-By
Abhijeet Mahato
Indian Institute of Technology, Kharagpur

There is a collection of involuntary actions that our body carries out without we being aware of it such as breathing, blinking of our eyes, respond to stimuli, etc. You know one such semi-voluntary action that doesn’t require much of your conscious effort is walking. But do you know among all 4 limbed mammals, we are the only permanent bipedal (i.e. use only two limbs for primary motion)? So, what is bipedalism?

Bipedalism means locomoting (e.g., walking, jogging, running, etc.) on 2 legs. In this article, I will highlight the important points in brief about what are the impacts of bipedalism on humans. So, let’s dive into the topic.

Human anatomy successfully defies the central principles of mechanical engineering. In most manufactured devices, such as cars and ships, the bulk of the weight is concentrated in the lowermost part to achieve maximum stability. But in humans, there is an irregular distribution of mass throughout the body.

Most importantly, just because of this biological complexity a fully functioning bipedal robot that can mimic humans physically is yet not achieved. The major difficulty is in achieving an automatic stability generation system. The alternative of the involuntary response system towards the tendency of falling in humans is still being a major challenge in the field of robotics engineering.

Major Adaptions for Bidepalism

The conversion of humans from quadrupedal to bipedal witnessed the following changes with the course of time. –

  • The feet evolved to have an enlarged heel in order to support the entire body weight. This provided stability and the knees got shrunk inwards.
  • The lengthening of the hindlimbs (legs) compared to that of the forelimbs (hands) and the shrinkage of shoulders and rib cage.
  • The enlargement of hip joints to support the greater amount of body weight, along with a shorter and broader shape.
  • The vertebral column took a forward bend in the lower region and a backward bend in the upper region. In simple words, “it evolved from a linear shape to an S-shape.”
  • Brain size increased significantly throughout human evolution. While the muscle strength and density shifted from the forelimbs to the hindlimbs.
comparison skeleton of bipedalism
Skeletons of Human and Ape

Positive Impact of Bipedalism

Since the evolution took place in this direction, it obviously had its own set of advantages. Out of which some are listed below.

  • Better field of vision: As humans achieved got upright their head rose and now had a wider and longer range of visibility.
  • Free Forelimbs: Humans were able to achieve various other tasks such as holding tools and gathering resources.
  • Energy Efficiency: It minimizes the energy expenditure of movement and allows quick positional changes in all directions. It also enables rapid acceleration and deceleration in emergencies
  • Faster movements: Long hindlimbs provide large strides.

Walking upright freed the hands for carrying and manipulating tools,” says Chris Stringer, a leading anthropologist at the Natural History Museum in London. “It allows longer-distance walking and, eventually, endurance running. Ultimately, it may have been a key step that led our ancestors’ brains to grow.

Negative Impact of Bipedalism

Apart from all the benefits, it also had some negative impact as well. Out of which some are listed below.

  • Loss of ability to climb trees: With the adaptions climbing trees are not as easy as it has been earlier. 
  • Improper Balance: Because of a higher center of mass and lesser base area, the chances of toppling and falling have increased.
  • Back and knee aches: The pressure on the pelvic, knees and feet gives rise to various problems in the process of aging.

Importance of correct walking stance/posture

You must have come across lots of articles, news reports, and videos emphasizing the proper posture of walking from a health perspective. But, I am here talking about the importance of the correct posture from the evolutional adaptations point of view. Our entire body weight is now concentrated on the pelvic region and supported by the knees & feet. At our pelvic, the entire body weight is exerted through the S-shaped vertebral column.

Now, it is important for us to understand that our skeletal and muscular evolution was according to an optimum posture. But, today we somewhat don’t even think or care about it.

However, due to this, even a slight change in the posture of walking or even standing actually does a lot of harm to us. It may not be evident at the very moment, but in the long run, it harms us. Due to the wrong posture of standing/walking, there is a huge chance of development of hunchback, arthritis and back problems in older people with due course of time.   

So, below is a YouTube video by the channel Rehab and Revive, in which Dr. Justin C. Lin explains about the correct and beneficial walking technique.

Credits: Rehab and Revive

So, what are you thinking? Its time to correct your walking stance in order to stay healthy and most importantly, to support the true purpose of our evolution to bipedalism.

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