Most people think that mobility and flexibility are one and the same, when in fact they are two very different concepts. It is not only the muscles stretching over a joint but also how far the joint moves within the joint capsule. Mobility also takes into account the component of motor control within the nervous system. Countless scientific studies have failed to prove that stretching is able to be maintained long term.
Unless you have the time to sit in a stretch for 24 hours, unfortunately the effect is only temporary. If you are trying to stretch a muscle over a joint that has a mobility restriction you are going to get nowhere fast. Aging has some of the same effects on connective tissue that lack of use has. How Aging Affects Flexibility How Connective Tissue Affects Flexibility : previous subsection Factors Limiting Flexibility : beginning of section With appropriate training, flexibility can, and should, be developed at all ages.
This does not imply, however, that flexibility can be developed at the same rate by everyone. In general, the older you are, the longer it will take to develop the desired level of flexibility. Hopefully, you'll be more patient if you're older. Alter , the main reason we become less flexible as we get older is a result of certain changes that take place in our connective tissues.
As we age, our bodies gradually dehydrate to some extent. It is believed that "stretching stimulates the production or retention of lubricants between the connective tissue fibers, thus preventing the formation of adhesions". Hence, exercise can delay some of the loss of flexibility that occurs due to the aging process.
Alter further states that some of the physical changes attributed to aging are the following: An increased amount of calcium deposits, adhesions, and cross-links in the body An increase in the level of fragmentation and dehydration Changes in the chemical structure of the tissues. Loss of suppleness due to the replacement of muscle fibers with fatty, collagenous fibers.
This does not mean that you should give up trying to achieve flexibility if you are old or inflexible. It just means that you need to work harder, and more carefully, for a longer period of time when attempting to increase flexibility. Increases in the ability of muscle tissues and connective tissues to elongate stretch can be achieved at any age.
Strength and Flexibility Overflexibility : next section Factors Limiting Flexibility : previous section Flexibility : beginning of chapter Strength training and flexibility training should go hand in hand. It is a common misconception that there must always be a trade-off between flexibility and strength. Obviously, if you neglect flexibility training altogether in order to train for strength then you are certainly sacrificing flexibility and vice versa.
However, performing exercises for both strength and flexibility need not sacrifice either one. As a matter of fact, flexibility training and strength training can actually enhance one another. Static stretching of fatigued muscles see section Static Stretching performed immediately following the exercise s that caused the fatigue, helps not only to increase flexibility, but also enhances the promotion of muscular development muscle growth , and will actually help decrease the level of post-exercise soreness.
Here's why: After you have used weights or other means to overload and fatigue your muscles, your muscles retain a "pump" and are shortened somewhat. This "shortening" is due mostly to the repetition of intense muscle activity that often only takes the muscle through part of its full range of motion. This "pump" makes the muscle appear bigger. The "pumped" muscle is also full of lactic acid and other by-products from exhaustive exercise. If the muscle is not stretched afterward, it will retain this decreased range of motion it sort of "forgets" how to make itself as long as it could and the buildup of lactic acid will cause post-exercise soreness.
Static stretching of the "pumped" muscle helps it to become "looser", and to "remember" its full range of movement. It also helps to remove lactic acid and other waste-products from the muscle. While it is true that stretching the "pumped" muscle will make it appear visibly smaller, it does not decrease the muscle's size or inhibit muscle growth.
Numerous studies representing decades of research have noted the effectiveness of prolonged stretching at low to moderate levels of tension. Research has suggested that static stretches be held between 6 and 60 seconds, with to second holds most commonly being advocated. Some authors have proposed that a single static stretch of 15 to 30 seconds one time each day is sufficient for most people.
Research has shown that temperature has a significant influence on the mechanical behavior of connective tissue under tensile stretch. Because connective tissue is composed of collagen, which is resistant to stretch at normal body temperature, the effect of increased tissue temperature on stretch has been studied.
Synthesis of the body of research shows that higher therapeutic temperatures at low loads produce the greatest plastic tissue elongation with the least damage. Lentell et al reported greater increases in the range of motion of healthy shoulders after the application of heat. Increased connective tissue temperature decreases the resistance of connective tissue to stretch and promotes increased soft tissue extensibility. The use of ultrasound before joint mobilization has proved effective in elevating deep tissue temperature and extensibility.
This window indicates that for optimal tissue elongation, stretching should be performed during ultrasound treatment or within 3. In a follow-up study, Rose et al reported that after a 1-MHz ultrasound application, the deeper tissues cooled at a slower rate than did the superficial tissues; thus, the stretching window was open longer for deeper structures than for superficial ones.
Although superior stretching results have been reported with the application of heat before and during stretching, other studies have found greater increases in flexibility after the application of cold packs. Brodowicz et al reported improved hamstring flexibility in healthy subjects after 20 minutes of hamstring stretching with an ice pack applied to the posterior aspect of the thigh when compared with subjects who received heat or who performed stretching without the application of any therapeutic agent.
Kottke et al have also shown that greater plastic stretch results if the tissue is allowed to cool before tension is released, whereas others have reported that the use of cold during the end stages of stretching diminishes the cumulative gains in flexibility that occurred after the application of heat. Moreover, it appears that the use of either a superficial heat or a cold modality in conjunction with stretching results in greater improvements in flexibility than does stretching alone.
It remains to be seen whether increased extensibility is the sole result of a single structure or a combination of structural changes perhaps related to musculotendinous, capsuloligamentous, or fascial tissue. Range of motion and flexibility are measured in a number of different ways.
Typically, the type of tissue being assessed will dictate the method of assessment, although some methods may be used for various tissues. The primary movements that are assessed are termed as being physiologic or accessory. Physiologic movement accounts for the major portion of the range and can be measured with a goniometer see Chapter 5. Physiologic joint movements occur in the cardinal movement planes and include flexion-extension, abduction-adduction, and rotation.
Accessory motion, also referred to as arthrokinematics , is necessary for normal physiologic range of motion; it occurs simultaneously with physiologic motion and cannot be measured precisely. The ability to accurately assess and measure physiologic range of motion appears to be dependent on the joint. These findings are detailed in Chapter 5 , and the reader is encouraged to be innovative in developing improved methods of measurement to enhance those that currently exist. Devices, such as a sit-and-reach tool, can be used to assess excursion of the hamstring muscles Fig.
Accessory range of motion is much more difficult to assess and measure because it is often measured in units of millimeters. Studies have shown a clear difference between novice and expert clinicians in determining accessory range of motion. Equipment can also be used to assess accessory joint motion, such as that seen when one is measuring the amount of anterior translation of the knee as a result of injury to the anterior cruciate ligament Fig.
The limited joint range of motion caused by soft tissue restriction often inhibits initiation or completion of the rehabilitative process. Conservative treatment of contractures is only moderately successful, and overly aggressive stretching may result in undesired adverse effects.
Optimal stretching is achieved only when voluntary and reflexive muscle resistance is overcome or eliminated and tissue elongation is facilitated. The main types of tissue that are stretched include musculotendinous, capsuloligamentous, and myofascial. Three types of stretching techniques are generally recognized to facilitate musculotendinous flexibility: ballistic, static, and PNF.
Ballistic stretching consists of repetitive bouncing movements that stretch a muscle group. Ballistic stretching has not been advocated because forces could be applied to a muscle that exceed its extensibility or that activate the muscle spindles described previously, with resultant microtrauma to the muscle fibers. However, it has been reported that because many physical activities involve dynamic movement, ballistic stretching should follow a static stretching routine. Static stretching involves stretching a muscle to a point of discomfort and holding the stretch for a length of time, followed by a return to normal resting muscle length.
PNF involves alternating muscle contractions and stretching. The efficacy of all three techniques has been evaluated, and it appears that each technique has the capacity to increase flexibility, with static stretching being the safest of the three. In some cases static stretching has been advocated over PNF because it is easier to teach and perform.
Some clinicians prefer PNF stretching because it allows stretching to occur in functional planes of movement that more closely simulate activities. Each of the techniques should be performed with a prescribed set of repetitions while taking care to avoid overstretching. Contraindications to general stretching are indicated in Box Evidence of an acute inflammatory or infectious process heat and swelling in or around joints.
Contractures or shortened soft tissues providing increased joint stability in lieu of normal structural stability or muscle strength. Contractures or shortened soft tissues forming the basis for increased functional abilities, particularly in individuals with paralysis or severe muscle weakness. Various mechanical passive and active assisted techniques augment manual passive stretching.
Methods of achieving the desired outcome are often limited only by creativity and improvisational skills. After the soft tissue restriction has been assessed, the clinician should analyze appropriate and effective ways of carrying out the treatment and rehabilitation plan. Several methods of stretching can be used, but a clinician should be careful to consider joint positioning when assessing extensibility and use standardized and consistent approaches to most accurately reflect reliable and valid measurements.
This technique has been described in detail by Travell and Simons. The rationale for a prolonged-duration, low-load stretch has been discussed. Figure illustrates a method of prolonged weighted stretching for the knee in which a small cuff weight is placed distally on the lower part of the leg to provide gentle passive stretching of the hamstring muscle group.
Similar types of stretches can be performed for the upper extremity, as seen in Figure The key to success with prolonged-duration, low-load types of stretches is to allow muscle relaxation and gentle overpressure.
If not comfortable, an athlete will contract the muscles surrounding the joint and resist the overpressure, which results in no short- or long-term gains in flexibility. These appliances aid in gaining and maintaining end range of motion.
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