method of increasing dynamic flexibility, then you might explode.
A lack of strength throughout the range of motion can have an affect on your flexibility levels. Note: Keep in mind that strength and muscle size do not have a direct correlation to each other. Strong muscles tense less than weaker ones to support the same load; Thus, they are able to create stronger tensions. Tensions can diminish the stretch reflex, this enhances amplitude. The stronger the better.
Flexibility
can be worsened by spending too much training time moving joints
through a shortened range of motion. Hockey players, basketball
players, wrestlers, and cyclist, for example, spend most of their
activity time in a crouched position. This crouching results in
shortened hip and knee flexors in all three of these respective sports.
However, this shortening can be minimized through general exercise and
regular stretching. If you regularly participate in other sports,
consider analyzing the common competitive position and applying
stretches that fix any problems. I enjoy roller blading as a form of
aerobic activity, so just like the hockey players, I have to keep an
awareness of this and A) Maintain flexibility in those regions being used through a shortened range of motion. And/Or. B) Don't roller blade three hours a day, seven days a week. Haha... 
Your
overall body temperature and the specific muscle temperature have an
influence on your flexibility levels. Generally, activity (Such as pre-training warm up)
increases these temperatures which increases amplitude. A temperature
decrease resulting from inactivity, reduces flexibility levels. Locally
applied heat does not have the same effect. The reason is because
physical activity intensifies blood irrigation of the muscles via
increased heart activity and vasodilation of blood vessels, this makes
muscle fibers more elastic. This blood irrigation also has an affect on
the tendons, joints, and ligaments. Activity also affects the nervous
system. Static Gamma motoneurons, which detect the magnitude of a
stretch and regulate the tension of intrafusal fibers in muscle
spindles, are stimulated by the cold center and inhibited by the heat
center in your hypothalamus. Thus, these motoneurons are easier to
activate when you are cool from inactivity, this results in
worsened flexibility levels. However, locally applied cold sources will
have a different affect, because local cooling reduces the sensitivity
of muscle spindles but not the Golgi organs.This topic will be brought up again later, but we will cover the brunt of it right now. So, where does flexibility fit in with tricking? Dynamic stretching should be part of a warmup, isometric stretching would be at the end of your tricking or training session, and relaxed static-passive stretching would be done in place of or with isometrics, and possibly at the end of the cooldown as well!
Understand? Want a detailed list? Tricking and stretching together in a well designed workout layout:
General warmup: Start with easy movements that limber up the joints, such as smooth circular movements and simplistic bending and twisting. Then follow this with some cardiovascular action, get that blood moving. Try to vary it up: Jogging is so trite. Dash back and forth, backwards, and side to side / Swings, leans, hops, skips, leaps, bounds, bowel loosening goodness. Jump rope is the yes, fancy jump rope work is the super yes. Just make it interesting.
Specific warmup: If you have a goal of increasing dynamic flexibility, now is the time to include that in your training session. Do the sets and reps you've chosen (More information ahead in step 3). Then to conclude the specific warmup you do prep work for various tricks you are going to bust this session. Hey, and if you are doing this for resistance training - go ahead and start adding on the plates and pyramiding your way up to gritty greatness.
Main workout: TRICKING! Or whatever...
Cooldown: If you want to train static-active flexibility I would include it at the end of your training session. If you are going to be working on improving static-passive flexibility by Isometric stretching do it last. You would probably do some light walking, stepping, or pre-trick movements to finalize the cooldown. What about Relaxed stretching? If done for cooldown purposes I would do them at this time. If done for flexibility improvement, do them in place of the isometric stretches or with them.
Dammit dude.. I'm confused! What if I just want to increase flexibility?
Yeah, well if this is the case skip the specific warmup and just do dynamic stretching and/or static-active stretching as the main part of your workout followed by passive stretches. Sound good? I'm sure it does. :)
Why can't I do static stretching before working out?
Relaxed static stretching decreases strength by impairing activation of the stretched muscles for up to five minutes following the stretch and contractile force for up to an hour. Yeah, it temporarily reduces maximal strength utilization. There is no evidence that pre-training static stretching reduces injury. Passive stretching has a calming effect and can actually make you sleepy. The list:
and...
So is it wise to stretch when you are sore? It really depends on the goal of the stretch. If your goal is to increase flexibility, you'll likely do more harm than good. If your goal is to relieve the soreness, light stretching is a great idea. Keyword: [LIGHT] Avoid isometrics and static-active stretches during these times, soreness is a sign of muscle tissue damage. Stretching exercises like these can compound the damage and delay recovery. Stick to light dynamic or relaxed stretching and perform only enough to feel relief. If we are talking about injury, you can probably do some slow dynamic stretches, or some gentle relaxed stretches, possibly some static-active stretches, but again: DO NOT focus on flexibility gains during these times. Avoid all exercises with strong muscular tensions as well as any movements at the maximum range of motion. When a muscular injury heals, it heals at a shorter length. Very light stretching, preferably light relaxed stretching, could help prevent an excessive loss of flexibility and sometimes relieve pain. Following an injury, it's essential to regain lost flexibility to prevent relapse. But, on a final note: DURING INJURY OR SORENESS - YOUR GOAL SHOULD NOT BE TO INCREASE FLEXIBILITY / ONLY RELIEVE PAIN OR PREVENT EXCESSIVE LOSS OF FLEXIBILITY. AHHHHH!!! The acid rain is burning right into your eyes! Again your dreams may lose the glooooooow!
You know, I think it's essential I just add this in. Everybody loves summarizations. I'm gonna make it short and just include the meat. If you don't understand any of the following, just read above!
This concludes the second step. You ready to dive into stretching? Let's go to step 3!