The Aches and Pains of emergent system properties

Posted: April 6, 2012 in Diary, Systems Theory
Tags: , , , , , , , , ,

I have carried an ache in my left shoulder for about 4 days now. Yesterday, I decided to get it looked at. I couldn’t get an appointment yesterday, but managed one today – Good  Friday – unusual for a bank holiday (public holiday in the US).

What has this got to do with system’s theory?

Emergence” is the concept that behaviours emerge when different  systems are integrated or joined together. In this case systems could be, hardware or software components, a sub-system built from these components or even sociopolitical systems such as a country’s welfare state or voting system.

Giant's Causeway in Northern Ireland is an exa...

Giant's Causeway in Northern Ireland is an example of a complex emergent structure created by natural processes (Photo credit: Wikipedia)

Each of these systems or components has an inherent (and in most cases, known) behaviour. Emergence can occur when these systems are coupled together. In some circumstances its easy to predict the resulting behaviour such as when an oscillating system is joined to an amplification system – the oscillation gets bigger. In that case the resulting behaviour is probably desired. The designer intended to make the oscillation bigger for what ever the application – radio transmission, louder music, etc.

But even in a system such as the oscillator/amplifier combination, emergence can bring a number of unwanted emergent properties such as distortion or feedback. These can be remedied by adding a further system to filter out distortion or control unwanted feedback signals. This result of coupling is well-known in the craft field of electrical engineering and is generally considered during design. However, in evolving systems or large-scale, complex systems it is harder to predict. This is where the discipline of Systems Engineering looks specifically at system issues such as emergence.

 

So what’s that go to do with my back pain?

Last week, I wrote about my hike up into the Brecon Beacons from Pencilli. On the descent, I noticed a sharp pain in my left hip. I mentioned this to the therapist today, wondering if it were connected. She immediately started focusing on my right side and found that I had a partially immobile right SI joint (where the pelvis connects to the spine). She explained that the pain in the left hip was probably due to the body placing extra stress on the left knee as the brain attempted to level-up the pelvis. This in turn causes the IT Band (which is a piece of fascia tissue that runs between the knee and the muscles around the pelvis) to become inflamed by friction as it crosses the hip bones.

As the body has a natural aversion to pain, this causes muscle groups to tighten around the painful area to protect it. The tightening of these muscles caused the pulling of other muscle groups under the arm and in turn, the rhomboid muscles that sit under the shoulder-blade to tighten.

The body has a huge amount systems which it tries to keep in a balanced state (called homoeostasis) through everything we put it through. Generally, this is governed by feedback supplied by various biological sensors around the body and control mechanisms relayed through the nervous system.

In this case, a failure in one part of the body’s structural system, caused a pain signal in another part of the structural systems which led to body triggering a protection response which results (days later) in a painful condition elsewhere in the body.

The human body is a wonder of engineering and is a fantastic example of systems coupled together. Sometimes it doesn’t turn out how we would like, but its pretty good most of the time!

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