Saturday, November 28, 2015

Meditations on the Hip Joint and Pelvic Girdle - Max Popov (2011)


Max Popov


On Stability - Introduction to the Hip Joint and Pelvic Girdle

The standing human body is stable  when its line of gravity falls within its base of support; namely, our two feet and the area between them. Stability becomes increasingly precarious as our center of gravity nears the edge of our base. When the line of gravity falls outside our feet, we fall.

On Standing Up - Bent-Leg Hip Extension and Hanging Knee Raise

If we think about the mechanics of rising at all, it's probably because our ability to stand (or the ability of someone close to us) has been impaired or even lost. During the weight-resistance yoga session, when we reflect on what it means to be human, we consider how standing up is a critical aspect of not only our daily life and the evolutionary development of our species but also the biological development of the individual.

On Arrested Falling - Hip Abduction and Hip Adduction 

While not an act of derring-do, like that of a tightrope walker crossing a high wire, the simple of walking on the ground is, when you think about it, an amazing balancing act all the same. A rhythmical movement in which the center of gravity is swung forward, human bipedal gait places us in peril at every step.

By cultivating gladness for those who are happy, compassion for those who are suffering, delight in those who are kind-hearted and disregard for those who are selfish and mean, we habitually remain calm. - Patanjali

An object's center of gravity - the place where the Earth's gravity is considered to act on the object - is the point at which its mass is concentrated. Located within the object (say, a hard-boiled egg, a baseball bat, or an automobile), but not usually coinciding with its geometric center, the center of gravity can be approximated by finding the object's balance point, the place where the object can be twirled about (at least theoretically) on one finger.

In the standard anatomic position (standing upright with the palms of the hands forward), the human body's center of gravity - the point around which the body's mass is evenly distributed - lies approximately just in front of the second sacral vertebra. (The precise location depends on our height, weight, and frame - our unique proportions.) If our body is fixed in this position, then no matter how it's angled to Earth - whether standing upright, leaning, lying, or standing upside down - our center of gravity doesn't change. (Picture the prone, unbending silent movie comic Buster Keaton, quiet and dignified, seemingly gliding through the air as he grasps onto the back of a moving cable car.)

What produces a new  center of gravity is movement of a body segment (say, lifting a leg to give a ball a hard kick). The line of gravity - the action line of the force of gravity on an object - is like a plumb line attached to the center of gravity. Regardless of the orientation of the object on Earth (including its atmosphere), the line of gravity is always vertically downward toward the center of the Earth. 
For an object to be stable, the line of gravity must fall within the object's base of support. The standing human body is stable when its line of gravity falls within its base of support: namely our two feet and the area between them. Stability becomes increasingly precarious as our center of gravity nears the edge or our base. When the line of gravity falls outside our feet, we fall.
In everyday life, of course, we seldom stand rigidly for long. 
We move.
               And we're moved.

Gravity is the most consistent external force encountered by the human body, but there are others: objects that we're wearing, carrying, or using pull on us; strong winds, ocean waves, and other natural elements buffet us about; and people push or pull us. We can increase our stability (give our line of gravity more freedom to move without falling outside its base of support) in response to these external forces by lowering our center of gravity (by bending our knees) and/or by making our base of support larger (by widening our stance or by relying on the support of a cane, a walker, crutches, a ballet barre, or the like), heavier (by performing strengthening exercises for the lower body, including our hips).

The hip joint consists of the ball-like head of the upper leg bone (the femur) and the hip socket (acetabulum) of the pelvic girdle. The pelvic girdle consists of the right and left pelvic bones joined together posteriorly by the sacrum (the triangular bone at the base of the spine) and anteriorly by the pubic bones.

Although favoring stability over mobility, the hip joint is the second most mobile joint (after the shoulder joint) in the body. Routine movement of the hip joint usually involves movement of the pelvic girdle. For example, in walking, hip flexion (lifting the leg forward) is accompanied by pelvic girdle forward rotation (anterior tilt), and hip extension (bringing the leg backward) is accompanied by pelvic girdle backward rotation (posterior tilt).

Weight resistance yogins faithfully strengthen the four major groups of hip muscles: 
1) the flexors, which move the upper leg straight forward and up;
2) the extensors, which move the upper leg straight backward and up;
3) the abductors, which move the upper leg to the side and away from the midline; and 
4) the adductors, which move the upper leg from the side toward the midline.
Most of these muscles also act as external rotators (which rotate the upper leg away from the midline), or internal rotators (which rotate the upper leg toward the midline).    

As we age, we come to consider the importance of having strong and healthy hips. As we've seen, the hips (along with the other segments of the lower body) counteract the pull of gravity and the effect of other forces and allow us to be ambulatory, as well as act as a pillar that supports the trunk and head. But we who practice weight-resistance yoga also recognize hos an embodied practice that includes exercises that strengthen the hips, perhaps especially in their role as stabilizers, can help change our behavior - which means to say, shape the self.

Many of us are ruled by uncontrollable patterns of behavior that make us unhappy. Yet they seem to us to be rational responses to people around us and events out of our control. Put upon, we become irritable and fly off the handle. Feeling slighted, we sulk, nursing the desire to get even. Feeling unappreciated, we constantly seek acknowledgment. When expectations go awry, we lose heart or turn cynical and pessimistic. Our center is unstable. Through working on hip-strengthening exercises, weight-resistance yogins attain a physical stability that over time comes to correspond to an inner stability -- a stability that isn't a steady condition impervious to the world but an engaged response to the world. We embrace others. We seek their embrace. Yet we detach ourselves from their crazy talk. We retain our equanimity. When we're "pushed" and "pulled" by sudden, unforeseen events, large and small, we're not upended. We receive good news and bad news, success and failure equably. We remain calm and undisturbed. Sometimes we teeter. But grounded in the earth (through accommodation with gravity) and yearning for the heavens (through resisting gravity and standing upright), we soon move back to our vital center.

To know is accordingly the ability to stand in the manifestness of things that exist, to endure them. Merely to have information, however abundant, is not to know. -- Martin Heidegger

An Introduction to Metaphysics

Bring a leg back. This movement -- hip extension -- is performed by the large gluteal muscles, which make up the buttocks. Feel your buttocks. Although layered over with fat, the gluteus maximus, which forms most of the muscle of the buttocks, is easily palpable. That's because it originates on the posterior spine and pelvis and inserts on the upper leg. Bring the leg forward and up. This movement -- hip flexion -- is primarily performed by the iliopsoas, which lifts the leg beyond the normal standing position. Moving obliquely from the small of the back through the pelvic bowl to attach at the front upper leg, the iliopsoas, although large, is palpable only in the emaciated or in the thin who relax their abdominal muscles. These two dissimilar and opposing muscles -- the gluteus maximus and iliopsoas -- work together sequentially, sometimes in an alternating rhythm, to perform a variety of motions that require strong anterior/posterior action of the hips. They contract during jumping and leaping. They provide action to propel the body forward when walking up an incline, such as a ramp or a hill. When climbing stairs, while the gluteal muscles work to shift the body's weight over the supporting leg, the iliopsoas works to lift the swinging leg. Both muscles play critical role in running, not only in propelling the body forward but also in stabilizing the body to keep it from pitching over.

Although they aren't strongly contracted during ordinary walking, the gluteal muscles and iliopsoas are strongly brought into play in another common daily activity: standing up from sitting. In general, we prefer sitting to standing. The act of sitting down, especially as we get older, is a a pleasurable activity. It sometimes produces a sigh of relief. We're equipped for sitting. Compared to ape buttocks, human buttocks, human buttocks are quite large. Apes sit on their ishial tuberosities, sitz bones, which protrude through their fur; we're cushioned by prominent rounded buttocks. Aristotle observed: The posterior bottom of the trunk and the parts about the upper legs are peculiar in man as compared with quadrupeds. Nearly all these latter have a tail. But man is tailless. He has, however, fleshy buttocks, which don't exist in quadrupeds. His thighs are also fleshy. There is one explanation: of all animals, man alone stands erect.

Standing causes no fatigue to quadrupeds, and even the long continuance of this posture produces in them no weariness; for they are supported the whole time by four props, which is much as though they were lying down. But for man, it's no easy task to remain for any length of time on his feet; his body demands rest in a sitting position. This, then, is the reason why man has fleshy buttocks and thighs. But sooner or later, stand up we must.

In fact, rising to a standing position from a sitting position is one of the most critical activities of daily life. Just consider early morning before we go out in the world: we get out of bed, get up from the toilet seat, and leave our chair at the kitchen table after breakfast. Rising from a seat involves four phases. In the first phase, to initiate momentum for rising, we lean forward as we fix our upper legs, shifting the center of gravity of the trunk over our feet. In the second phase, in order to transfer momentum to the whole body, as we leave the seat we slightly bend our knees. In the third phase, we begin to straighten the knees, hips, and trunk as the body rises. In the fourth phase, we stabilize the body in the full upright position. The first and second phases recruit the iliopsoas; the third phase, the gluteal muscles; and the fourth phase, both. If we think about the mechanics of rising at all, it's probably because our ability to stand (or the ability of someone close to us) has been impaired or even lost.

During the weight resistance yoga session, when we reflect on what it means to be human, we consider how standing up is a critical aspect not only of our daily life and the evolutionary development of our species but also the biological development of the individual. In first standing up without support, the child has no concern for security. Failure -- falling down -- doesn't discourage the child one bit. The forceful urge to get up, to resist downward-pulling forces -- while in a state of precarious balance! -- overcomes any fear.

"In getting up," observes German phenomenological psychologist Irwin W. Straus, a child "gains his standing in the world. The parents are not the only ones who greet the child's progress with joy. The child enjoys no less the triumph of his achievement." There's no need for parental attention, yet applause. Fitness trainers regularly use the parenting model of "providing positive feedback" with their clients. This training philosophy of "bolstering self-esteem" fosters an inappropriate relationship: come semblance of parent/child and even lover/beloved or sadist/masochist.

In contrast, yoga teachers, including weight-resistance yoga teachers, don't shore up self-esteem and provide positive reinforcement. They don't get caught up in praise (and its implicit threat: the withdrawal of praise -- which means to say, blame. They don't provide motivation by cajoling, scolding, or goading students. They don't chitchat; there's too much to attend to. They simply demonstrate correct form to students and then correct students' form by making adjustments, thereby aiding students in moving deeper into an exercise. [Sounds a lot like a good weightlifting coach, don't it.] Of course, weight-resistance yoga teachers do much else. They set a tone -- from mindful to motivational -- for the session. They help us recognize how our movements reveal our habitual thoughts, emotions, and attitudes, so we can discard those that interfere with our spiritual path. They aid us in becoming fully absorbed in our movements as a means of accessing realities beyond everyday life. But no matter how much they guide us, we always know that it's through our own self-discipline that our life is transformed and that it's only we -- in part through our reverent and upright posture -- who can open ourselves up to the ground of Being.

In yoga we do well to avoid too much of the idea that we are bound to the earth, even physically. The earth pulls us towards it by gravity, but we also pull it upwards to us, also by gravity. We thus have a share of the original power, and when walking . . . we do to some extent float. -- Ernest Wood.

Between five and six million years ago, a new type of primate evolved in Eastern Africa -- one that walked on two legs instead of ambling along on all fours with its front knuckles to the ground. Bipedalism was literally the first evolutionary step that divided hominids from apes. To develop the ability to walk upright, the anatomy or our ancestors underwent complex changes that shifted the upper body over the pelvis and the lower body more directly under the pelvis. (Recent research has shown that some aspects of human anatomy may have evolved in order to accommodate running, not walking.) Among the changes that took place was the angling inward toward the body's midline of the thighbone (femur) as it slopes toward the knee. In apes, the femur runs straight down from hip to knee, which accounts for their boxy, side-to-side, swaying gait. Humans are wider in the hips than through the knees, which improves our balance. As is our want, we've used this mechanical advantage to individualize our gait.

As you walk down a sidewalk in a shopping area in springtime, notice how the sway of people's hips varies, depending on their frame, age, speed, and mood, as well as their status and personality. As Mabel E. Todd, one of the pioneers of bodywork [specifically Ideokinesis], observed in 1937: "Watch any man as he walks down the avenue, and you can determine his status in life. With practice, a finer discernment will have him placed socially and economically, and with a fair idea of his outlook on life."

A classic study of physiology and the effect of psychological processes on movement that has a
mind/body approach.

"The ability to improve a pattern of support and movement for the reduction of stresses comes, not through the development of bulk and power in individual muscles, but from the study and appreciation of the human body as a weight-bearing and weight-moving structure." (Page 33)


Even those of us with little discernment of body language have noticed (if only in some vague way) that a person's gait is expressive of his or her emotional make-up. A genial disposition, a touchy temperament, strong or weak character, a pinched or expansive personality, meek or overbearing behavior are all, we'd agree, expressed in gait. But whatever a person's unique gait, the mechanics of his or her walking are the same. Walking consists of a swing phase and a support phase. Slip behind a woman wearing tight jeans and take a dispassionate look, if possible, at the changes in the position of her hips made with each step. (Because women's hips are generally wider than men's, a woman's gait is more pronounced, making it a more advantageous subject of study.) Note that when her right leg lifts off the ground, during the beginning of the swing phase, she's standing on her left leg. The right side of her pelvis is unsupported, leaving her vulnerable to tipping over to the right. What keeps her from falling over?

During the swing phase, the abductors (the group of hip muscles that attach to the upper, outside part of the leg) of the supporting (left) leg contract to oppose the tendency of the pelvis to drop on the unsupported (right side). At the same time, the adductors (the group of hip muscles that attach to the leg on the inside of the thigh) of the swinging leg contracts to shift the pelvis over, moving the upper body weight over the supporting left leg. The right leg lifts (bends at the knee) and then straightens (extends at the knee). The swing phase ends as the heel of the right foot is placed on the ground. When the whole foot is placed flat on the ground, the hip adductors and abductors of both legs stabilize the pelvis. This support ends when the heel of the trailing (left) leg is raised in push off. 

While not an act of derring-do, like that of a tightrope walker crossing a high wire, this simple act of walking on the ground is, when you think about it, an amazing balancing act all the same. A rhythmical movement in which he center of gravity is swung forward, human bipedal gait places us in peril at every step. As we've seen, the whole weight of the body rests for a short time on only one leg, destabilizing the body, thereby putting us at risk of falling -- until the leg brought forward reaches the ground, once again rescuing us from the threatened fall. 

As phenomenological psychologist Erwin W. Straus observed: "Human gait is, in fact, a continuously arrested falling." For this reason, it can be said that walking is an assumptive act: upon taking a step, we take for granted that the leg brought forward will ultimately find solid ground, and that we won't fall. We might trip over an unseen obstacle or unevenness of ground. Somebody might knock us over. Our weak or frail bones might precipitate a collapse. But, by and large, we're not anxious when we walk. Most of the time, our experience of walking is pedestrian: we move from Point A to Point B without any worries. Which is all the more reason to keep the hip joints strong and healthy. 

A marvel of locomotive engineering, the hips lose their effectiveness as we age. By strengthening the hip muscles -- in particular, the two hip abductors, the gluteus medius and gluteus minimus, we can to a great degree retain the spring of youth in our step. This strengthening will allow us to continue putting one leg in front of the other to ambulate without giving a thought to it.

Not that attentiveness to walking is a bad thing. Hatha yoga praises the body -- not so that we can display it as a proud possession [after all is said and done you only rent the thing anyhow], but so that we can move with steadiness, ease, and strength when needed. Without a fit and healthy body we cannot know bliss. But the physical conditioning aspect doesn't benefit only the periods set aside from everyday life for achieving altered states or for enjoying the self-induced efforts of training; it also makes possible transportive experiences during everyday life, such as walking down a street, perhaps on one of those days when it's lightly raining and the fragrance of trees is strong. As we effortlessly stroll along, we turn our attention to our stride: the swing phase and the stability phase feel so secure and coordinated and elegant, they seem to be acting through us. By this I mean that we can identify the doer. We don't make decisions about taking steps. They just happen. "We" are no more doing the walking than "it" is raining. There's no will to move or submission to being moved. There's just serenely complete walking.

And wouldn't it be something to apply that to your lifting.      


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