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Theory & Practice: Athlete’s Muscles

I hear discussions of muscles and fibers and I wonder if people participating in the discussion are talking about doing something or is it a theoretical discussion of anatomy. If you’re studying anatomy or have scientific interest in the topic of muscles, tissues and fibers then it makes sense, but if you’re an athlete of any level or a coach – while it might satisfy some curiosity, it won’t serve practical purpose.

Types of ‘Knowing’

Within the context of athletics and training there are things we need and don’t need to know in a sense of practically useful information. It is human nature to want to know. However, just because we’re curious about various layers of muscles, it doesn’t mean we need to know, or that that type of knowing will be practically helpful for performing a specific task. As a matter of fact, certain types of information prevent people from seeing the big picture. It’s ok to amass information, but it is also important to not lose sight of the correct hierarchy of things.

Knowing various types of muscle fibers or singling out various muscle groups, their structure and their function will not make a practical difference and will not make you a better athlete. If you want to be better at running, throwing, jumping, lifting, swimming, etc – what you need to know is how to do it and what specific action(s) to take to make it happen.

Ego VS Body

Whether we want to acknowledge it or not, our body, our muscles “know” what they need to do and they do it. Our problems begin when we insist on controlling every aspect of our body moving in space and time. Add to that the fact that most people either have zero instruction or the wrong instructions on HOW to move and it is not difficult to see the potential mess we can get into.

While we think about what we assume our muscles should be doing in order to move our leg this way or that way, and we think of what muscles should be firing or working – our body and its constituent parts have already not only activated the necessary parts, but most likely have already finished the job, too. The speed of our thought, no matter how fast we assume we think, is a lot slower than any interaction that naturally goes on within a human body. So, unless it is your intent to slow yourself down, think only of the action that needs to happen to promote a particular task at hand, i.e. if you want to run, think only of pulling your foot up to change support. The rest of the elements of a particular athletic activity should be worked on and brought to the level of autopilot in training sessions.

‘Big Picture’ Hierarchy

The most logical place to start the hierarchy of movement is our environment. Our movement is not a random and independent twitching of muscle fibers. Our whole body is at the mercy of natural forces that make up our world and are ruled by gravity. It holds everything together. Gravity is the starting point.

Gravity gives us bodyweight. No gravity -> no bodyweight -> no movement. Gravity less than on Earth -> same body different weight -> dramatic changes in basic movement (Ex.: running turns into hopping)

Dr. Nicholas Romanov, founder of the Pose Method, demonstrates how our active muscle efforts are useless without the presence of body weight. How do you use your muscles when running? Have you ever been told to “fire your glutes”? In this video, watch how your muscles can be rendered useless when you can’t apply your body weight.

Muscles’ Purpose

All muscles are equally important. We should not take our body apart – these muscles are for running, these fibers are for speed, these are for cycling, and these are for lifting, etc. This is not how it works. This confusion comes from lack of understanding of how our body operates. Each muscle and muscle group perform their own important function, and, as we can see, they are all connected. All muscles work in sync. The synchronization includes the entire body and extends all the way to our heartbeat.

Now let’s zoom out to see the big picture. Muscles, along with tendons and ligaments, hold the whole body together and provide an intricate network of mechanisms that allow movement. ‘Allow’ is the keyword. Without our bodyweight, the same network of muscles still provides the same mechanisms yet movement either does not happen at all, or looks very differently.

As far as movement is concerned, our muscles mean nothing without our bodyweight. Muscles do not create or initiate movement. Muscles play the supporting role.

 

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About the Author

Dr. Nicholas Romanov is the developer of the Pose Method®. A passionate proponent of higher level of education in athletics, Dr. Romanov dedicated his entire career to sports education, scientific research and coaching. An Olympic Coach and a bestselling author, Dr. Romanov has taught on all continents and visited almost every country in the world.
[ Click here to learn more ]

CONTINUING EDUCATION + LIVE SEMINARS + LOCAL CLASSES

Pose Method® 2-Day Educational Seminar is approved for 16 contact hours towards continuing education for Certified CrossFit Trainers and Physical Therapists. Athletes and parents of school age children are encouraged to attend.

The Pose Method® system is a combination of online learning, live seminars and local classes making it the most effective solution available to health and fitness professionals as well as anyone who enjoys an active lifestyle.

Technique: How High to Pull Your Foot Up When Running?

How high should you pull your foot up when running and with how much effort? To know the answer to this question, one has to understand the purpose of the action of pulling your foot up when running. This is where the importance of understanding the ‘why’ is highlighted again. Reading the theory and understanding it through and through is not about complicating what most of us wish was such a natural form of locomotion – running. Contrary to that common assumption and in my opinion, gaining full understanding of the subject is actually about gaining freedom. Freedom to effortlessly do what needs to be done because you know exactly what is happening, you know the rules and you can work with them at any speed on any terrain.

Required Height

To put it simply, the necessary height of the pull will sort itself out. You do not need to think about it, all you need to do is make a slight effort to pull your foot up high enough to clear the ground and so it allows for change of support because running is nothing but ‘change of support’ while falling forward. In the Pose Method of Running, the pull is the last element of the technique that allows for the most efficient transition from one foot to the other. All you need is to execute the action of pulling correctly – everything else will be done for you. Trust the natural forces.

Minimal Effort

Effortless running is achieved through biomechanically proper technique because such technique works with and uses the natural forces such as gravity. By its very definition, effortless running requires or should take less effort. So, if all we need to do is change support in order to run, then the ultimate goal is to do that action with the least possible effort. Narrowing down all required action to a single action of pulling in the Pose Method of Running gets us closer to running with less effort, and actively working just one group of muscles – the hamstrings – fits the purpose and serves it well.

You will notice that putting less intentional effort into pulling your feet up by utilizing the hamstrings only, will help you do it correctly. You will also notice that such an important thing as high cadence is easier to achieve, if you don’t strain to pull your feet all the way up.

Putting less intentional effort into pulling your feet up by utilizing the hamstrings only, will help you do it correctly.

The general rule is – you’re better off pulling your foot up less than more. If you pull too high and/or too hard you will waste energy and will tire your hamstrings and might get injured. Think about the typical injury for sprinters – pulled hamstrings. Keep in mind, that the exaggerated motion of the pull, demonstrated in the running drills, is strictly for learning purposes, to help your body learn better patterns of movement required for running.

What about other muscles? Leave them alone. All you need is to do one action – pulling your feet up with your hamstrings – to set everything in the right motion with minimal effort.

Various Speeds

When you run faster, your foot will end up higher. I say ‘end up’ because you are not supposed to be putting any effort into pulling it higher or leaving it lower. That’s too much to think about especially in sprinting where everything happens way before you can think about it. If you’re thinking about it, you are already too late.

When you run faster, your foot will end up higher.

(This is happening on its own and due to the forces already in play, Bolt is NOT PUTTING EFFORT INTO PULLING his foot up this high.)

There is no need to put any effort into forcing your foot so high. The entire trajectory of your foot will determine itself based on your speed. All you have to do is focus on maintaining your running pose.

At a slower speed your feet will be noticeably and naturally lower. When jogging, your running might resemble shuffling. Your feet will be at their lowest height of the pull.

 

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About the Author

Dr. Nicholas Romanov is the developer of the Pose Method®. A passionate proponent of higher level of education in athletics, Dr. Romanov dedicated his entire career to sports education, scientific research and coaching. An Olympic Coach and a bestselling author, Dr. Romanov has taught on all continents and visited almost every country in the world.
[ Click here to learn more ]

CONTINUING EDUCATION + LIVE SEMINARS + LOCAL CLASSES

Pose Method® 2-Day Educational Seminar is approved for 16 contact hours towards continuing education for Certified CrossFit Trainers and Physical Therapists. Athletes and parents of school age children are encouraged to attend.

The Pose Method® system is a combination of online learning, live seminars and local classes making it the most effective solution available to health and fitness professionals as well as anyone who enjoys an active lifestyle.

Theory & Practice: The Role and Importance of a ‘Standard’

We use the word ‘standard’ on daily basis, we’re all very familiar with its meaning. Here’s a quick sample of the meaning given in a dictionary just so we’re on the same page:

standard |ˈstandərd|
noun
1 a level of quality or attainment
2 an idea or thing used as a measure, norm, or model in comparative evaluations: the wages are low by today’s standards | the system had become an industry standard.
• (standards) principles of conduct informed by notions of honor and decency: a decline in moral standards.
• a form of language that is widely accepted as the correct form.
• the prescribed weight of fine metal in gold or silver coins: the sterling standard for silver.
• a system by which the value of a currency is defined in terms of gold or silver or both.

 

 

 

Standard Exists Everywhere

A ‘standard’ is, basically, an approved and generally accepted model of something, a rule or principle that is used as a basis for judgment, an average or normal requirement, quality, quantity, level, grade, etc. When Apple develops their gadgets – they have a standard they follow. When car makers build their creations – they follow standards in car manufacturing.

There are standards being taught and displayed in all sports. Not all are necessarily correct, according to my understanding of movement and in my humble opinion, but there are standards nonetheless. In running, however, we are all suddenly unique and all have different techniques and styles. Does that not sound a bit strange? It does. And it is. Of course we are all unique individuals, but let’s not confuse our personalities and styles with technical standard in movement.

Benefits of Having a Standard

What does having a ‘standard’ offer us when it comes to human movement in sports, and in general?

  • Precise model to learn. With a standard model to learn, a student avoids the potential pitfalls of a wandering mind. Experimenting on top of a learned standard is quite different from experimenting without the basic foundation. While the first is full of advantageous discoveries, the latter is full of confusion and easily avoidable mistakes.
  • Precise model to teach. If there was no standard, all teachings or attempts to teach would be disorganized, scattered, unfocused, etc. There would be no way to determine what’s a mistake and what is not. There would be no way to offer clarity of the subject to a student. Teaching would be an impossible task.
  • Ability to identify and correct errors. This is probably one of the most important attributes of any model of any ‘standard’. When there is a clearly identified and put forth model for a standard, any deviation from that standard is easily seen. That is precisely the definition of an ‘error’. In order for something to be labeled an error there has to be a clear standard according to which something is classified as an error. One does not exist without the other.

The claim that there is no correct running technique or any other correct sports technique is unfounded and is not supported by science. Moreover it does not make any sense. Unless we figure out how to defy gravity or it suddenly changes the way it works – we will abide by its current standard of operation that has not changed since our planet came into being.

The laws of operation of all natural forces with gravity at the helm consequently lead to a particular set of rules in movement of a human body. This standard branches out into standards in human movement when participating in various athletic activities or simply moving around. Movement related misuse injuries and pain are our signals that we’re deviating from the already existing standard of movement. Whether we choose to acknowledge it or not, won’t change this standard. Plain and simple.

 

 

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About the Author

Dr. Nicholas Romanov is the developer of the Pose Method®. A passionate proponent of higher level of education in athletics, Dr. Romanov dedicated his entire career to sports education, scientific research and coaching. An Olympic Coach and a bestselling author, Dr. Romanov has taught on all continents and visited almost every country in the world.
[ Click here to learn more ]

CONTINUING EDUCATION + LIVE SEMINARS + LOCAL CLASSES

Pose Method® 2-Day Educational Seminar is approved for 16 contact hours towards continuing education for Certified CrossFit Trainers and Physical Therapists. Athletes and parents of school age children are encouraged to attend.

The Pose Method® system is a combination of online learning, live seminars and local classes making it the most effective solution available to health and fitness professionals as well as anyone who enjoys an active lifestyle.

Theory & Practice: Gravity + Movement

Gravity is mentioned everywhere – advertising, articles, news, etc. It is talked about in relation to what seems to be a random selection of things like treadmills and some other exercise equipment, shoes, even bras, and a few other curious products. All of that is great yet based on the information mentioned along with the popular word ‘gravity’ shows that gravity is still very much the elephant in the room and it is treated as something that “applies to this but not to that”, “it is here, but not over there”. Fact is – gravity is in the very matrix of our world, gravity is a silent dictator that rules it.

Gravity came before anything else. In order for our solar system to have come into existence, gravity had to have been already present. Here on Earth, gravity is in effect 24 hours a day, 7 days a week, never letting up for even a second. Gravity does vary across the surface of our planet but it is there nonetheless and the differences are not significant enough to affect the way you move. Gravity is everything and it is everywhere. “The most essential characteristics of all biological systems are defined by the Universal Law of Gravity”, wrote a Russian scientist and academic P. Anokhin.

Gravity is the most valuable factor of life on this planet because life as we know it, is impossible without gravity. Without it we couldn’t move the same way, we wouldn’t look the same way, we couldn’t breathe, and we wouldn’t have the air to begin with. The influence of gravity shapes and structures all living creatures including human anatomical and physiological structure, size and weight.

All human movement is gravity-dependent. Whether you’re running, swimming, walking to your car or reaching for milk in your refrigerator – you’re moving under the influence of gravity. Try this, stand straight, relax, feet slightly apart, knees relaxed (not locked, not bent), arms down, upright and relaxed posture. Now shift your body from one foot to another without breaking contact with the ground. Do you feel your bodyweight? That’s how we feel gravity. Wherever we go, whatever we do – it’s always there. But it doesn’t just pull us down like so many would insist. It does so much more.

Leonardo da Vinci was the first to recognize it as a propulsive force, “motion is created by the destruction of balance, that is, of equality of weight for nothing can move by itself which does not leave its state of balance and that thing moves most rapidly which is furthest from its balance”.

Four centuries later, Thomas Graham-Brown expanded on da Vinci’s thoughts, writing, “It seems to me that the act of progression itself – whether it be flight through the air or by such movements as running over the surface of the ground – consists essentially in a movement in which the centre of gravity of the body is allowed to fall forwards and downwards under the action of gravity, and in which the momentum thus gained is used in driving the centre of gravity again upwards and forwards; so that, from one point in the cycle to the corresponding point in the next, no work is done (theoretically), but the mass of the individual is, in effect, moved horizontally through the environment”.

Gravity should be considered as the dominant force on Earth, the strongest mechanical force among all the forces of nature and therefore any movement on Earth is both influenced by, and subordinate to, gravity. Before we can really improve our sports techniques and consequently beat personal bests or world records, we must first acknowledge the effect of gravity on human locomotion and then try to understand it and how it works.

About the Author

Dr. Nicholas Romanov is the developer of the Pose Method®. A passionate proponent of higher level of education in athletics, Dr. Romanov dedicated his entire career to sports education, scientific research and coaching. An Olympic Coach and a bestselling author, Dr. Romanov has taught on all continents and visited almost every country in the world.
[ Click here to learn more ]

CONTINUING EDUCATION + LIVE SEMINARS + LOCAL CLASSES

Pose Method® 2-Day Educational Seminar is approved for 16 contact hours towards continuing education for Certified CrossFit Trainers and Physical Therapists. Athletes and parents of school age children are encouraged to attend.

The Pose Method® system is a combination of online learning, live seminars and local classes making it the most effective solution available to health and fitness professionals as well as anyone who enjoys an active lifestyle.

Theory & Practice: The Pose – How It Works

As mentioned in another article, when moving, our body goes through an infinite number of poses in space and time. Among the multitude of those poses there are those that play an essential role in forming our movement as a whole. Those poses are referred to as ‘key poses’ (or simply poses now), as Dr. Romanov named them, because they are at the center, they connect the preceding pose with the pose that follows, while serving as a conductor of energy and all forces involved, and producing the most efficient movement.

In the Pose Method the understanding of the correct hierarchy of interaction of the forces involved, with gravity in the leading role, allowed to put human movement in a certain perspective where all movement became defined as pose to pose by change of support.

Movement cannot happen without support. If our body does not find support (if the foot doesn’t meet the ground, for example) there will be no movement in any direction. Our body will be in a continuous free fall under the effect of gravity. If there was no gravity or the force was slightly different, than our planet would have a different look to it, we’d have a different appearance and a different way of moving.

Under the dome of the current gravitational field, the most effective single support is the one that’s centered, the one that brings balance yet is ready to destroy that balance in a blink of an eye. Applies to inanimate or living, we are affected by gravity in the same manner. No matter your body type, size, weight or your skill level, it remains true for all. In running, this is what the recommendation “land under your hips, under your GCM (general center of mass), or as close as possible to it” is based on.

When on support a body, any body, can move in any direction. It will move, or it will fall, in whichever direction it is tilted. The quality of movement however will be the outcome of the quality of the body position on support. If you’ve ever slipped on ice you have a pretty good idea of all sorts of random poses that your body goes through when losing support in an unexpected and disorganized manner and trying to find balance while being pull down by gravity. The sequence of events is simple – you fell down not because your body went through random poses, instead you went through those random poses because you slipped, but why did you slip? Because your body pose on support was off and ice leaves tiny room for error in movement.

The Trajectory of Movement

Before attaining support any physical body goes through the motions. If movement happens from support to support, then the path leading to landing on support started at the previous support. And in turn, the current support will determine the quality of the following support.

This is also how the trajectory of your moving parts is determined. No need to copy someone else. Go from pose to pose, change support, and the trajectory of your movement takes care of itself. The better the pose, the quicker the movement from support to support, the better the trajectory…the more efficient you are.

In order for all of this to work properly, the pose assumed by your body on support must have certain characteristics. It must be a pose of balance that offers stability yet does not affect the momentum of movement. It has to be compact and focused.

Mechanically the pose and change of support are identical for everyone. Though we are all unique, gravity affects us all in the same manner and the effective way to deal with it applies to all. While Ferris wheels in different locations are painted in different colors and have different design of passenger cars, the mechanical work of the main unit remains the same.

So the pose of the body while on support is everything. If yours resembles a starfish, while very stable, you most likely won’t move too fast. But if you’re correctly posed and change support quickly you will be fast, efficient and injury free.

The Pose

  • harnesses the power of elements of previous movement, and defines the consequent movements
  • defines optimized interaction of all forces involved
  • helps integrate all forces during the support phase
  • provides for the best interaction with support, and support is an essential part of any movement
  • significantly optimizes muscular efforts
  • utilizes natural properties of the entire muscular skeletal system like muscles’ ability to contract and relax, and their elasticity, etc.
  • eliminates extra unnecessary movement so less energy is spent
  • allows to move with sharp precision
  • simplifies teaching and learning of any technique

In running, or any other athletic activity, using pose allows us to tap into the natural forces at play. Physics and biomechanics performing in harmony. Key position allows us to flow within the natural forces and use their power, instead of clashing with them and suffering the consequences.

You get better results with less effort and don’t traumatize your body in the process.

About the Author

Dr. Nicholas Romanov is the developer of the Pose Method®. A passionate proponent of higher level of education in athletics, Dr. Romanov dedicated his entire career to sports education, scientific research and coaching. An Olympic Coach and a bestselling author, Dr. Romanov has taught on all continents and visited almost every country in the world.
[ Click here to learn more ]

CONTINUING EDUCATION + LIVE SEMINARS + LOCAL CLASSES

Pose Method® 2-Day Educational Seminar is approved for 16 contact hours towards continuing education for Certified CrossFit Trainers and Physical Therapists. Athletes and parents of school age children are encouraged to attend.

The Pose Method® system is a combination of online learning, live seminars and local classes making it the most effective solution available to health and fitness professionals as well as anyone who enjoys an active lifestyle.

Theory & Practice: The Extensor Paradox in Running

The original article (below) on the topic at hand, was published in Biomechanics of Distance Running in 1990. As you read the data and conclusions from this research you’ll see that the scientific community was not ready to accept the idea of the role of gravity as a leading force in running. A classical vision of gravity strictly as a vertical force was predominant in the scientists’ minds and didn’t allow them to look at the facts from a different perspective. The most important thing there, a relationship between extensor muscles and gravity as one non-conflicting system with reciprocal coordination between them, was overlooked.

The Data

The data in this article clearly demonstrates Nature’s wisdom of coexistence, when one force yields to the other to allow them both be used to their fullest. In the Pose Method the concept of gravity as a leading force in forward movement is the most fundamental one, and the data from the extensor’s paradox article below confirm this.

I would like to specifically point out for you the data showing when the quad muscles cease any electrical activity. According to the research data, it happens immediately after the mid-stance, when according to the traditional point of view the so-called “push off” efforts are supposed to be exerted.

This conflicting information brought the authors to this particular name of the article. The commonly accepted understanding of the leg extension as a forward propulsive force in running did not get any support by the data provided by this research. But, at the same time, with this data available, the researchers did not come to any conclusions that should have pointed out the role of gravity in running.

 

The most important thing there, a relationship between extensor muscles and gravity as one non-conflicting system with reciprocal coordination between them, was overlooked.

The Logic

In the absence of pre-existing standards and guidelines, we must step away from the microscope and look at the bigger picture. Figuring out the hierarchy of the existing forces and how they work/interact elsewhere and everywhere allows us to lay down the ground rules. This initial sorting of already known facts is essential in formulating a concept.

Currently our understanding of the force of gravity is limited and yet we know just enough to understand that it is the glue that holds everything together. Thus it is considered the leading force. If we accept it as such in relation to our entire planet, then we must accept gravity as the leading force in horizontal movement in running as well, all other forces are subordinate.

Jumping ahead to the work of muscles and our entire body framework of bones, connective tissues, etc it is logical to suggest that when we see a muscle group cease activity that it happens so specific muscle behavior does not interfere with the work of gravity but falls in line with it. It is easy to say that this logic has been established from the beginning of biological life on Earth. From this point of view, our conscious efforts to produce the forward propulsion were “ignored” by Nature.

The Practice

Some perception of muscle efforts on support, which we have during the support time right before and during mid-stance, gives an illusion of this “push off” happening. Most runners sincerely believe in ‘push off efficiency’ and its necessity in order to run, because of their perception and deceptive visual appearance. The fact is that we feel tension interpreted as a push simply because we arrive to the single point of support with our entire body weight on it for a fleeting moment in time.

Try this. Stand in the running pose and start falling forward. Now push off. Be honest with yourself instead of just trying to prove me wrong. Could you push off? No.

Our common sense is based on and is limited by our understanding of the subject, and hence is a very deceptive thing that often doesn’t coincide with abstract logic, which we have to use in order to see the hidden reality of functioning of systems. For this matter we have to use the system of reference of Nature, applying scientific terminology, according to which Gravity is a predominant force by all accounts. Then and only then we’ll be able to see how the forces interact within the hierarchically structured system, each with its own space and time of involvement in the action of running.

 

BIOMECHANICS OF DISTANCE RUNNING

Human Kinetics Books, 1990


Chapter 6. Muscle Activity in Running. The Extensor Paradox Experiment
by Irene S. McClay, Mark J. Lake, Peter R. Cavanagh

It is well known that knee flexion occurs just before and immediately after footstrike during running to cushion the impact of landing (Milliron & Cavanagh, this volume). Once the downward movement of the center of gravity associated with this cushioning phase has finished, knee extension begins and the propulsive phase of the cycle continues.

There is evidence from Brandell (1973) and Mann and Hagy (1980b) that the quadriceps are generally silent during the phase of knee extension following the cushioning. Few experiments have focused on this puzzling aspect of knee joint action during running. The purpose of the experiment described in this section was to examine the activity of the three heads of the quadriceps that are amenable to surface recording during distance running and to simultaneously measure the angle of the knee joint.

Subjects and Speed

Six male recreational runners, ages 19 to 26, experienced in treadmill running with no history of recent injury, volunteered for the study. Each subject ran at a constant speed of 4.0 m · S-¹ on a motorized treadmill. This speed was chosen as it was in the middle of the range used by previous workers.

Equipment and Method of Analysis

To investigate knee extensor muscle activity during the stance phase of running, EMG of the vastus medialis, vastus lateralis, and rectus femoris muscles of one leg were recorded using a battery-powered GCS 67 Electromyographic Processor. Silver-silver chloride electrodes with on-site preamplifiers were placed in the middle of the muscle belly after thorough preparation of the skin. An inertia switch attached to the heel was used to define the cycle endpoints and knee angle was recorded simultaneously with a self-aligning ULGN-67 Electrogoniometer. This design compensates for errors in placement and does not assume a fixed center of rotation for the joint. The electrogoniometer was calibrated for knee angle by comparing voltage output against knee angle measured by a protractor.

The EMG processor, together with the goniometer and footswitch signals, were interfaced with an SMS 1000 computer, which sampled at a rate of 500 Hz per channel. The raw EMG signal was prefiltered using a high pass filter of 75 Hz cut-off frequency. Custom software allowed for storage, processing, and display of the data. An example of the raw data for the complete 5-second sampling period is shown in Figure 6.6a, and the region surrounding footstrike is shown with greater resolution in Figure 6.6b.

Figure 6.6a. A 5-s raw experimental record.

Figure 6.6b. A portion of the same experimental record surrounding footstrike shown with greater time resolution.

Five-second samples were collected after each subject had undergone a warm-up period at the test speed. This allowed at least six full cycles of running to be recorded for each individual. For each period of stance, the phasic activity of all three muscles was subjectively determined by comparison with a noise-free baseline. Data from six footstrikes were examined, and mean values were obtained for the time at which rectus femoris, vastus lateralis, and vastus medialis muscle activity ceased. The beginning and end times of the knee extension phase following initial flexion were also determined.

Results

Figure 6.7a illustrates the mean results of six footstrikes for a typical subject. It can be seen that approximately 85 milliseconds before footstrike, muscle activity begins while knee extension is under way. Vastus lateralis is the first to show activity, some 25 milliseconds before vastus medialis and 60 milliseconds before rectus femoris. This period of muscle activity appears to help in stabilizing the leg in preparation for footstrike. All three muscles are active through footstrike while knee flexion occurs, but they cease activity simultaneously approximately 20 milliseconds after peak knee flexion has been achieved. In this subject knee extension continues for a further 150 milliseconds.

Figure 6.7a. Results of phasic quadriceps EMG and knee angle for a typical subject averaged over six footstrikes.

Figure 6.7b Ensemble average results of six subjects of the relationship between phasic quadriceps EMG and knee angle. The values of peak knee extension prior to footstrike, peak knee flexion during stance, and peak knee extension after stance have been joined by straight lines as the mean curve was not determined.

The mean results for the group as a whole are presented in Table 6.1 and shown schematically in Figure 6.7b. The mean time of knee extension that was not accompanied by quadriceps EMG was 133.7 milliseconds (SD = 16.5).

Flexion extension durationMean all muscle off after peak flexionMean duration of silence during extension
Mean for group ±SD162.8

19.5

29.2

10.4

133.7

16.5

These results are further illustrated in Figure 6.8, where electrical activity is indicated by the presence of shading over the muscle. The amplitude of the activity is also schematically indicated by the intensity of the shading. The large amount of knee extension that occurs in the absence of muscle activity is readily apparent from this figure.

Figure 6.8. The amplitude of EMG activity throughout the stance phase of running. (The intensity of shading indicates relative amount of activity.)

Discussion

For the group of runners examined in this study, it is clear that the quadriceps cease their activity shortly after peak stance phase knee flexion has occurred. A phase of knee extension of approximately 130 milliseconds continues without the assistance of the quadriceps. The function of the quadriceps must therefore be described as principally controlling the descent of the body center of gravity after landing. Certainly they help to initiate knee extension, but they rapidly become quiescent when knee extension has been under way for only about 30 milliseconds, a time during which less than 5 degrees of extension has been achieved. The duration of electrical silence in extension is large enough to exclude the possibility that electromechanical delay (EMD) between EMG activity and force production may explain the paradox. EMD time in concentric muscle action has been determined to be 40 to 55 milliseconds (Cavanagh & Komi, 1979; Norman & Komi, 1979), and in rapid movements it may be possible for EMG activity to have terminated before force can be detected.

A reasonable hypothesis may be that hip extensor action during the second half of the stance phase is causing the knee joint to extend. However, if one examines the co-activation of the quadriceps and hamstrings in Figure 6.3, it is apparent that many investigators have found these muscle groups to cease activity at about the same time in the cycle. Neither does there appear to be a prolonged period of gluteus maximus activity that would provide an explanation. Figure 6.4 indicates that the last extensor muscle to cease activity during stance appears to be the gastrocnemius, which is of course also a knee flexor. Because only the quadriceps were measured in the present study, it is not possible to say with certainty what patterns of activity were exhibited in other muscles in these particular subjects. These experiments have, however, shown that the notion of an extensor thrust-with plantar flexors, knee extensors, and hip extensors all being active in late support to generate forward and upward thrust – is in need of modification. They also indicate that the problem is worthy of further investigation using a kinetic approach in addition to multi-channel EMG so that the joint moments can be determined.

 

 

Recommended:

 

 

References

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  • Brandell, B.R. (1973). An analysis of muscle coordination in walking and running gaits. In S. Cerquiglini, A. Venerando, & J. Wartenweiler (Eds.), Medicine and Sport: Biomechanics III (pp. 278-287). Basel, Switzerland: Karger.
  • Carlet, M. (1872). Essai experimental sur la locomotion humaine: Etude de la marche [Experimental test on human locomotion: Study of walking]. Annales des Sciences Naturelles, Sect. Zool., XV.
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  • Grieve, D.W., Pheasant, S., & Cavanagh, P.R. (1978). Prediction of gastrocnemius length from knee and ankle joint posture. In E. Asmussen & K. Jorgensen (Eds.), Biomechanics VI-A (pp.405-412). Baltimore: University Park.
  • Hubbard, A.W. (1939). An experimental analysis of running and of certain differences between trained and untrained runners. Research Quarterly of the American Association of Health and Physical Education, 10(3), 28-38.
  • Hudgkins, C.V., & Stetson, R.H. (1932, July 15). A unit for kymographic recording. Science, p. 60.
  • Kramer, H., Kuchler, G., & Brauer, D. (1972). Investigations of the potential distribution of activated skeletal muscles in man by means of surface electrodes. Electromyography and Clinical Neurophysiology, 12, 19-26.
  • MacIntyre, D.L., & Robertson, D.G.E. (1987). EMG profiles of the knee muscles during treadmill running. In Bengt Jonsson (Ed.), Biomechanics X-A (pp.289-294). Champaign, IL: Human Kinetics.
  • Mann, R.A., & Hagy, J.L. (1980a). Biomechanics of walking, running, and sprinting. American Journal of Sports Medicine, 8(5), 345-350.
  • Mann, R.A., & Hagy, J.L. (1980b). Running, jogging and walking: A comparative electromyographic and biomechanical study. In J.E. Bateman & A. Trott (Eds.), The foot and ankle (pp.167-175). New York: Thieme-Stratton.
  • Marey, E.J. (1972). Movement. New York: Arno. (Original work published 1895)
  • Nilsson, J., Thorstensson, A., & Halbertsma, J. (1985). Changes in leg movements and muscle activity with speed of locomotion and mode of progression in humans. Acta Physiologica Scandinavica123, 457-475.
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  • Norman, R.W., Nelson, R.C., & Cavanagh, P.R (1978). Minimum sampling time required to extract stable information from digitized EMGs. In E. Asmussen & K. Jorgensen (Eds.), Biomechanics VI-A (pp.237-243). Baltimore: University Park.
  • Pare, E.B., Stern, J.T., & Schwartz, J.M. (1981). Functional differentiation within the tensor fasciae latae. Journal of Bone and Joint Surgery, 63-A(9), 1457-1471.
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  • Warfel, J.H. (1974). The extremities (4th ed.). Philadelphia: Lea & Febiger.
  • Winter, D.A. (1979). Biomechanics of human movement. New York: John Wiley & Sons.
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About the Author

Dr. Nicholas Romanov is the developer of the Pose Method®. A passionate proponent of higher level of education in athletics, Dr. Romanov dedicated his entire career to sports education, scientific research and coaching. An Olympic Coach and a bestselling author, Dr. Romanov has taught on all continents and visited almost every country in the world.
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