Lengthening muscles not good from evolutional perspective? Why do we do it with explicit stretching?

Lengthening muscles not good from evolutional perspective? Why do we do it with explicit stretching?

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Stretching has many advantages, among other things it helps us to be flexible in our movement (which is an advantage?!).

But why do we need to actively stretch, it seems that the body wants to shorten the muscles by evolution (e.g. when training often in fitness studio). This is the opposite of what we do when stretching.

It seems to be that there are advantages of being not stretched. So what are these advantages / what is the evolutional rationale?

Edit: Why this question is different from this question:

That question asks, why we automatically stretch sometimes after e.g. sleep. The answer is that we stretch the soft tissues because of transitions of high and low activities (especially after sleep, in which we ease the tension in our muscles [muscular antonia]).

This question asks something different. It asks about explicit stretching in sports and not about automatically stretching behavior. The aim is different. In sports we stretch because, we want to lengthen our muscular. The question is why lengthening doesn't seem to be a good thing from an evolutional perspective.

Edit 2: I'm not sure, if it is clear for everybody, what I mean, so I add a succinct example: Why would it be bad (evolutional rationale), if everybody could do a split (gymnastics) by nature (disadvantages?)? In our reality, the ability to do this is almost always an result of stretching. This is only one extreme example, mostly people don't strech to such extremes. Maybe this now helps to understand, for what this question heads.

Muscles only ever work by shortening, as you say, but muscles in the human body tend to be found in antagonistic pairs. These pairs of muscles act in opposite directions, one example being the biceps and triceps muscles - the biceps bends the arm (a flexor muscle) while the triceps straightens the arm (an extensor muscle), another example is the quadriceps-hamstring muscle pair in the upper leg.

If our muscles remained shortened, our mobility would be impaired. If the biceps muscle remained too short, it would be impossible to extend our arms, for example. Muscles do work by shortening, yes, but it's important for them to be able to stretch as well, and remain long enough for antagonistic muscles to have their full movement be possible as well.


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Lamarckism, a theory of evolution based on the principle that physical changes in organisms during their lifetime—such as greater development of an organ or a part through increased use—could be transmitted to their offspring. The doctrine, proposed by the French naturalist Jean-Baptiste Lamarck in 1809, influenced evolutionary thought through most of the 19th century. Lamarckism was discredited by most geneticists after the 1930s, but certain of its ideas continued to be held in the Soviet Union into the mid-20th century.

The Physiology Of Muscle Growth

After you workout, your body repairs or replaces damaged muscle fibers through a cellular process where it fuses muscle fibers together to form new muscle protein strands or myofibrils. These repaired myofibrils increase in thickness and number to create muscle hypertrophy (growth). 1 Muscle growth occurs whenever the rate of muscle protein synthesis is greater than the rate of muscle protein breakdown. This adaption, however, does not happen while you actually lift the weights. Instead, it occurs while you rest.

So how do you actually add muscle to your muscle cells? This is where Satellite cells come in and act like stem cells for your muscles. When activated, they help to add more nuclei to the muscle cells and therefore contribute directly to the growth of myofibrils (muscle cells). Activating these satellite cells may be the difference between what allows certain “genetic freaks” to grow massive muscles and what makes other people “hard-gainers. 2 ”

In one of the most interesting studies in the past 5 years, researchers showed that those who were “extreme responders” to muscle growth, with an incredible 58% myofiber hypertrophy from an exercise, had 23% activation of their satellite cells. Modest responders, who had a 28% growth, had 19% activation of their satellite cells. What is interesting to note, though, is that some people known as “non-responders” in the study had 0% growth and had a concurrent 0% activation of their satellite cells. Therefore, it seems the more you can activate these satellite cells, the more you’ll be able to grow. So then the question becomes, how do you activate these satellite cells to increase muscle growth?


General CommentThis is one of Tool's most amazing songs, and really sums up the entire theme of Aenima. This song is about growing, changing, and moving towards the next level of human evolution and conciousness. It's deeply rooted in Jungian theory.

Basically, it's believed that there are three levels of human evolution and each has it's form of conciousness. There's the 1st level with 44 chromosones. These are primitve people's like the aboriginies in Australia who do not percieve anything outside of themselves. They only see one large conciousness with no distinguishment between organisms. Then there's the second level with 46 chromosones. That is us. We are a chaotic disharmonic conciousness that is basically used as a stepping stone between the first and third levels. The third level is 48 chromosones. (Or 46 & 2, with 2 being the sex chromosones x & y). This is the higher level of conciousness. Our destination.

But this is where the Jungian theory comes in. It is believed that you can not reach this third level of evolution without first delving into yourself and basically cleansing your conciousness for the next jump. That's where the Shadow comes in. The shadow is basically everything about that is unseen that you are uncomfortable with or hate. This is also known as the Anima (hence the name of the CD).

The last part of the song sums all of this up.

"See my shadow changing,
Stretching up and over me
Soften this old armor
Hoping I can clear the way
By stepping through my shadow,
Coming out the other side
Step into the shadow
Forty six and two are just ahead of me"

Apes have 48 chromosomes, as do potatos. Australian aboriginies have 46 like all other humans

the spicie with the most chromosomes is Ophioglossum(a plant) with 1,400 chromosomes.

Love the song. love tool but Mr Carl Jung just had too many acids. lol

We can't blame Oberones for coming up with the theory but we can blame him for presenting such shit, racist at that, as truth.

Spreading misinformation is despicable.

Did anyone every stop to think that Maynards twisted mind is so twisted that he would write a simple song so that everyone would misinterpret it?
Has anyone ever thought that its about football?
Well its would be funny if it were so simple.
But again someone says that this 0berones is correct.
In an interview where Danny Carey spoke with a reporter from Slamm magazine it states:

SLAMM: You mentioned the importance of evolution as it relates to the
band. "Forty-six & 2" off the new album seems to address this theme,
correct? And what does "Forty-six & 2" mean?

Danny: "Forty-six & 2" is a DNA chromosome count. And in the song we
use it as a metaphor for evolution and change. Right now, humans have
forty-four plus two, and supposedly the next step in our evolution
will be the addition of a couple more chromosomes. -end-

I find this amusing that there are so many comments about tool lyrics.
because Danny also stated that:

Danny: In our method of composing, Maynard is singing in the room
with us, but he's not really singing words. The words are an
afterthought. And the words and lyrics are about 90% Maynard's
interpretation. We don't place that much significance on them. We want
people to interpret the music and get their own inspiration out of it.
That's what we hope for, anyway. That's why we don't put the words in
the record, either, because people will latch onto them heavily. If
words were so important, compared to the light and energy that is
going on the stage, then people would be selling out spoken word
shows. Which they aren't. The music is what the emphasis is on in our

First off. Aboriginals is a modern term. think of it not so much as just Australians, but lesser evolved people of the past (those with 44). Dont get hung up on human made labels. Think outside the label.

And on that note of thinking outside the box.
Let me share an observation and question inspired by TaintedDeity's rebuttle.

Jungian theory stresses that people focus too heavily on science and not enough on spirituallity (label it what you may but dont think religiously here).

This is just one out of millions of examples of people relying on scientific theory that is supposedly holding us back according to Jung.

How do we know he is not right?

I am a Anthropology/Philosophy double major right now if it helps for me to qualify myself.

I realize this is fourteen years too late, but for the sake of anyone looking into the meaning behind the lyrics to one of TOOL's most arcane masterpieces, please take note:

Carl Jung != Drunvalo Melchizedek

The title of 46&2 and all the explanations you'll come across regarding chromosomal compositions and their supposed relation to the evolution of consciousness are originating from Melchizedek's books and teachings, not "the Jungian theory."

The only EXPLICIT reference to Jungian concepts in this song is where the narrator makes repeated references to his "shadow."

This is not the first time I've seen this online. Interpretations are fine, but please don't attribute this lunatic-fringe chromosome stuff to someone as amazing as Carl Gustav Jung.

My Interpretation"Everyone carries a shadow, and the less it is embodied in the individual's conscious life, the blacker and denser it is. It may be (in part) one's link to more primitive animal instincts, which are superseded during early childhood by the conscious mind." - Jung

The song is about Jung's Psychological theory of the "Shadow."

And yes, it does have something to do with Chromosomes- Jung said that it is "One's link to more primitive animal instincts.." Humans have 46 chromosomes. Apes have 48.
46 + 2 = 48

I like that interpretation of the song. I also see a third reference of the Bible verse Psalm 46:2. The Album's CD case has the image off California being destroyed by earthquakes and flooding. Psalm 46:2 reads:

2 Therefore will not we fear, though the earth be removed, and though the mountains be carried into the midst of the sea.

General CommentThis song is so awesome and powerful I don't even have words to describe it.

I was just thinking one thing could the whole shadow story be, among the other stuff, even a reference to the first verse of Sober? I like to think that when in Sober the protagonist of the song was chased by this negative (his own?) shadow, in Forty Six and Two he finally evolves, he get over his misery and he's free of his old shadow.

My Interpretation[This song is about self improvement]

My shadow's
Shedding skin and [he sees himself as frayed and in a state of loss]
I've been picking
Scabs again. [He knows he has been the cause of it- doing it to himself]

I'm down [he is deeply..]
Digging through [searching his inner self]
My old muscles [of his fundamental makeup (habits/interest/hates)]
Looking for a clue. [of what is causing this]

I've been crawling on my belly [he has left nothing unexamined]
Clearing out what could've been. [busily discarding haunting what-ifs]
I've been wallowing in my own confused [everywhere he digs he finds ]
And insecure delusions [the what-ifs and lies to self that are -------------------------------------------------------------[truly not needed]

For a piece to cross me over [he hopes for an easy fix]
Or a word to guide me in. [or the guidance to fix himself]
I wanna feel the changes coming down. [he truly wants to get better]
I wanna know what I've been hiding in [and identify the hidden source of his -------------------------------------------------------------[problems]

My shadow. [he identifies his Shadow as the inner self- his ------------------------------------------------[core being, or Soul]
Change is coming through my shadow. [he knows that to fix himself he must mend his Soul.
My shadow's shedding skin [he sees that his soul is suffering]
I've been picking
My scabs again. [and that he was the cause of it all]

I've been crawling on my belly [he continues to examine himself, knowing
Clearing out what could've been. [now what he has learned]
I've been wallowing in my own chaotic
And insecure delusions.

I wanna feel the change consume me, [he knows to truly change will devour all ----------------------------------------------------------[that he was- and get rid of it]
Feel the outside turning in. [he wants his outer self to change along with ---------------------------------------------------[his inner self]
I wanna feel the metamorphosis and [he wants the change all through him]
Cleansing I've endured within [that he has started to repair in His -----------------------------------------------------------------Shadow]

My shadow
Change is coming. [its working!]
Now is my time.

Listen to my muscle memory. [in his new self construction, he looks -------------------------------------------------------------back with hindsight]
Contemplate what I've been clinging to. [on his foolish beliefs/delusions]
Forty-six and two ahead of me. [there were 46 cycles of refining the list ------------------------------------------------------------of what to keep, and 2 left to do]

I choose to live and to
Grow, take and give and to
Move, learn and love and to
Cry, kill and die and to [This is self correction #45- the aspects he has chosen to hold onto]
Be paranoid and to [There are 14 at this point]
Lie, hate and fear and to
Do what it takes to move through. [do it again (divide the list in half)]

I choose to live and to
Lie, kill and give and to [This is correction #46- the refined list of what
Die, learn and love and to [he chooses to retain in his core being. 7 left]
Do what it takes to step through. [do it again (divide the list in half)]

See my shadow changing, [see how it works?]
Stretching up and over me. [the Shadow is more whole than it has been]
Soften this old armor. [his old defenses really arent needed anymore]
Hoping I can clear the way [to finish he must FINISH]
By stepping through my shadow,[each pass through his shadow is another turn]
Coming out the other side. [what emerges is the new self/list]
Step into the shadow. [do it again-]
Forty six and two are just ahead of me.
[he has done it 46 times, and 2 more remain]

So, he has learned how to improve himself, and we are hearing if his process between the 46th and 47th repeat

He lists his previous "insecure delusions" of 14, and whittles it down to 7, keeping only those he wishes to. He must do it 2 more times, leaving him with 1.7 aspects (1 fully, another just mostly) he wishes to hold onto at the end- that which he holds MOST important in his being.

So its not anything bad, nor violent. Its just ruthless self examination and improvement, performed whenever he notices his shadow looking a little rough.

Mechanics and neuromechanics as the common ground between biological and robotic systems

The fields of biological and robotic behavior are, fortunate in that principles of mechanics are at the root of both evolutionary biology and robotics. Darwinian evolution and Newtonian mechanics are unforgiving arbiters that continually shape what is possible and successful in the physical world. Thus, even though animals have had to evolve whereas robots have had to be designed and built, both had to successfully withstand and exploit the laws of mechanics [54]. Therefore, studying biological systems in the context of the physical function of grasp and manipulation does have the possibility of providing insights into how the structure of the body, information processing in the nervous system, and their interactions give rise to complex behavior.

An appropriate name for this approach is Neuromechanics. To our knowledge, this term was first coined by Enoka in his 1988 book Neuromechanical Basis of Kinesiology [69]. We use the term neuromechanics as describing the functional co-adaptations of the nervous, motor, sensory and musculoskeletal systems to produce effective and versatile mechanical behavior with a physical body in the physical world. In a field that mostly emphasizes the cognitive capabilities of the mammalian brain, it is easy to overlook that the nervous system and body co-evolved well before mammals appeared [70]. Thus, there is much to be learned when studying neural function using physical behavior by the periphery (i.e., limbs) as a means to understand central (i.e., neural) function [54]. But how can we move away from the difficulties in deductive inference mentioned in the prior section?

One promising approach is to use synthetic analysis to build neuromorphic neuromechanical systems that exploit physical reality as the common ground between biological and robotic systems. The neuromorphic approach reflects the sentiment expressed by Richard Feynman, ‘What I cannot build I do not understand. Know how to solve every problem that has been solved.’ 3 In our context, it can be taken to mean that, if we have over one hundred years of sensorimotor neuroscience since Sir Charles Sherrington [71], and if the principles we have deduced are sound, then we should be able to build components that embody those mechanisms in such a way that when assembled they behave like biological systems [72, 73]. One example of such a neuromorphic approach uses ultra-fast computer processors to simultaneously implement populations of autonomous, interconnected spiking neurons in real time that follow Hodgkin-Huxley rules of how action potentials in neurons are initiated and propagated [74]. As mentioned in [72, 75], this general approach has also been successfully applied to understand mechanisms of memory, visual representation, and cognitive function. Note that neuromorphic is distinct from neuromimetic or neuroinspired. Biomimetic (neuromimetic) and bioinspired (neuroinspired) work seeks to copy or replicate the biological (neural) behavior by any engineering means—like prosthetic hands that have no muscles or tendons, or airplanes that fly without flapping wings. In contrast, neuromorphic approaches use engineering means to implement the biological mechanisms themselves.

As explained in [72], we have taken this approach one step further by combining neuromorphic and neuromechanical approaches we seek to implement the neural control of the body—effectively merging biology and robotics in the arena of physical function. We have coupled real-time neuromorphic implementations of stretch reflex circuitry in populations of spinal neurons, to electric motors controlled by real-time models of muscle function to apply forces to the tendons of actual human cadaveric fingers. This is the first neuromorphic neuromechanical system, to our knowledge, that has put our understanding of fundamental sensorimotor mechanisms in the spinal cord to the ultimate test of physical implementation. Importantly, the behavior emerges from the system as it is not prescribed beyond the nature and connectivity of its elements. An added advantage is that one can also ‘record’ from single or multiple neurons, motor units, afferent nerves, etc. to explore emergent behavior at truly multiple scales. So far, this approach has allowed us to begin to understand cardinal features of afferented muscles of human fingers to replicate fundamental features of healthy muscle tone, hypo and hypertonia [73].

While still an imperfect approximation, this neo-Sherringtonian approach helps us test arguments about which specific features of spiking neurons and their connectivity, spindle function, fusimotor drive, descending commands, finger anatomy and tendon/skin/joint tissue properties suffice to produce realistic healthy and pathologic behavior in afferented muscles acting on anatomical fingers. Moreover, this has the advantage of using physical behavior as the ground truth for the evaluation of functional performance.

A combined neuromorphic and neuromechanical approach, although grounded and developed for neuroscientific applications, could potentially inspire robotics research and design by revealing insights into how complex behaviors emerge from adaptation of neural controllers to mechanical properties of physical systems.

The Common Compensatory Pattern: Its Origin and Relationship to the Postural Model, 2003

J. Gordon Zink, DO1 was the originator of the term Common Compensatory Pattern (CCP). He used the term to describe commonly found patterns of dysfunction in the body (neuromyofascial-skeletal unit) as a whole. Several other physicians before and since, have also described recurring patterns of dysfunction found in their patient populations. Dr. Zink, however, is considered to be “… the first to provide a written, understandable, and clinically useful explanation for treatment, with a method of diagnosing and manipulative methods of treating the fascial patterns of the body.” Zink himself considered these concepts to be the basis of a respiratory and circulatory care model.

As osteopathic clinicians we frequently find recurrent patterns of fascial bias, postural asymmetry, somatic dysfunction, and functional disturbances. We frequently see a clinically short right leg, a cephalad pubes dysfunction on the left, a posterior ilium on the left and an anterior ilium on the right. Patients regularly display a left on left sacral torsion with L-5, side bent left and rotated right as well. These are just a few of many commonly found somatic dysfunctions the list is long. Radiographically, with our patients’ postural studies, we can find recurring patterns of postural asymmetry that includes the anatomic short right leg and a sacral base declination to the right with compensatory rotoscoliosis. Beyond these findings we have recurrent patterns of functional disturbance such as muscle imbalance and visceral dysfunction, coupled with common systemic complaints.

Why do we see these same patterns over and over again? Is there a linkage between all of these commonly found clinical phenomena? Further, what is the clinical significance of these patterns? There appears to be an inherent fascial bias found in most people. There also appears to be a causal linkage between fascial bias and subsequent growth of the individual. Could these governing factors explain recurrent patterns of postural asymmetry that we find in the postural model? The probable key to these questions and their answers reside in the fascia.

New Mechanism of Muscle Force Production

As outlined above, actively stretched myofibrils have vastly increased forces compared with passively stretched myofibrils in the absence of actin-myosin filament overlap, and thus in the absence of cross-bridge-based forces. It has been demonstrated that at least part of this increased force is associated with a passive structural element of muscle and, furthermore, that elimination of titin in single myofibrils abolishes all force transmission across sarcomeres (55) and all residual and passive force enhancement (49). These observations led to the idea that titin is a molecular spring that increases its stiffness, and thus its force, in active compared with passive muscle contraction. There are two basic ways in which a molecular spring, like titin, might increase its stiffness: 1) by increasing its inherent spring stiffness and/or 2) by shortening its spring length. In the following, we will consider these two possibilities.


GM muscle's maximum ACSA (ACSAmax), Vol, Lf, θ, and PCSA of the elderly and young adult populations are presented in Table 1. All the investigated muscle architectural parameters were reduced in the elderly compared with the younger adults.

Table 1. Summary of gastrocnemius medialis architectural data in young and elderly individuals

Values are means ± SD n = 14 for the young (27-42 yr) group and n = 16 for the elderly (70-81 yr) group. ACSAmax, maximum anatomic cross-sectional area Vol, muscle volume Lf, fascicle length θ, pennation angle PCSA, physiological cross-sectional area.

The differences between the elderly and younger groups were 19.1% (P < 0.005) for ACSAmax, 25.3% (P < 0.001) for Vol, 10.2% (P < 0.01) for Lf, 13.2% (P < 0.01) for θ, and 15.2% (P < 0.05) for PCSA. When θ was plotted against ACSA (Fig. 1), and the experimental data points were fitted with a linear function, a significant correlation (r = 0.432, P < 0.05) was found between the two variables, indicating that θ scales with ACSAmax. Also, it is noteworthy that in most elderly individuals values of both ACSAmax and θ were smaller than in the younger adults.

Fig. 1.Individual data of maximum anatomic cross-sectional area (ACSA) plotted against pennation angle for the young adults (•) and elderly individuals (○). Data are fitted with a linear regression function after the values for the young and elderly subjects were pooled together.

Although the difference in ACSAmax seemed greater than that of PCSA (Table 1), no significant difference was found between the ratios of ACSAmax to PCSA of the young (0.30 ± 0.04) and those of the elderly subjects (0.29 ± 0.06, not significant). When the values of ACSAsmax and PCSAs of the young and elderly subjects were pooled together, a significant correlation (r = 0.759, P < 0.01) was found between ACSAmax and PCSA (see Fig. 2).

Fig. 2.Typical sonographs of the gastrocnemius medialis muscle of an elderly man (A) and of a young man (B).

How much physical activity is enough?

It is apparent that physical activity is essential in the prevention of chronic disease and premature death. 14 However, doubt remains over the optimal “volume” (frequency, duration and intensity of exercise) and the minimum volume for health benefits, in particular the effects of intensity (e.g., moderate v. vigorous) on health status. There is evidence that intensity of physical activity is inversely and linearly associated with mortality. 14 Early work by Paffenbarger and associates 106 revealed that regular physical activity (expending > 2000 kcal � kJ] per week) was associated with an average increase in life expectancy of 1 to 2 years by the age of 80 and that the benefits were linear even at lower levels of energy expenditure. Subsequent studies have shown that an average energy expenditure of about 1000 kcal (4200 kJ) per week is associated with a 20%�% reduction in all-cause mortality. 14 , 106 , 107 Currently, most health and fitness organizations and professionals advocate a minimum volume of exercise that expends 1000 kcal (4200 kJ) per week and acknowledge the added benefits of higher energy expenditures.

Recently, investigators have postulated that even lower levels of weekly energy expenditure may be associated with health benefits. 107� A volume of exercise that is about half of what is currently recommended may be sufficient, 14 particularly for people who are extremely deconditioned or are frail and elderly. 6 Future research is required to determine whether expending as little as 500 kcal (2100 kJ) per week offers health benefits. If so, then previously sedentary people may be more likely to engage in physical activity and maintain an active lifestyle.

The dose–response relation between physical activity and health status outlined above generally relates to cardiovascular disease and premature death from any cause. However, the same may hold true for other activity-associated health benefits. For instance, as mentioned earlier, moderately intense levels of exercise (≥ 5.5 METs for at least 40 minutes per week) and of cardiovascular fitness (> 31 mL oxygen per kilogram per minute) are effective preventive strategies against type 2 diabetes. 48 In patients with type 2 diabetes, walking more than 2 hours per week has also been shown to reduce the risk of premature death. 49

With respect to cancer, a review of the literature revealed that moderate physical activity (> 4.5 METs) for about 30� minutes per day had a greater protective effect against colon and breast cancer than activities of low intensity. 67 The greatest benefit for reducing the incidence of breast cancer was observed among women who engaged in 7 or more hours of moderate-to-vigorous activity per week. 110 Among patients with established cancer, physical activity equivalent to walking 1 or more hours per week was associated with improved survival compared with no exercise. 74 The greatest benefit was observed among cancer survivors who performed exercise equivalent to 3𠄵 hours per week at an average pace. 74

With respect to osteoporosis, the dose–response relation of physical activity is less clear. However, osteogenic adaptations appear to be load-dependent and site-specific. 9 , 10 , 111 Accordingly, physical activities that require impact or significant loading are therefore advocated for optimal bone health. Running distances of up to 15� miles (24� km) per week has been associated with the accrual or maintenance of bone mineral density, but longer distances may be associated with reduced bone mineral density. 112


Spontaneous mimicry appears fundamental to emotional perception and contagion, especially when it involves facial emotional expressions. Here we cover recent evidence on spontaneous mimicry from ethology, psychology and neuroscience, in non-human and human animals. We first consider how mimicry unfolds in non-human animals (particularly primates) and how it relates to emotional contagion. We focus on two forms of mimicry-related phenomena: facial mimicry and yawn contagion, which are largely conserved across mammals and useful to draw evolutionary scenarios. Next, we expand on the psychological evidence from humans that bears on current theoretical debates and also informs non-human animal research. Finally, we cover the neural bases of facial mimicry and yawn contagion. We move beyond the perception/expression/experience trichotomy and from the correlational to the causal evidence that links facial mimicry to emotional contagion by presenting evidence from neuroimaging, direct manipulation, neuro-stimulation and lesion studies. In conclusion, this review proposes a bottom-up, multidisciplinary approach to the study of spontaneous mimicry that accounts for the evolutionary continuity linking non-human and human animals.