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The foot: the human advantage

I do not hide it at all. My favorite muscle is the flexor along the hallux. It is the muscle that allows flexing of the big toe. It’s the muscle of propulsion. It is this muscle that makes it possible to take the step. It is also the muscle that allows the activation of the posterior chain, so important in physical conditioning!

To know that it is this same posterior chain that allows us to stand up, is not it interesting and logical to note that, according to a recent study (http://www.pnas.org/content/early/2018 / 08/07/1800818115), it seems that the big toe is one of the last parts of the foot to evolve? Researchers have shown that the big toe has reached its current shape only much later than other toes. Peter Fernandez states that “the big toe could still be used to grasp, because our ancestors spent a good deal of their time in the trees, before becoming fully an earthly species.”

He goes on to say: “The modern human has seen the stability of the joint (foot) increased when the orientation of his big toe has changed to allow walking. At the same time, the foot lost the agility associated with its simian and arboreal origins. Why did we come to walk? Science seems to accept quite broadly the theory that it is climate change that has reduced forest cover. We had to descend to the ground to feed ourselves, which would have led us to recover and finish on two legs. True or not, it is true that moving on two feet requires less energy than walking on all fours. It would be 4.4 million years ago that we started walking upright.

Namely, at that time, that the station erected and the walk and the resulting race are engram in our genetic makeup, would not it be worthwhile to improve these strategies. This is obviously the goal of the posturologist!

The foot: the human advantage

I do not hide it at all. My favorite muscle is the flexor along the hallux. It is the muscle that allows flexing of the big toe. It’s the muscle of propulsion. It is this muscle that makes it possible to take the step. It is also the muscle that allows the activation of the posterior chain, so important in physical conditioning!

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Dopamine, serotonin and gait

Most of us, when thinking about dopamine, serotonin or neurotransmitters in general, think of behavior, for the most part. Yet, if you tend to agree with most experts in the field of functional neurology, you can appreciate that behavior is a derivative of how the brain has and is wired. That being said, the brain’s most primitive reason for wiring is to mange sensory-motor experiences that lead to, amongst many feats, standing upright. Read more

To be… to walk

Locomotion is one of the most thoroughly studied behaviors in the animal kingdom. It is Mahler, a psychoanalyst that has stated that the onset of voluntary locomotion represents the “psychological birth” of infants.

The acquisition of crawling (typically the first locomotor skill) dramatically changes the relation between the infant and the environment. It is from this point on that the infant can find challenges and problems to solve. The infant can explore the environment and operate at will (Gibson, 1988).

Exploration thus provides new perspectives and it creates novel experiences that can drive changes in a family of different psychological phenomena.

So how is fear management and gait development possibly related?

Experience with locomotion seems to be a factor in the onset of weariness of heights.

Mothers notice two interesting phenomena related to drop offs.

First, there is a period after the onset of crawling when their infants would plunge over the edge of a bed, off the top of a changing table, or even off the top of a staircase if she were not extremely vigilant.

Second, within 2 to 4 weeks of crawling onset, infants will avoid drop offs. These maternal reports are highly consistent (Campos et al., 1978).

Although perception of self-movement has traditionally been relegated to information from the vestibular and the somatosensory systems, visual proprioception is so powerful that a standing 13-month-old infant will fall down when exposed to optic flow in a moving room (Lee and Aronson, 1974).

Visual proprioception is a powerful source of information for postural stability and instability.

When the infant moves voluntarily, the head and eyes consistently point straight ahead (Higgins et al., 1996). As this takes place, when the infant navigates the world, it becomes important to segregate information about environmental features from information about self-movement so as to steer an appropriate course and maintain postural stability.

How we have learned to walk seems to be at the core of how we developed, as a whole. It is by learning locomotion that we have had to face challenges and mange fear. Could it be that, if we did not crawl and walk on all four, we could be less equipped to face the challenges of the day?