Run for Your Life

by Mark Cucuzzella

  Now picture the legs of a walking human as, quite simply, two pendulums. The kinetic energy of one leg is highest as the foot swings forward, at the bottom of the swing, and its potential (stored) energy is at its high point—fully loaded—when the foot is momentarily stopped and planted on the ground.

  The efficiency of our dual leg pendulums, in freely carrying our movement forward, is only about 65 percent. This means that the additional 35 percent of the energy needed to complete each step (and keep moving) must come from the muscles. But there’s room for improvement in walking efficiency. One study looked at Kenyan women who carry loads on their heads, and found that they shorten the midstance pause in their stride in order to minimize the energy dissipated into the ground. By converting more of their potential and kinetic energy into forward motion, they need less of a boost from their muscles (and expend fewer total calories of energy) than most of us would need to execute the same task. When carrying loads, energy conservation is at a premium, and the Kenyan women’s efficiency of movement rises from 65 percent to as much as 80 percent.

  HOW DOES THIS LOOK IN STOP-ACTION?

  When we examine the mechanics of walking, how do the parts come together into this ordinary yet remarkable task?

  Our joints and muscles don’t work in isolation. We should think of the body as a complex array of parts linked tightly (and sometimes loosely) in a dynamic, interdependent, spring-loaded chain of movements. Let’s dissect a normal walking stride.

  The fleshy pad of the heel is the first part of the foot to strike the ground. Some of the ground impact energy is dissipated by this cushioning. The ankle joint absorbs impact next, followed by the knee, the hip, and finally the spine. The myofascial system, which provides balance and makes small corrections, also absorbs and dissipates much of the impact load, and stores some of that energy, too.

  As the stride progresses, the landing leg becomes the trailing, toe-off leg, and the toes flex upward (dorsiflex), which resets and stabilizes the arch of the foot. At toe-off, the toes extend (causing plantar flexion of the ankle), the knee extends, the hip extends, the spine sways (or arches) slightly, and the soles point rearward and up.

  WHERE DOES THE POWER AND SPRING COME FROM?

  The supporting hip muscles (adductors, abductors, and glutes) must be strong, at the same time that the hip flexors (the group of muscles that includes the iliacus, psoas, and rectus femoris) must be long and mobile, for maximum backward leg extension from the hip joint. Tight hip flexors, and toes that don’t readily dorsiflex (bend up), lead to a shortened stride.

  Good locomotion depends on the strength and elasticity of our fascia and muscles during the push-off phase of the stride (when the foot is on the ground). Once the foot is airborne, it can’t offer propulsion.

  Tight hip flexors + stiff ball of foot + stiff shoes = short stride Good mobility at hip and forefoot + flexible shoes = long stride

  A short stride + minimal counter-rotation of the shoulders and pelvis + little hip extension = weak spring

  A long stride + good counter-rotation of the shoulders and pelvis + good hip extension = powerful spring

  There’s another dynamic motion that occurs in walking: the shoulders counter-rotate (in the transverse plane) relative to the pelvis. This creates diagonal, springlike tension in an “X” across the front of the chest. With good hip extension, the tension and energy in this counter-rotation spring-loads the trailing leg for a rapid and efficient return to the front.

  Now that we’re up and walking, let’s go through some simple adaptations we can make to improve the ease and efficiency of movement.

  Posture, as we discussed in the previous chapter, is the best place to start in developing solid, efficient walking form. When your posture is good, your body’s mass is supported by its structure, not by its muscles. If you suffer pain and fatigue from walking, or even from standing, this is the first clue that you have been using your muscles for balance, and that your posture is out of alignment. (A “museum stroll” is generally more tiring and less efficient, you might have noticed, than a power walk at higher speeds. This is because when you stroll, you are using the power of your muscles instead of the dynamic, load-and-spring feature of muscles and tendons, and are disrupting the rhythmic pendulum swing of the legs that occurs at a normal walking pace.)

  Envision holding a garden rake with one hand from the end of its handle, the rake straight up in the air. When the rake is well balanced, it takes little effort to keep it in that position. But holding it even slightly out of alignment requires significant strength. It’s the same with your spinal column. Shoes with elevated heels only exacerbate this postural misalignment.

  DON’T BE UP THE STREET WITHOUT A PADDLE

  The next time you walk, think of it as a new, mindful adventure.

  Begin by straightening your frame so that it is tall, yet relaxed, and breathe from the diaphragm (as learned in the previous chapter). Gently lean forward from the ankles, and propel yourself into a walk. Think of your leg as a paddle that you place on the ground (the water), and by stroking it back it moves you (the canoe) forward.

  Lead from the torso, not from the head. Maintain your gaze directly forward, not downward. As you walk, try this: place your hands on the front of your hips, and with each step make a conscious effort to leave each big toe on the ground for a split second longer than you usually would, and roll off of it as you push behind you. At the end of the stride, let the bottom of your foot turn up slightly—releasing the sole of your foot to be “tanned by the sun.”

  Your knee remains slightly bent on landing, but it fully extends on toe-off. Forward locomotion is all about the leg behind you, not the one in front. Pay attention to your powerful posterior muscles as they press downward and behind you. The trailing leg will naturally lift and bring itself forward. (The more extension you have behind you, the more readily your leg springs to the front.) As your hips open and your glutes activate, your stride will lengthen.

  Let yours arms swing gently to and fro from the shoulders, like pendulums, with hands relaxed. Notice your feet. Your rounded heel works like a ball: it is designed to roll forward. As your weight shifts from heel to big toe, picture the mechanics of a wheel—one that smoothly rolls through the heel—rather than a jolting, sequential heel strike. Basic physics affirms that it is inefficient (and fatiguing) to walk by overextending your leg forward, locking your knee, and hitting the ground with a thud. Each step may not seem to land with much impact, but multiply that by two thousand per mile.

  To follow all this and engage these subtle changes may feel strange at first, but your technique will become more fluid and natural as you progress. Walking will become gliding.

  THESE SHOES ARE MADE FOR WALKING…

  The principles that apply to running shoes (see the chapter on feet) apply to walking footwear as well. Your health care provider or shoe store may have told you to get a cushioned shoe with good arch support. But these narrow, soft, arch-supporting shoes only interfere with the function of your feet, disrupt your posture, and inhibit forward propulsion. In particular, elevated heels allow (and even encourage) a hard heel strike, triggering compensations in every joint from your ankle to the knee and hip, and up through the back. And arch supports block the natural, leaf-spring-like flattening of the foot. Some people complain of “fallen arches,” but these are usually cases of failing arches—from years of disuse.

  Remember these footwear bricks from a generation ago?

  It’s best to avoid hiking boots like these that don’t allow a natural, foot-to-ground connection.

  With practice and patience, the afflictions arising from modern shoes can almost always be reversed. Ernest Wood’s Zen Dictionary states, “The foot feels the foot when it feels the ground.” You will rediscover this connection, and the miraculous function of your feet, as you transition into thinner, flat, and more f
lexible shoes with a wide toe box and no arch support. Such minimalist shoes allow your toes to spread apart and provide balance, and let your foot pronate and your arch flatten, then release locomotive power when they spring back.

  Shoes with wide toe boxes, and with no arch support or heel lift, are ideal for walking. Elevated heels, common in modern “cushy” running shoes, compromise foot balance and posture, and encourage a hard heel strike.

  I’m confident that once you progress (gradually) to wider- and thinner-soled shoes, you will never go back. But do talk to a knowledgeable health care provider if you have a structural or congenital condition that necessitates a supportive shoe.

  Shoes with stiff, rocker-shaped soles—there are many of them—dampen natural energy return and generate instability as your foot rolls forward. The very front part of these (and most other) modern shoes curves slightly upward in what’s called “toe spring,” an intentional design feature that presumes that the foot needs help in “rolling” into the next step. But our toes were made to bend and flex and grip the surface of the earth. When shoes aim our toes toward the sky, our toes can’t help us balance or propel. Ironically, the rocker shape also doesn’t allow the toes to bend completely upward (dorsiflex) on toe-off—yet this is needed to create the stable platform that provides optimal propulsion.

  It’s fairly simple: we don’t need shoes to try to do the foot’s work for it. After all, the trial-and-error design features of our feet have evolved for a very long time. (The Laetoli footprints date to about 3.7 million years ago.)

  My father had a hip replaced, and then a knee. During recovery, he was told that his other knee should be replaced, too. But before he signed up for surgery again, I convinced him to try modifying his walking technique, and to wear less substantial shoes. Three pairs of well-worn minimalist shoes later, he is walking and golfing pain-free, and has lost weight. He says that he feels great, with no hint of pain in the other knee. By realigning his posture, changing his walking technique, awakening the natural springs in his legs, and reducing impact on his joints, he added years of pain-free walking to his life.

  KEEP ON TREKKIN’

  If you need motivation to walk more, try some fun walking accessories. Heart rate monitors are a useful tool to keep track of your effort and your progressing fitness. Movement monitors (such as Fitbit) subtly challenge people to build a record of distance walked and number of steps taken. Try to increase your walking distance to five miles, or ten thousand steps a day. GPS watches can accurately measure distance, but your mobile phone likely has a free app that counts steps and logs distance traveled. Growing numbers of people swear by treadmill desks, and claim (once they are through the short learning curve) that they are more productive overall than when sitting at a desk.

  When hiking or walking in the countryside, you may want to use Nordic poles. Hiking poles give more of your body a workout, and exercise the important “pulling” muscles of the shoulder (most exercise routines, and life activities, engage the pushing muscles). Many fitness programs mix running with walking, and I encourage this, too. As you quicken your cadence and lengthen your stride, your speed and heart rate will rise, and your cardiovascular system will benefit. Leki makes exceptional poles.

  If you’re too busy to dedicate time only to walking, then walk as you talk on the phone, or take someone with you. What’s better than a roundtable discussion—a semispherical one in which you and your colleagues are surrounded, horizon to horizon, by the universe?

  LET THE RETOOLING BEGIN

  In the hospital, walking is the most important part of any post-surgical or disease recovery. Outside of a few unfortunate conditions such as spinal cord injury, the goal should always be to return quickly to walking efficiently and without pain. The principles of posture, balance, body awareness, hip extension, glute strength, and foot strength that we’ll explore in the coming chapters apply equally to walking, and there is no safer or more accessible movement. Its natural flow, and the strength it builds, sets you up to experience relaxed and efficient running.

  DRILLS

  For sedentary people, walking is generally the safest (and easiest) way to start getting into shape. The initial prescription is quite simple: Stand up and begin walking. The next step: Take the next step. Repeat.

  The next time you walk, try practicing these:

  Slow walk. In bare or stocking feet, at home or on a smooth surface:

  Lengthen your spine (envision strings pulling you upward from the top of your head).

  Lean slightly forward from the ankles (imagine a gentle tug on the sternum).

  Land gently on your heel, but feel your weight quickly shift toward your midfoot, as your foot pronates and your toes splay outward.

  Push your foot down and back into the ground (the sensation of pushing along with one foot on a skateboard).

  Finish the stride with propulsion from all of your toes, and load the big toe especially. As your toes bend, your soles will almost turn upward (to be “tanned by the sun”). Your trailing leg will naturally spring forward.

  Listen to your foot strike. You should not hear a slap or a thud.

  Faster walk. Notice that your degree of elbow bend affects your cadence (number of steps per minute). At a nice, relaxed saunter (window-shopping speed), your elbows will be straight and your cadence about fifty to sixty steps per minute. Now bend your elbows to about 45 degrees and watch your step count pick up to sixty to sixty-five per minute. For a real fitness walk, bend your arms to 90 degrees and drive the elbows back from the lower traps (the muscles at the bottom of the shoulder blades), which helps set the rhythm. Experiment. Everyone finds their own slightly different elbow angle that works for fastest, easiest walking.

  Fast walk versus slow walk

  Stand and walk while you work. If possible, work at a standing desk or even a treadmill desk. If you must sit, take every opportunity to stand up, walk, and stretch, such as when speaking with someone or talking on the phone. Ignore the looks of colleagues as you do lunges or swing a leg forward and back and from side to side. They’ll get used to you.

  Walk barefoot in your home. This strengthens your feet and lower leg tissues. Better yet, spend one day a week without shoes (“Barefoot Saturdays”).

  CHAPTER 4

  The World Is Flat If You’re a Foot

  How one runs probably is more important than what is on one’s feet, but what is on one’s feet may affect how one runs.

  —DR. DANIEL LIEBERMAN

  MYTH: Cushioned, supportive shoes of modern design protect your feet and your kinetic chain from injury.

  FACT: There is no evidence that this is the case. Supportive shoes with elevated heels can even “disable” your feet by allowing them to fall out of shape, and can alter your body position and function, setting it up for injury.

  Let’s take a look at the human foot. It’s a physical adaptation—a biomechanical marvel—that is shared with no other primate. Even in medical school, I didn’t fully learn about or appreciate the miraculous way it operates. Understanding how the foot functions by studying its anatomy alone is like trying to learn how a car works by examining its individual pieces.

  The genius of the foot lies in the synchronized interaction of the joints, tendons, muscles, fascia, and nerves, and how they work in service to the rest of the body. This synchrony is controlled by the brain, the spinal cord, and even the local fascial tissue, which receives vital information about the terrain from thousands of nerve endings on the soles of the feet. When this sensing system is in harmony with its moving hardware, the foot becomes an unbeatable, self-sufficient, adaptable—living—machine.

  The foot is also the least understood of the body’s moving parts. In a basic sense, we do know that when force (mainly from gravity) is applied to the
foot, energy is dissipated and deflected through the joints in several different directions. Indeed, the foot is perfectly built for its two most important functions: (1) shock absorption and (2) forward propulsion.

  A partial view of the foot and lower leg. Every foot has twenty-six bones, thirty-three joints, and more than a hundred muscles, tendons, and ligaments, including the body’s strongest, the Achilles tendon. There are four layers of muscles in the soles of our feet alone.

  In addition to working like a shock absorber, the foot stores much of the landing force of every step, then converts it to its other essential function—forward motion. Here are a few of the actions occurring simultaneously in a running foot as the weight of the body falls on it:

  The plantar fascia is the ligament made of tough fibrous tissue that connects the heel to the base of the metatarsals, along the bottom of the sole. As more weight loads onto the foot, the plantar fascia stretches and lengthens, absorbing shock and providing springlike recoil, like a leaf spring on a truck.