Information on
Flexibility & Stretching

Factors Limiting Flexibility
Cooperating Muscle Groups
Preparing to Stretch
Warming up - The First Step
Warm-up Stretching
Types of Flexibility
How Connective Tissue Affects Flexibility
Overflexibility
Types of Muscle Contraction
What Happens When You Stretch

Factors Limiting Flexibility [top]

Flexibility or mobility, to use another term, is affected by both internal and external factors. It's important to be aware of both.

Internal Factors

The type of joint you want to stretch. Some joints just aren't meant to be flexible
The internal resistance within a joint
Bony structures which might limit movement
Previous injuries that have caused scar tissue to limit the elasticity of the muscle
The limited elasticity of tendons and ligaments. Ligaments don't stretch much and tendons shouldn't stretch at all
How elastic your skin is
The ability of a muscle to relax and contract within a range of motion
The temperature of the joint and associated tissues. Joints and tissues stretch more easily when the body temperature is one or two degrees higher than normal.

External Factors

The temperature of the place where you are stretching - it's easier when the atmosphere is warmer
The time of day in that most people are more flexible in the afternoon rather than in the morning after hours of inactivity (sleep)
If you are recovering from an injury it will be harder to stretch until the injured part is healed
Age - pre-adolescents are usually more flexible than older adolescents or adults
Gender - females (sorry guys!) are usually more flexible than males
Your ability to perform a particular exercise in that practice makes it easier
Your commitment to achieving your optimal flexibility
The restrictions of clothing and/or equipment used.

Some of the other factors that might impact on your flexibility include your bone structure, in that age can contribute to the inflexibility of joints; muscle mass, where the muscle is so heavily developed, such as a hamstring, that it limits the ability for a complete range of motion to occur; excess fatty tissue around a joint may also inhibit a good stretch. It is also easier to stretch when your body is well-hydrated. If your muscle tissue begins to "dry" for lack of water, it will be more difficult to stretch adequately.

Cooperating Muscle Groups [top]

When muscles cause a limb to move through it's range of motion, they usually act in one of the following cooperating groups:

• Agonist - These muscles cause the movement to occur. They create the normal range of motion in a joint by contracting. Agonists are also referred to as "prime movers" since they are the muscles that are primarily responsible for generating the movement.
• Antagonist - These muscles act in opposition to the movement generated by the agonists and are responsible for returning a limb to its initial position.
• Synergists - These muscles perform, or help in performing, the same set of joint motion as the agonists do. Synegists are sometimes referred to as "neutralizers" because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.
• Fixators - These muscles provide the necessary support to assist in holding the rest of the body in place while the movement occurs. This process helps to stabilize the muscle.

For example: when you flex your knee, your hamstring contracts as well as your calf and buttock. These are the agonists. Meanwhile, your quad relaxes allowing for the motion to occur and serves as the antagonist. The calves and buttocks serve as the synergists. Agonists and antagonists are usually located on opposite sides of the joint, like your biceps and triceps, while synergists are usually located on the same side of the joint near the agonist. The following is a list of commonly used agonist/antagonist muscle pairs:

• Pectorals/latissimus dorsi (pecs and lats)
• Anterior deltoids/posterior deltoids (front and back shoulders)
• Trapezius/deltoids (traps and delts)
• Abdominals/spinal erectors (abs and lower back)
• Left and right external obliques (sides)
• Quadriceps/hamstrings (quads and hams)
• Shins/calves
• Biceps/triceps
• Forearm flexors/extensors

Preparing to Stretch [top]

When proper and regular stretching become an integral part of your conditioning program, you will be accomplishing far more than just becoming more flexible. Some of the other benefits of stretching include:

• enhanced physicial fitness
• enhanced ability to learn and perform skilled movements
• better mental and physical relaxation
• keener development of body awareness
• reduced risk of injury to joints, muscles, and tendons
• reduced muscular soreness and tension
• increased suppleness
• speedier recovery from strenuous activities

Unfortunately, athletes who do stretch often do not stretch properly and do not reap the benefits of a good, positive stretching program. Some of the more common mistakes athletes make when stretching are:

• inappropriate warm-up
• inadequate rest between workouts
• overstretching
• doing the wrong exercises
• performing exercises in the wrong sequence
• being dehydrated
• bouncing into stretches

So, now that you are terrified to stretch, let's put this discussion into perspective and discuss the best ways to prepare for flexibility and to learn about the various methods to stretch for maximum benefit.

Warming up - The First Step [top]

Let's begin with a little anatomy lesson (not to worry, this will be easy!) For the most part muscles are attached to tendons and tendons attach to ligaments at the various joints in your body. There are usually at least two bones that come together at a joint in a variety of ways. Because bones can't touch each other, there is cartilage - a gelatinous materials filled with fluid that lubricates the joint. As you put pressure on a joint, the cartilage squeezes out the fluid, called "synovial fluid," lubricating the area and then, when you release the tension, the cartilage retrieves the fluid much like the action of a sponge.

A similar process occurs within your automobile's engine. Your car's engine needs motor oil, a lubricant, with the crankcase so that the pistons do not rub against each other. The oil bathes the pistons and moving parts, so the action is smooth. When you first start your car's engine on a cold morning, the engine sounds a little loud. That's because the oil in the case is cold and sluggish, not doing it's best job. After a while, the oil warms up. When fluid is warmed, it expands giving more cushion to the moving parts.

The same process occurs in your body. When you first start to move, the synovial fluid in your joints is cold and somewhat sluggish. But as you move around, it warms up, increases in volume, and provides a better cushion and lubrication. That's why you must perform a general warm up before stretching.

The general warm-up is divided into two basic parts: Joint rotations and aerobic activities.

Joint Rotations

The best, and easiest way to begin a slow general warm-up is by employing joint rotations at each of your body's joints. This general warm-up should begin at either your toes working upward or from your head working downward. Take each joint through slow clockwise and counterclockwise movements or follow the natural flow of your joint. For example, when warming up your shoulders, they can be raised and lowered; rotated forward and backward; or your shoulder can be taken through a complete 360° movement.

All these motions facilitates joint motion by lubricating the entire joint with synovial fluid. This permits your joints to function more easily when called upon to participate in your athletic activity. Use the following order in either direction:

• fingers and knuckles
• wrists
• elbows
• shoulders
• neck
• trunk/waist
• hips
• legs
• knees
• ankles
• toes

In addition to a gentle, easy general warm-up, there is another definite advantage to this process. You will begin to feel your body move more smoothly and flexibly without expending large amounts of energyto accomplish this. Have you ever watched someone really stretch and stretch for a long period of time? That person is using lots of energy that should be reserved for competition itself - not getting ready forthe competition.

Aerobic Activity

After you have finished your joint warm-up routine, it is time to continue to warm your body through some aerobic activity. You should engage in a minimum of five minutes of some activity such as jump roping, jogging, light calisthenics or similar activity that will cause an increase in your cardiovascular output (your heart should pump faster during this period). The purpose of this activity is to raise your body's core temperature and get your blood flowing. Increased blood flow in the muscles improves muscle performance and flexibility and reduces the likelihood of injury.

Warm-up Stretching [top]

The stretching phase of your warmup consists of two parts: static and dynamic stretching. You should start this phase with some static stretching before executing any dynamic movements. Dynamic stretching can result in over-stretching leading to potential injury, so to assure that from happening, learn to accomplish the static phase first.

Once the general warm-up has been completed, the muscles are warmer and more elastic. Immediately following your general warm-up, you should begin in a slow, relaxed, manner to stretch. You should start with your back, followed by your upper body and lower body, stretching your muscles in the following order:

1. back
2. sides (external obliques)
3. neck
4. forearms and wrists
5. triceps
6. chest
7. buttocks
8. groin (adductors)
9. thighs (quadriceps and abductors)
10. calves
11. shins
12. hamstrings
13. instep

You should carefully review the Student/Athlete "Flexibility" section for your sport to learn more about the specific static stretches beneficial to your individual requirements.

Dynamic Warm-Up Stretching

Once you have completed your static warm-up stretches, you should begin to execute some dynamic stretches. Dynamic stretches involve motion, whereas static stretching does not. These stretches involve taking your joints through their range of motion. They could include: leg raises, shoulder rotations, arm circles, leg adductions/abductions, ankle rolls. The focus here is to continue to warm your body's soft tissue. Once you are adequately warmed up, you can concentrate on stretching those muscle groups with which you will execute your sport.

Types of Flexibility [top]

Many athletes are unaware that there are different types of flexibility. They are grouped according to the various types of activities involved in the athlete's training program. There are three types:

Dynamic Flexibility - As we have discussed previously, dynamic flexibility is the ability to perform dynamic movements ofthe muscles to bring a limb through its full range of motion in the joints. Do not confuse dynamic flexibility with "ballistic stretching." Dynamic flexibility consists of controlled leg and arm swings that takeyou gently to the limits of your range of motion. Ballistic flexibility involves a "bouncing" movement and is considered dangerous because it forces the muscle beyond its range of motion rather than just to its full range. Ballistic stretching can lead to injuries.

Static-Active Flexibility - Static-Active Flexibilitiy is the ability to assume and maintain extended positions using only the tension of the agonists and synergists while the antagonists are being stretched. For example, lifting the leg high and holding it. In other words, with static-active flexibility, you assume a position and then hold it there with no assistance other than using the strength of your agonist muscles. For example, when you bring your leg up high, the tension is in your quadriceps (agonists) allowing your hamstrings (antagonists) to relax. Active stretches increase flexibility and strengthens the agonistic muscles. Active stretches are difficult to hold for more than 10-15 seconds and rarely need to be held any longer. Many Yoga stretches are examples of static-active flexibility.

Static-Passive Flexibility - Static-Passive Flexibility is the ability to assume extended positions and then maintain them using only your weight, the support of your limbs, or some other apparatus such as a chair. This ability does not come soley from your muscles, but also from the apparatus you utilize. Passive stretching is also called "relaxed" stretching. Slow, relaxed stretching is useful in relieving spasms in muscles that are healing after an injury and relaxed stretching is also excellent for cooling down after a workout. This helps reduce the soreness and fatigue on over-worked muscles. Some people confuse "passive" with "static." They are not the same. "Static stretching" involves holding the position at the farthest point. "Passive stretching" is a technique in which you are relaxed and make no contribution to the range of motion. Rather, an external force is created by an outside source, either another person or an apparatus. Partner-assisted stretching is an example of this type of stretching.

How Connective Tissue Affects Flexibility [top]

It's time for another quick anatomy lesson! It's very important for an athlete to understand the role that the connective tissue which encompasses the soft tissue (muscles, tendons, etc.) in the body. Often, when you feel tight and/or inflexible, it is the connective tissue that is taut rather than the muscle within it. We will discuss various methods to alleviate this condition throughout this piece.

Connective tissue is located all around the muscle and its fibers. Connective tissue is composed of a base substance and two kinds of protein based fiber. The two types of fiber are collagenous connective tissue and elastic connective tissue. Collagenous connective tissue consists mostly of collagen and provides tensile strength. Elastic connective tissue consists mostly of elastin and provides elasticity. The base substance is both a lubricant (allowing fibers to easily slide over one another) and as a glue (holding the fibers of the tissue together into bundles).

The more elastic connective tissue there is around a joint, the greater the range of motion in that joint. Connective tissues are made up of tendons, ligaments, and the fascial sheaths that evelop, or bind, muscles into separate groups.

The resistance to lengthening that is offered by a muscle is dependent upon its connective tissues. When the muscle lengthens, the surrounding connective tissues become more taut. Also, inactivity of certain muscles or joints can cause chemical changes in connective tissue with restrict flexibility. The relative stiffness of joint tissue is a concern for most athletes. The joint capsule (near the end of the bones) is the most important area and usually accounts for almost half a person's muscle stiffness. It is very difficult to stretch this area and, therefore, most effort should be directed toward increasing the flexibility of the muscle's fascia or connective tissues. The reasons for this are twofold. First, muscle and its fascia have more elastic tissue, so they are more modifiable in terms of reducing resistance to elongation. Second, because ligaments and tendons have less elasticity than fascia, it is undesirable to produce too much slack in them. Overstretching these structures may weaken the integrity of joints. As a result, an excessive amount of flexibility may destabilize the joints and increase an athlete's risk of injury.

When connective tissue is overused, the tissue becomes fatigued and may tear, which also limits flexibility. When connective tissue is unused or under used, it provides significant resistance and limits flexibility. The elastin begins to fray and loses some of its elasticity, and the collagen increases in stiffness and in density. Aging has some of the same effects on connective tissue that lack of use produces.

Overflexibility [top]

Some athletes, after learning about the importance of flexibility, think that more is better. Be careful. It is possible for the muscles of a joint to become too flexible. There is a tradeoff between flexibility and stability. The looser you get, the less support offered to the joints by their adjacent muscles. Excessive flexibility can be just as much a liability as not enough flexibility. Either one increases your risk of injury.

Once a muscle has reached its absolute maximum length, attempting to stretch the muscle further only serves to stretch the ligaments and put undue stress upon the tendons (things you DO NOT WANT TO STRETCH!) Ligaments will tear when stretched more than 6% of their normal length. Tendons are not even supposed to be able to lengthen. Even when stretched ligaments and tendons do not tear, loose joints and/or a decrease in the joint's stability can occur. This greatly increases your risk of injury.

Types of Muscle Contraction [top]

The contraction of a muscle does not necessarily imply that the muscle shortens; it only means that tension has been generated. Muscles can contract in the following ways:

Isometric Contraction - This is a contraction in which no movement takes place, because the load on the muscle exceeds the tension generated by the contracting muscle. This occurs when a muscle attempts to push or pull an immovable object.

Isotonic Contraction - This is a contraction in which movement does occur, because the tension generated by the contracting muscle exceeds the load on the muscle. this occurs when you use your muscles to successfully push or pull an object. Isotonic contractions are further divided into two types:

• Concentric Contractions in which the muiscle decreases in length (shortens) against an opposing load, such as lifting a weight.
• Eccentric Contraction in which the muiscle increases in length (lengthens) as it resists a load, such as lowering a weight. During a concentric contraction, the agonists are the muscles that are doing all of the work. During an eccentric contraction, the antagonists do all the work.

What Happens When You Stretch [top]

The basic unit of a contraction in the muscle fiber is called a sarcomere. As the sarcomere contracts, the area of overlap between the thick and thin myofilaments increases. As it stretches, this area of overlap decreases, allowing the muscle fiber to lengthen. Once the muscle fiber is at its maximum resting length (all the sarcomeres are fully stretched), additional stretching places force on the surrounding connective tissue. As the tension increases, the collagen fibers in the connective tissue align themselves along the same line of force as the tension. Hence when you stretch, the muscle fiber is pulled out to its full length sarcomere by sarcomere, and then the connective tissue takes up the remaining slack. When this occurs, it helps to realign any disorganized fibers in the direction of the tension. This realignment is what helps to rehabilitate scarred tissue back to health.

When a muscle is stretched, some of its fibers lengthen, but other fibers may remain at rest. The current length of the entire muscle depends upon the number of stretched fibers.

Proprioceptors

The nerve endings that relay all the information about the musculoskeletal system to the central nervous system are called proprioceptors. They are the source of our body's perception of position and movement. The proprioceptors detect any changes in physical diisplacement and any changes in tension, or force, within the body. They are found in all nerve endings of the joints, muscles, and tendonds. The proprioceptors related to stretching are located in the tendons and in the muscle fibers. One of the proprioceptors that comes into play when we stretch is called the golgi tendon which is responsible for detecting changes in movement and pressure within the body.

When the fibers of a muscle lengthens, so do the muscle spindles. The muscle spindle contains different types of fibers which are sensitive to the change in muscle length and the rate of change in muscle length.When muscles contractit places tension on the tendons where the golgi tendon organ is located. The golgi tendon organ is sensitive to the change in tension and the rate of change of the tension.

Any you thought that stretching and flexibility was just bending over to touch your toes!