1. WELCOME:

Dear friends welcome to my Home Page on Human Posture. My name is Selvaraj, I am from India, and I have been interested in the subject of Human Posture for the last 25 Years – ever since, I came across a book on the subject by Dr. Wilfred Barlow.

2. THE BOOK BY DR. BARLOW

Fig 1: Dr. Wilfred Barlow, a Rheumatologist, did extensive research on human posture and authored the Book, The Alexander Principle. His book suggests ways to correct your posture and highlights medical problems that can arise from faulty posture. The medical problems discussed in Dr. Barlow’s books are Rheumatism, Arthritis, Cervical Spondylosis, Back Pain, Breathing Disorders, Stress Disorders and Gastro-intestinal Disorders. Dr Barlow estimates that 99% of adults will have faulty posture (more on this later).

3. INTRODUCTION:

Speculation on human posture forms part of our philosophical, social and cultural heritage. Human beings have pondered this subject from ancient times. In India, around 400 BC, the discipline of Yoga took shape to help invigorate the body, calm the mind, and to develop ones hidden mental and spiritual powers. Over the past hundred years, many other disciplines such as Chiropractics, Osteopathy, Rolfing and The Alexander Method of posture correction have evolved to help individuals cope with their posture. You can find out more on these subjects in the Internet.

In this presentation we look at human posture from a different perspective, the perspective of an Engineer, deviating from traditional more intuitive methods used to understand the problem. The bones and muscles in the body form a Mechanism, controlled by the Human Brain. This composite system can be explored using Engineering Principles to facilitate better scientific understanding of the problem.

4. THE HUMAN MUSCULOSKELETAL SYSTEM:

Fig 2: The human body is a mechanism (Picture, Adam.com)

	Fig 3: The human Musculoskeletal System can be compared to a system with struts and guy ropes. When engineers design such systems, the guy ropes are spaced well away.
	Fig 4: In the human body, the guy ropes (muscles) are closely spaced making the system very fine-tuned and critical.

The bones and muscles in the body – which complement one another, and act in unison – form the musculoskeletal system. This system is very, very complex and very critically put together. It is so complex that so far no computer model has been made to explain human movement in a satisfactory way.

Let us find out why the design of the musculoskeletal system is so complex and critical. In Fig 3 we see a structure which engineers design, consisting of struts hinged end-to-end and supported with the help of guy ropes. Engineers design such systems with great care, spacing out the guy ropes to make the structure strong and stable. The human body can be compared to this system by visualizing the struts as bones and the guy ropes as muscles. In the human body however, the guy ropes are very close together, Fig 4, making the structure very critical and prone to POSTURAL COLLAPSE.

5. POSTURAL COLLAPSE:

Fig 5. Postural collapse

What is Postural Collapse? Postural Collapse is a condition where the musculoskeletal system is so badly deformed that it is no longer possible to easily revert to the original balanced state. In Fig 5, we see a system of links (bones) controlled by ropes (muscles). In the lower extremities the joints have moved beyond their safe limit causing a group of muscles to be over-contracted. When muscles are over-contracted, over a period of time they stop functioning in a normal way, and cannot readily be relaxed to their original length. (The distortion visualized here will also significantly alter the orientation of bones and muscles higher up, effectively distorting the complete structure!)

As a consequence of this distortion, it is no longer possible for the muscles to contract powerfully, since their natural functioning will by inhibited by the brain to protect the integrity of the body. What appears to be a local weakness, will in reality distort and weaken the whole body - it is a condition that cannot be easily corrected.

6. HOW DO WE KNOW THAT PEOPLE COLLAPSE THEIR POSTURE?

Fig 6: Distortions of the neck. A. Neck collapsed forward. B. Head back, Upper neck forward, lower neck back. C. Head pulled back. D. Lower neck collapsed out of sight. E. Overstraightened neck. Fourth vertebra slipped forward on fifth. (From The Alexander Principle, by Dr. Wilfred Barlow).

It is difficult, with our available knowledge, to comment on people’s posture by looking at them externally. It is necessary to look at the internal orientation of bones and muscles. The orientation of muscles unfortunately, cannot be determined readily due to non-availability of suitable sensing equipments. The orientation of bones on the other hand can be studied with the help of X rays. Here too, faults are readily discernable only in X rays taken of the Cervical Vertebrae, as seen in Fig 6. It is not too difficult to visualize that faults shown in the figure will be very difficult to correct.

Studying Fig 6, we can make the following additional deductions. One, if the bones are distorted in this way, the muscular system must be similarly distorted. Two, It is unlikely that distortion will be localized, similar distortions must exist in the rest of the body - even though existing sensing devices may not readily allow us to visualize these distortions. Three, because of the phenomenon of postural collapse, posture can only be defined as being very good or very bad, it is difficult to define something in between. Four, postural collapse is bound to alter our external appearance (we do not have the tools at present to understand from our external appearance, the full gravity of the problem – it will also be inconsiderate to tell a person that his external appearance indicates postural problems; all of us value our external appearance)

A book is available ( 294 pages, 190 figures) which discusses this subject in greater detail. Please contact sraj99@gmail.com

Discuss: humanposture@yahoogroups.com

Paper : Paper published in Aerospace Mechanisms Symposium 2005, Bangalore, India:

‘ The Performance and Stability of Mechanisms in Living Organisms’

If you wish to have an E Copy please contactmailto:sraj99@gmail.com

Blog: humanposture.blogspot.com