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All posts for the month January, 2013

Even A Caveman Could Do It

What if, along the lines of the Geico commercial, running could be so simple that even “a caveman could do it?” Of course, cavemen ran– they had to. Yet, today, probably because running has devolved from efficient survival-oriented locomotion into recreation and sport, it has become laden with excess. It’s no longer simple, and the forest is lost for the trees.

It doesn’t help that all the wild and wooly dogma of natural running gurus, and coaches, sports scientists, biomechanists, and physical therapists regarding running form echo those proverbial blind men describing the whole of an elephant from each of its disparate ends. They’re all as wrong as they are right. Yes, elephants have trunks, and ears, legs, bellies, and tails, but we know it’s only by stepping beyond a limited reference point that lets us appreciate the whole beast. So, it’s only by gaining perspective that we can understand how, regardless of their methods, runners all run the same way– by harnessing gravity. This is the elephant in the room that until now has been roundly ignored.

Our modern sophistication blinds us to the fact that humans developed within Earth’s gravitational field, and therefore we are ideally suited to redirect this universal force as well as any other animal. And, we’ve been doing it successfully without outside support for millions of years. While the underpinnings are pretty complicated, Nature’s already done the math. All we’ve got to do is get out of our own way…and run.

Consider This

In running there are variables and invariables. An invariable is common to all runners. A variable is something that could be added, but doesn’t have to be. For instance, shoes are variables. Even feet are variables. Legs, however, are invariables. You must have them to run. Of course, you can keep your feet, and your shoes, and as you step through this sample running stride with me you’ll learn to recognize the parts of your own running form you will want to keep, or release.

But, why would changing or refining running technique be important at all? Can’t we just run? Well, if there could be such a thing as correct running form wouldn’t it just make good sense that by using it we may be able to run farther, run faster, and run with less chance of injury?

So, consider that correct running form asks only that runners eliminate the variables, and reinforce the invariables. We’ll start with landing, and conclude with leaving the ground.

Heel Strike

Common to about 75% of runners, the heel strike has been routinely maligned and celebrated. What’s it all about?

Initial Ground Contact: Heel Strike Landing— well ahead of the GCM

A heel strike landing actively swings the foot well out in front of the runner’s general center of mass (GCM), into a braking position. Imagine repeatedly reaching out with a straight leg and a heel edge that collides with the ground to hold off the body weight on… BAM… every… BAM… single… BAM… running… BAM… stride… BAM… BAM… BAM… BAM. Ouch! Right?

Can you say,

  • Knee pain?
  • Hip pain?
  • Back pain?

Yeah, I thought you could.

Yes, the body makes some concessions for heel first landings by rolling at the ankle and rotating at the hip, but, in spite of Olympian Jeff Galloway’s description of its being “cushioning,” a heel strike adds a lot of noise to an otherwise elegantly quiet system of support.

You see, a heel strike adds what’s seen on a graph as a force spike well ahead of our natural supportive loading. This impact at touchdown sends a tremor of about two times body weight straight into the foot, through the leg, and into the hip and back. You can even hear what Hunter S. Thompson called “a hell broth of slapping and pounding feet” as any group of actively landing runners passes. Check out Dan Leiberman’s Barefoot Running: The Biomechanics of Foot Strike video clips and realtime force plate graphs and you’ll immediately see how this undue loading of the runner’s body occurs through the severely active landing of a heel strike.

But, because most runners today are wearing big, bulky shoes they’re not going to feel very much regardless of how they interact with the ground. In fact, many runners don’t really know whether or not they heel strike. They’ve probably never thought about it because they never felt the need. Take off those clunky shoes, though, and run barefooted over a paved surface and any heel strike becomes a concern right away. That’s because instead of a thick, wide, and heavily padded shoe bottom they are now subjecting their small, hard, naked heel bone– hardly the body’s favored touchdown point– to an unforgiving ground. They’ll quickly put their shoes back on or run start running differently.

Now, since there are some 25% of runners who do not “naturally” heel strike (and without shoes there would surely be a whole lot more) it’s clear that heel striking is a variable part of a running stride.

Mid Foot Landing

Since the actual “mid foot” is a series of bones at the apex of the arch it cannot actually function as a landing pad, right?

Skeletal Diagram of Foot— note “Midfoot”

So, what’s really meant by “mid foot” is a flat-footed landing where both heel and ball of foot touch the ground simultaneously. This is mostly a visual illusion. Shoes tend to have elevated heels which would favor a forefoot landing…er, a heel strike… er, a flat-footed landing, but it’s hard to tell because it can’t really be felt, anyway. It can be measured by pressure sensitive devices, but typically contact occurs at either the forefoot or the heel.

One characteristic of this active “mid foot” landing is that it occurs, like the heel strike, well in front of the body’s general center of mass (GCM), so again, it’s a braking force. While it usually doesn’t produce an impact transient that’s as abrupt as the heel strike, an unnecessary force is still present.

Initial Ground Contact: Midfoot Landing— well ahead of GCM

For such an active landing the penalties may include:

  • Sliding inside the shoe– friction equals blisters and toes being jammed into the toe-box can result in black toenails;
  • Muscles absorbing greater loads, for longer periods, increases fatigue;
  • And, the delay of falling into the new stride just perpetuates this cycle.

Another negative with a flat-footed landing is that it bypasses, and thus wastes, the metabolically free elastic rebound inherent within the foot, and the coordinated mechanisms of the ball of the foot and the ankle joints. Worse, plenty of people when learning to run barefooted, or with minimal footwear, or even when trying out a forefoot landing in any other shoes tend to add unnecessary effort. They errantly reach out toward the ground to find their next support. This active landing pits firing muscles– calves and quadriceps– and a misaligned skeletal structure against gravity during landing. Injury often follows. Sadly, blame is normally directed at the (lack of) footwear rather than at runners’ faulty form.

Again, since some runners do not land on their so-called mid foot, it too is a variable component of running.

Paw Back

The idea that a runner can slam their foot into the ground to catapult themselves over that point of contact, and into the next stride is again a visual illusion, a mistaken interpretation of hamstring muscles activity prior to ground contact, and a gross misunderstanding of biomechanical function. For now, because paw back so convolutes any reasonable concept of a natural landing in running we’ll leave it as just another affectation that adds damaging impact– a variable.

The Running Pose

Every runner, no matter how they get into it, reaches the running Pose. Some land in it as they are touching down. The rest progress into it following the aforementioned variables above.

Initial Ground Contact: Landing Close to Pose Position

And, into the Pose Position…

Pose Position

The running Pose is seen as one singular point in space and time that separates the previous stride from the next. Its key visual characteristics are that bodyweight is on the ball of the foot, the ankle and knee joints are bent, and the swing foot is tucked up beneath the hip. The less obvious indicators of the running Pose occur when the runner’s general center of mass (GCM), the swing leg’s center of mass, and the ball of the foot (BOF) are all aligned. Ideally, this happens right at the “vertical moment” but it’s often realized just slightly beyond (as above, and as detailed below). Until you reach this position you’re still in the previous stride.

The Vertical Moment

What’s important to note is that by landing in the running Pose the loading curve of ground reaction is smooth and gradual as the lower limb is allowed to exercise its natural biomechanical springiness. The two to three times bodyweight load of ground reaction applied here is exactly the force that modeled our running bodies, and is distinct from impact, the undue shock created by those active landings above. I might point out that the vast majority of running injury stems from landing. Landing in the running Pose eliminates one of the prime causes of injury.

From the running Pose– the first invariable— emerges a standard from which to distinguish incorrect and correct running form.

So it’s here, from this Pose position, the runner stands on the precipice, ready to give himself to gravity, and begin falling forward at 9.8m/sec./sec. into the next stride. The goal then, and what defines correct running form, is to get into and out of the Pose position– onto and off of support– “on time.” We’ll get to that in a bit.

The Fall

Opinions abound with regard to the propulsive phase in running. Where and how it happens continues to fuel heated exchange between authorities, with perhaps their sole agreement being that it occurs during ground contact.

From the Pose Method perspective the drive in running comes from gravitational torque, rather than by muscular efforts. In short, muscle elasticity (quads / calves) lifts the body in a fraction of the second following mid stance, and muscle activity (glutes and hamstrings) stabilizes the body through the duration of the Fall. This just happens for every runner. Small children do it naturally, and the most highly coached runners do it often in spite of their training. The Fall is how we redirect the downward pull of gravity, and translate rotational motion into horizontal movement.

Once the runner reaches the Pose position he immediately begins falling forward like a felled tree. This occurs in an instant, and within a narrow range. Imagine a pie slice between 12:00 and 12:04 on an analog clock face. That’s our usable range of Fall– 0° to 22.5°. Identify this visually: the runner holds the Pose position, and tilts forward on the ball of the foot. Note that the heel comes off the ground as the runner pivots on his support (BOF) through his speed appropriate range of Fall. This Fall continues until the Pose position is dissolved. That happens when support ends, meaning when ground reaction drops below “one bodyweight.” This is seen when the swing foot is untucked and begins reaching for the ground.

From here…

Beginning Angle of Fall

To here…

Ending Angle of Fall

Ultimately, no one runs until they Fall. The Fall, then, is the second invariable component of running.

Active Knee Drive

Even within the inertia of the conventional wisdom, that is, that running is a result of muscles’ efforts, disagreement with regard to knee drive stirs up further confusion. Some describe the swing leg recovery phase as reflexive, which it is. The thigh, when left to its own function, simply rotates around the hip in synch within the runner’s stride. Others advocate strong volitional hip flexion, but still argue over whether it’s an upward or a forward drive, and what final purpose it’s serving. Does it add to stride length, increase horizontal speed, or just result in greater vertical oscillation?

To be sure, some runners flex at the hip quite a bit, some don’t. In fact, the previous “World’s Fastest Man,” Michael Johnson was known for, among other stride anomalies, low knees— anathema to sprint culture. Go figure.

So, “active” knee drive is a variable. What’s more, because the knee can only trace the arc of a circle, since it hinges at the hip joint, any notion of forward or upward knee drive is imagined.

Paw Back, Foot Drag

Common descriptions of the propulsive phase of running include explanations like…

The extension of the hip is where the power comes from, not from pushing with your toes or other mechanisms which are commonly cited. The hip should be thought to work in a crank like or piston like fashion. This speed and degree of hip extension is what will partially control the speed. A stronger hip extension results in more force application and greater speed, thus how powerfully and rapidly the hip is extended helps control the running speed. — Steve Magness

…and…

[With paw back you] help propel your body forward so that your center of gravity is as far forward as possible prior to the push-off. — Michael Yessis, Ph.D.

…and…

[As per Sir Isaac Newton] in order to create horizontal propulsion, we must pull straight back against the ground instead of pushing down into the ground… [which] involves pivoting the leg backward from the hip with the entire leg as a fixed unit… — Ken Mierke

So, as far as I can tell, the gist here is that the runner should try to pull himself across the ground with great muscular contractions. Problem is, the posterior horizontal ground force always remains below bodyweight meaning, as per Newton’s Third Law– equal and opposite– that that sort of horizontal acceleration just doesn’t add up. What’s more, the proponents of foot drag or paw back seem to turn a blind eye to the reality of the runner’s GCM actually bouncing from stride to stride, and swinging around its support on the ground (as described in Pose/Fall). Actions such as paw back and foot drag can certainly be introduced into a running stride, but, in general, runners– including Usain Bolt, and you, too– can be seen running perfectly well without such variable affectations.

Push Off

Though it’s an illusion, typical pictures of runners sure appear to be powerfully launching themselves forward stride by stride.

Push Off

Here’s one explanation…

The key action that occurs in the push-off is ankle joint extension. Push-off is not, as commonly believed, caused by the glutes and hamstrings being involved in hip joint extension or the quadriceps driving knee joint extension. Observe the ankle joint… and you can see it goes through a substantial range of motion. — Michael Yessis, Ph.D

.

Now, here’s another.

Recall the pie slice range of Fall from 12:00 to 12:04– any push can only be upward. Further, at the point of greatest apparent push, vertical ground forces have dropped below body weight, and the “pushing” foot is, right then, being pulled from the ground. The biceps femoris is starting to bend the knee, and Achilles tendon activity reflects an elastic component rather than muscle action.

In any event, while some runners do try to push into the ground, and others just leave their foot there for too long, the support leg may indeed straighten at the end of ground contact. This certainly looks powerful and Puritanically significant, effort-wise. But, a push only hinders the runner by preventing him from changing support in a timely manner, and burdening his mind and body with misdirected attentions. Since many elite and recreational athletes– and skilled Pose runners– release the ground with a bent knee and a neutral ankle joint, the so-called push off is yet another variable.

Pull

To run we must change support. It’s self evident– the foot has to let go of the ground. So, the Pull is the third invariable.

Pull— release the ground to change support

But, there’s a variable within this invariable: “when?” On time! That means once the Fall is complete, which for most is around 5° to 20°. But I’m not taking a protractor out with me to run, and I’ll wager neither are you. Ultimately, we need to know by feel when it’s time to pull the foot off the ground.

In a perfect world the Pull is handled reflexively. In our world shoes blunt our natural feedback mechanisms, the sensory acuity that provides for precise timing. As well, any willful intent of trying to do more– paw, push, what-have-you– as the foot is being drawn away from the ground only muddles this timing.

Plus, and perhaps a surprising piece in this puzzle, is that we’re also subject to our natural fear of falling (one of two innate fears, the other being of loud noise). Fear of falling can have us reaching out with the swing foot to find terraferma as we continue clinging to the ground behind us. Running, then, looks a lot like walking.

But what if we reframe this fear as a cue? That is, simply, that our support or the security of one body weight is coming to an end. Then, things can change. When you get comfortable giving yourself freely to gravity and feeling the Fall, you’ll begin reacquainting yourself with the primal grace that our earliest forebears enjoyed. Your senses will awaken and will tell you exactly “when.” The Pose Method gives you renewed access to these perceptual fluencies, and it gives them a voice– Pull!

An Aside

While this isn’t an exercise article, per se, it is worth pointing out here that using specific drills are more valuable than, for instance, just mindlessly increasing training mileage. We, as runners, want to reinforce these invariable elements of running which refine the specific skills set that ensures our most precise movements, and ultimately leads us to heightened perception. As well, training without shoes and on bare feet helps to revive our natural physical and mental awareness, too. Less is more!

Insofar as performance, endurance and speed rely on consistent execution– high quality technique. Technique depends on precise neural conditioning, which stems from increasing our awareness of incorrect and correct…timing. Drills are the direct route to becoming a safe and efficient runner, and training volume is valuable only insofar as your good technique can be maintained.

Conclusion

Again, I look back to our prehistory where once down from the trees and exploring our new world with the great strength and dexterity of our hands and arms, the task of bipedal ambulation was relegated to lower nerve function. Over time, as our intent carried us farther from our arboreal habitat and demanded greater levels of mobility our bodies morphed into their present iteration. All this was occurring because we were unconsciously working with the dominating force of gravity to effect such physical changes. Cavemen probably didn’t think much about running form, but you can be certain that because for survival they had to run, and run barefooted at that, they ran right– like any other wild beast.

You can witness this primal awareness in children as they routinely test the boundaries of balance and motion while learning to stand, to walk, and then to run. They use just the invariable elements– Pose, Fall, Pull. It’s only later, after their senses and freedom of movement have been blunted by footwear, and their inherent understanding of movement have been skewed by the prejudices of others that they must be taught, or more accurately reminded, of correct running form.

So, yes, running is so simple that even a caveman could do it. The question is, now that it’s been distilled for you, down to its simplest form– Pose, Fall, Pull– can you do it, too?

Notes:

  • Vertical Moment, Beginning Angle of Fall, and Ending Angle of Fall stride analyses are from a running stride presentation by Nicholas Romanov, PhD. at the American Pose Coaches Conference, 2012. Photos of presentation by Charles Blake, DPT.
  • This post was inspired by the collaboration between Severin Romanov and Charles Blake, DPT, and the “Anatomy of a Stride” presentation by Severin Romanov, at the American Pose Coaches Conference, 2012.