Part 1 took up the foot, Part 2 the lower leg and the pelvis, Part 3 the psoas and the diagonal. Structurally, we have climbed from the sole of the foot to just below the ribs.
What this last part takes up runs through all of it: gravity.
Walking is falling and staying upright at once
Part 3 described gait as an inverted pendulum. With the supporting leg as the pivot, the body arcs forward and falls. That fall is the drive for the next step.
Which means walking is a run of falls.
At the same time, a person walking is not falling. Falling with every step, they recover with every step.
Standing and falling are switched between, step by step. What makes walking hard is that the switch is happening every second.
And standing is itself a matter of the relationship with gravity.
The muscles that tire and the muscles that don’t
Stand for a long time and you get tired. Most people know this, and yet it is odd if you think about it.
In hunter-gatherer life people work standing for hours at a stretch. It does not particularly wreck their backs. Standing ought to be, by nature, a thing that does not tire you.
The reason lies in which muscles are doing the work.
Under gravity, two kinds of muscle are at work: muscle that fatigues, called Phasic, and muscle that does not, called Tonic.
The first kind produces movement, and using it makes you tired. It lies nearer the surface of the body and shortens in order to produce force. This is what strength training works.
The second kind supports posture and lies deep in the body. It runs on oxygen and does not tire with continued use. It keeps working without any attention paid to it.
A house makes the comparison clear. The posts hold up the roof for as long as the house stands, and they never get tired. The hand that opens and closes the door does get tired, if you do it enough. Both are inside the body.
Getting tired from standing is a state in which Phasic muscle has taken over work that belongs to Tonic muscle. The wrong muscle has been given the wrong job — the hand that opens the door has been asked to be a post.
The same thing happens in walking. When walking is tiring, when distance is hard to cover, the job of supporting posture has most likely been handed to the muscles of movement.
Tonic muscle has a distinctive property. It takes roughly five seconds to come on and roughly five seconds to let go. Slow in, slow out. Once it is in, it does not know fatigue.
That difference in timing matters in walking. A step lasts less than a second. The support is not switching on afresh with each step; it is on throughout the walk. Only the movement changes over step by step, and the support continues underneath.
Accident, injury, or a strong impact can leave that switch off. When posture cannot be held, loss of strength is not necessarily the reason.
Two directions are needed at once
On the conditions under which Tonic muscle works, there is an important idea in Hubert Godard’s thinking: Palintonicity, or bidirectionality.
Give the body two directions at once, the idea runs, and Tonic muscle organizes itself.
It is often explained with sitting in a chair. The feet meet the floor and the sit bones are supported by the chair. That is the downward direction. At the same time, with those sit bones as a base, the upper body lengthens upward. That is the upward one. When both hold at once, the posture is at its most efficient.
Standing is the same. The lower body feels gravity and heads for the ground: the soles feel the floor, the pelvis receives the weight. At the same time the upper body lengthens toward the sky on that base — the spine lengthens, the crown of the head turns upward.
With only one of them, it does not work. Attend only downward and the body becomes heavy. Attend only upward and you get a state of tension with no ground under you.
A tent is close to it. There is a pull upward and there is what holds it to the ground, and only with both does the fabric take its shape. Either one alone gives you nothing.
The word comes from Heraclitus — the figure of the bow and the lyre, where a shape is held by forces pulling against each other. The name itself is very old.
In walking, the two directions appear in a more complicated form.
The landing foot heads down. It receives force from the floor and supports the body. At the same time the body heads forward and up. It lengthens while falling.
And with every step, which foot takes the downward job changes over. While the left supports, the right is being carried forward. A moment later it is the other way around.
For gait to be smooth is for that changeover not to break. If the body sinks at each handover, or braces to make the handover, the movement comes apart.
The triangle of eye, foot, and inner ear
Back to what Part 1 promised.
Three sensors support posture: vision, the sense from the inner ear (the vestibular system), and the sense from the muscles (proprioception, arriving from the soles). Rolfing treats these three as a triangle with eye, foot, and inner ear at its vertices. The Triangle of Support.
The vestibular system is an organ deep in the ear that detects the tilt of the head and changes in its motion. Being able to tell that you are moving with your eyes shut, when a vehicle swings you around, is this at work.
Proprioception is the sense arriving from muscles and joints, reporting where each part of the body is and how hard it is working. Raise a hand with your eyes closed and you still know where the hand is. That sense.
While you walk, the three work as one. The soles take in information about the floor, the inner ear registers the body’s tilt and motion, vision reports where you are in space. The brain keeps cross-checking all three and updating where the body is.
If one of them weakens, the other two take over. It is what happens to a tripod when one leg is short: the load shifts onto the remaining two.
Failing eyesight, presbyopia, uneven use of the two eyes. In such cases the body mobilizes the muscle sense and the inner ear sense to compensate. In a life built around desk work, the load tends to concentrate on the eyes.
The reverse happens too — situations in which the information from the soles thins out. Hard concrete floors are the classic case. On a floor that is too hard, the soles get little to work with, and the signal reaching Tonic muscle weakens. That is what the tiredness of standing on concrete actually is.
Part 1 said that the foot has 26 bones and 33 joints. That number exists for changing shape, and equally for gathering information. A joint that moves generates information. A foot that does not move is also a foot that does not feel.
And one of the three is unlike the others.
In Rolf Movement training, Rita Geirola made the point that of the three senses, only vision is learned.
A way of seeing is something acquired, and what has been acquired can be changed. Where you look while walking, how wide your field of vision is — these are habits, and there is room to change them.
The sole also receives what lies beneath it
The triangle has a further part to it.
What the sole receives is not only the hardness and shape of the floor. It receives what is underneath as well.
In August 2026 I walked in Shikoku. I climbed Mount Tsurugi, a mountain long used in Japan’s tradition of mountain asceticism, and walked the ridge out to the neighboring peak of Jirōgyū and back. Ordinary sneakers — no boots, no poles. And still I was not especially tired. As I walked, I watched the stones underfoot and at the same time felt how the soles were reading the ground. Nothing was gripping.
That evening I crossed the Iya vine bridge: forty-five meters long, fourteen meters above the water. The slats are set far apart, and the valley floor shows through the gaps.
There my body did the opposite. It shut, and it gripped. I knew perfectly well the bridge was safe. My body followed the fear anyway.
Hours earlier, the same soles had been walking a mountain. The difference was what lay beneath them.
On the mountain, the ground was there as something that would hold me. On the bridge, what was under the soles was a fourteen-meter drop.
When space shows up as something that will support you, the body opens and lets go. When it shows up as something to defend against, the body closes and grips.
This is what the Eye of the Foot is working with. That merely assuming an eye in the sole changes the tone of the pelvic floor is because a change in where perception is placed changes how space appears. Space is not an empty place. It has quality, and it exists as something the body answers to.
Walking is a run of these. With every step, the relationship with the next place to land is made again.
A change in the way someone walks does not only mean a change in how the legs are used. It also means a change in how that relationship is made.
The support is decided before the movement
There is one more idea that reading gait cannot do without.
Just before an arm is raised, the muscles at the back of the leg begin working, to support the body as a whole. Before something is grasped, serratus anterior works. Serratus anterior runs from the side of the ribs to the inner edge of the shoulder blade; the parts attaching to the ribs are arranged like the teeth of a saw, which is where the name comes from. It supports from the shoulder blade side as the arm is sent forward.
Before the movement begins, the support has already moved.
When you pick up something heavy, you change where your feet are before you reach out with your arms. The same thing happens, on a smaller scale, before every movement there is.
In Rolf Movement this is called Pre-movement. Before what you are going to do comes how you are going to be supported.
In walking it happens with every step. Before the foot goes forward, the distribution on the supporting side changes. The preparation that permits falling forward is already in place.
Which is why trying to change how you walk by changing how you place your feet does not work. What has to change is the distribution of support that comes before it.
And Pre-movement does not reach awareness. What can be noticed is the foot, once it has actually gone out. Part of why gait is hard to change deliberately is that the place to change it lies just short of awareness.
What it means to read gait
In Rolfing, a session opens by observing gait and breath. These two are chosen because they are what everyone repeats all day long.
Watching someone walk is not only a matter of speed and stride length.
How long is the stride? Does the heel stay on the floor for a while, or spring up the instant it lands? Is there time in which the toes press the floor? Is there time in which the foot rolls?
What is being watched is whether each phase gets as much time as it needs. Where a phase is short of time, the work of that phase gets skipped: the body moves on before the shock of landing has been fully received, or the foot leaves before the push is finished.
And then the relationship with gravity.
Does the force returning from the floor travel through the ankle, the knee, the hip, into the pelvis? Is the pelvis rotating? Does that rotation travel through the trunk to the shoulders? Is the head sitting on top of the spine?
This is the chain from Parts 2 and 3, followed from the bottom up.
Are the two directions, down and up, holding within each step?
Where is the gaze going? Is the field of vision narrowing or opening?
These are not separate items. Each is an expression of how the body is assembled within gravity.
Walking is also thinking
While you walk, the three senses are continually integrated. The brain keeps updating where the body is in space.
That process of integration is thought to bear on cognition, concentration, and mood. The experience of one’s thoughts coming together while walking, or of a mood shifting, has something behind it.
In the framework of Tonic Function, walking mobilizes coordination, perception, and meaning-making, all of them. It is a matter of the body and equally a matter of how body and brain are connected.
Part 3 said that the iliopsoas sits at the place called the tanden. With that center available, falling forward is safe to do. The state in which falling is permitted and the state in which thoughts come together are probably not unrelated.
Where the Ten Series is headed
Rolfing’s Ten Series is finally aiming at the integration of walking posture.
Sessions eight through ten are called the integration sessions. On the foundation of sitting and standing built up to that point, the work goes toward the whole body coordinating within the dynamic act of walking.
As the sessions progress, walking changes. It got easier. My feet feel as if they stick to the ground. My stride widened on its own. My shoulders started to swing.
All of these are the words that show up when Tonic Function has begun working by itself within gait.
Someone who finished the Ten Series wrote that they would recommend Rolfing to anyone who wants to take a pleasant walk.
A pleasant walk is not a matter of consciously trying to walk correctly. It is a way of walking in which the body moves by itself.
That is what this series has been looking at throughout.
The foot changes shape with every step. What moves the foot is the lower leg, and the leg begins below the ribs. The pelvis turns, the trunk winds, the arms swing. All of it is assembled within gravity.
Not one part of it is something anyone does on purpose.
Rather than trying to make walking better, set up the conditions in which the body can walk by itself. That is all Rolfing is doing.
The series
- Part 1: The Foot Changes Shape With Every Step — How the Arches Are Made
- Part 2: The Problem in the Foot Is Not in the Foot — From the Lower Leg to the Pelvis
- Part 3: The Leg Begins Below the Ribs — The Psoas and the Diagonal
- Part 4: Reading Gait Through Gravity — Tonic Function and Palintonicity (this article)
Related reading
- Why “Standing” Is Not Tiring — The Mechanism of Gravity and the Antigravity Muscles
- Why “Walking” Is Fundamental to the Human Being — The Science of Bipedal Walking, Weight Shift, and Gravity
- What My Body Learned Walking in Shikoku
- Space Is Not “Nothing” — It Is “Something”: A Perceptual Shift Beginning with the “Eye of the Foot”
- Why Good Posture Is Not a Matter of Muscle Strength — Tonic Function and Its Relationship to Gravity
- What Is Rolfing’s Ten-Series? — Three Phases in Which the Body Changes, and the Flow of Each Session
References
Tonic Function, Palintonicity, the Triangle of Support, and Pre-movement are from the work of Hubert Godard.