Stretching is a form of
physical exercise
Exercise is a body activity that enhances or maintains physical fitness and overall health and wellness.
It is performed for various reasons, to aid growth and improve strength, develop muscles and the cardiovascular system, hone athletic ...
in which a specific
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
or
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
(or muscle group) is deliberately flexed or stretched in order to improve the muscle's felt
elasticity
Elasticity often refers to:
*Elasticity (physics), continuum mechanics of bodies that deform reversibly under stress
Elasticity may also refer to:
Information technology
* Elasticity (data store), the flexibility of the data model and the cl ...
and achieve comfortable
muscle tone
In physiology, medicine, and anatomy, muscle tone (residual muscle tension or tonus) is the continuous and passive partial muscle contraction, contraction of the muscles, or the muscle's resistance to passive stretch during resting state.O’Sull ...
. The result is a feeling of increased muscle control, flexibility, and range of motion. Stretching is also used
therapeutically to alleviate
cramps
A cramp is a sudden, involuntary, painful skeletal muscle contraction or overshortening associated with electrical activity; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the aff ...
and to improve function in daily activities by increasing range of motion.
In its most basic form, stretching is a natural and
instinctive
Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing both innate (inborn) and learned elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a v ...
activity; it is performed by
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s and many other
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s. It can be accompanied by
yawn
A yawn is a reflex lasting 4-7 seconds, and is characterized by a long inspiratory phase with gradual mouth gaping, followed by a brief climax (or acme) with muscle stretching, and a rapid expiratory phase with muscle relaxation. For fish an ...
ing. Stretching often occurs instinctively after waking from
sleep
Sleep is a sedentary state of mind and body. It is characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and reduced interactions with surroundings. It is distinguished from wakefulness by a de ...
, after long periods of inactivity, or after exiting confined spaces and areas. Not only
vertebrates
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
(mammals and birds), but also
spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...
s were found to exhibit stretching in 2021.
Increasing flexibility through stretching is one of the basic tenets of
physical fitness
Physical fitness is a state of health and well-being and, more specifically, the ability to perform aspects of Outline of sports, sports, occupations and daily activities. Physical fitness is generally achieved through proper nutrition, moderate ...
. It is common for athletes to stretch before (for
warming up
'Warming up' is a part of stretching and preparation for physical exertion or a performance by exercising or practicing gently beforehand, usually undertaken before a performance or practice. Athletes, singers, actors and others warm up before s ...
) and after exercise in an attempt to reduce risk of injury and increase performance.
Stretching can be dangerous when performed incorrectly. There are many techniques for stretching in general, but depending on which muscle group is being stretched, some techniques may be ineffective or detrimental, even to the point of causing
hypermobility, instability, or permanent damage to the
tendons
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
,
ligaments
A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the:
* Peritoneal li ...
, and
muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
fiber.
The physiological nature of stretching and theories about the effect of various techniques are therefore subject to heavy inquiry.
Though static stretching is a part of some pre and post-workout routines, a review article that was published in January 2020 by the Scandinavian Society of Clinical Physiology and Nuclear Medicine, indicated that pre-exercise static stretching did in-fact reduce an individual's overall muscular strength and maximal performance. Furthermore, these findings present a uniform effect, regardless of an individual's age, sex, or training status. For this reason, an active dynamic warm-up is recommended before exercise in place of static stretching.
Physiology
Studies have shed light on the function, in stretching, of a large
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
within the
myofibrils
A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. Each myofibr ...
of skeletal muscles named
titin
Titin (contraction for Titan protein) (also called connectin) is a protein that in humans is encoded by the ''TTN'' gene. Titin is a giant protein, greater than 1 µm in length, that functions as a molecular spring that is responsible for t ...
. A study performed by Magid and Law demonstrated that the origin of passive muscle tension (which occurs during stretching) is actually within the
myofibrils
A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. Each myofibr ...
, not extracellularly as had previously been supposed. Due to neurological safeguards against injury such as the
Golgi tendon reflex The Golgi tendon reflex
(also called inverse stretch reflex, autogenic inhibition, tendon reflex)
is an inhibitory effect on the muscle resulting from the muscle tension stimulating Golgi tendon organs (GTO) of the muscle, and hence it is self-indu ...
, it is normally impossible for adults to stretch most muscle groups to their fullest length without training due to the activation of muscle antagonists as the muscle reaches the limit of its normal range of motion.
Types of stretches
Stretches can be either static or dynamic, where static stretches are performed while stationary and dynamic stretches involve movement of the muscle during the stretch. Stretches can also be
active
Active may refer to:
Music
* ''Active'' (album), a 1992 album by Casiopea
* Active Records, a record label
Ships
* ''Active'' (ship), several commercial ships by that name
* HMS ''Active'', the name of various ships of the British Royal ...
or passive, where active stretches use internal forces generated by the body to perform a stretch and passive stretches involve forces from external objects or people to perform the stretch. Stretches can involve both passive and active components.
File:Suarez stretch.JPG, Football player Luis Suárez
Luis Alberto Suárez Díaz (; born 24 January 1987) is a Uruguayan professional footballer who plays as a striker for Uruguayan Primera División club Nacional and the Uruguay national team. Nicknamed ''El Pistolero'' ('The Gunman'), he is ...
stretching prior to a match.
File:This Is How We Stretch (2364465748).jpg, Martin Brodeur
Martin Pierre Brodeur (; born May 6, 1972) is a Canadian-American former professional ice hockey goaltender and current team executive. He played 22 seasons in the National Hockey League (NHL), 21 of them for the New Jersey Devils, with whom ...
stretching on the Devils' bench during warmups.
File:Bishop Loughlin Games - Armory - Track & Field (11609407975).jpg, Assisted stretching may be performed when the athlete is unable to stretch optimally independently. For example, during cramping of the hamstrings, assistance in stretching out the muscles may help.
File:Fb1.jpg, Yoga Asana
An asana is a body posture, originally and still a general term for a sitting meditation pose,Verse 46, chapter II, "Patanjali Yoga sutras" by Swami Prabhavananda, published by the Sri Ramakrishna Math p. 111 and later extended in hatha yoga ...
stretching
Dynamic stretching
Dynamic stretching is a movement-based stretch aimed at increasing blood flow throughout the body while also loosening up the muscle fibers. Standard dynamic stretches typically involve slow and controlled active contraction of muscles. An example of such a dynamic stretch is lunges. Another form of dynamic stretching is ballistic stretching, which is an active stretch that involves bouncing or swinging back and forth at a high speed in order to take a muscle beyond its typical range of motion using momentum. Ballistic stretching can also be performed with tools such as resistance bands to increase the intention between sets in order to quickly warm-up the body. Ballistic stretching may cause damage to the joints.
Static stretching
The simplest static stretches are static-passive stretches, according to research findings. This brings the joint to its end range of motion and hold it there using external forces. There are more advanced forms of static stretching, such as proprioceptive neuromuscular facilitation (PNF), which involves both active muscle contractions and passive external forces.
PNF stretching may involve contracting either the antagonist muscles, agonist muscles, or both (CRAC).
Effectiveness
![06 12 08 Roller Dolls 003](https://upload.wikimedia.org/wikipedia/commons/d/d4/06_12_08_Roller_Dolls_003.jpg)
Stretching has been found both effective and ineffective based on its application for treatment.
Although many people engage in stretching before or after exercise, the
medical evidence has shown this has no meaningful benefit in preventing specifically muscle soreness. It may reduce the lactic acid build up in the muscles, making the next workout more bearable.
Stretching does not appear to reduce the risk of injury during exercises, except perhaps for runners.
There is some evidence that pre-exercise stretching may increase athletes' range of movement.
[ Also studies highlight that a structured calf stretching programme increases ankle joint dorsiflexion showing that these type of stretching exercises can be employed for first line conservative management of ankle equinus.
There are different positives and negatives for the two main types of stretching: static and dynamic. Static stretching is better at creating a more intense stretch because it is able to isolate a muscle group better. But this intensity of stretching may hinder one's athletic performance because the muscle is being overstretched while held in this position and, once the tension is released, the muscle will tend to tighten up and may actually become weaker than it was previously. Also, the longer the duration of static stretching, the more exhausted the muscle becomes. This type of stretching has been shown to have negative results on athletic performance within the categories of power and speed. However, to be able to do usual daily activities, a certain amount of range of motion is needed from each muscle. For example, the calf muscles are one of the muscle groups that have the most need for adequate flexibility since they are deeply related to normal lower limb function. When the goal is to increase flexibility, the most commonly used technique is stretching. Chronic static stretching was shown to increase range of motion of ]Dorsiflexion
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...
or bringing one's foot closer to their shin by an average of 5.17 degrees in healthy individuals versus 3.77 degrees when solely using ballistic stretching.
Still, ballistic stretching is likely to increase flexibility through a neurological mechanism. The stretched muscle is moved passively to the end range by an external force or agonist muscle: holding a muscle in this position might reduce muscle spindle sensitivity, with repeated stretch applied at the end range inhibiting the GTO.
Dynamic stretching, because it is movement-based, may not isolate the muscle group as well or have as intense of a stretch, but it is better at increasing the circulation of blood flow throughout the body, which in turn increases the amount of oxygen able to be used for athletic performance. This type of stretching has shown better results on athletic performances of power and speed when compared to static stretching.
However, both of these types of stretching have been shown to have a positive impact on flexibility over time by increasing muscle and joint elasticity, thus increasing the depth and range of motion an athlete is able to reach. This is evident in the experiment "Acute effects of duration on sprint performance of adolescent football players". In this experiment, football players were put through different stretching durations of static and dynamic stretching to test their effects. They were tested on maximum sprinting ability and overall change in flexibility. Both static and dynamic stretching had a positive impact on flexibility but, whereas dynamic stretching had no impact on sprint times, static stretching had a negative result, worsening the time the participants were able to sprint the distance in.
Stretching tools
* BOSU
A BOSU Balance Trainer (or BOSU ball) is a fitness training device, invented in 1999 by David Weck. It consists of an inflated rubber Sphere, hemisphere attached to a rigid platform. The device is often used for Balance (ability), balance trainin ...
* Flexcushion
* Foam roller
* Stretch Band
References
* Iatridou, G., Dionyssiotis, Y., Papathanasiou, J., Kapetanakis, S., & Galitsanos, S. (October/December 2018)
"Acute effects of stretching duration on sprint performance of adolescent football players"
''Muscles, Ligaments & Tendons Journal'' (MLTJ), 8 (4), 37–42. .
Further reading
*
* Anderson, Bob (2010).
Stretching: 30th Anniversary Edition
'. Shelter Publications.
*
*
* Shrier, Ian (2005)
"When and Whom to Stretch?"
''The Physician and Sportsmedicine'' 33 (3): 22–26. .
External links
*
{{Authority control
Stretching