Measuring walking

Etienne-Jules-Marey-1830-1904

Richard Baker, Professor at Salford University, has recently completed a book “Measuring walking – a practical guide to clinical gait analysis”. He has kindly accepted to respond to my questions.

 What is “Gait Analysis”?

 @RichardBakerUS: Gait analysis is quite simply measuring walking. The term can be applied very widely. At one end of the spectrum it can refer to a simple system based on just one video camera and which might be used by someone in a sports shop trying to sell you very expensive running shoes. At the other end of the spectrum complex systems which incorporate three multi camera systems capable of making measurements in three dimensions and linked up to force plates and muscle activity monitors can be used to plan complex orthopaedic surgery for children with medical conditions such as cerebral palsy.

Is it important to measure and study walking ?


@RichardBakerUS
: Yes, more than one in ten of all people experience difficulty walking 400m. This rises with age to over 50% of all 80 year olds. The corresponding lack of mobility has huge consequences both for peoples health and the economy. It’s really important to understand walking to be able to deliver medical interventions to allow people to continue to walk for longer whatever health conditions affect them.

@bpereiradasilva:What sort of devices and artefact do modern scientists use for Gait Analysis  and Biomechanics studies?

@RichardBakerUS: Modern gait analysis is based around three dimensional optoelectronic data capture systems. These are familiar to most people through documentaries about their use in making animated movies. We place small retro-reflective balls at key positions on the persons torso and legs and then a number of specialised cameras record the position of the markers in 2-d. Computers then use the information to work out where the markers must have been in 3-d. We can then use these coordinates either to drive computer graphic animations and make movies or to give us information about how a patients is moving and plan treatment accordingly.

The technology was originally developed for biomechanics purposes but has benefitted immensely from the astronomical sums of money that the movie industry has pumped into it. In 2005 the two major companies responsible for driving these innovations were both awarded Oscars in recognition of their work.

Does each human have its own characteristic way of Walking?

@RichardBakerUS: There is a wide variety of different patterns of walking amongst humans. Shakespeare has one of his characters recognise another “by his gait” in his play Julius Caesar. Whether everyone’s pattern is unique and characteristic like a fingerprint is simply unknown.

Could it be used to identify people in near future ?

@RichardBakerUS:Several universities and security companies are currently developing video camera based systems to identify people by the way they walk and I was recently asked to act as an expert witness in a case that rested in part upon recognising an alleged criminal from the way he was walking as capture on a security camera. I’m personally quite pessimistic about the technology. We have enough difficulty measuring quite major gait deviations in people with significant medical conditions when we undress them, stick special markers on them and capture images of them form several different angles. It seems most unlikely to me that we’ll ever identify specific individuals when fully dressed with a single camera.

@bpereiradasilva: Some animal can walk a few minutes after Birth.

Why does it take so long for little human to learn walking?

@RichardBakerUS: Most animals have four legs which are much more stable than two (have you ever seen a two legged chair). Of course birds only have two legs but learn to stand very early. I suspect they have bigger feet and lower centres of gravity in relation to their overall size than we do – but this is just a guess.

-have you ever seen a two legged chair ?

-Yes *sir*!

@bpereiradasilva: Parisian designer Benoit Malta has designed a two-legged chair, named Inactivité.two-legged-inactivite-chair-benoit-malta-5

@bpereiradasilva:

Our body is formed, physiologically speaking, over an evolutionary timescale and not over the timescale of technological change or the timescales over which our modern lifestyles can be transformed.

Are we able to quantify how much we should walk to be consistent with our biological reality ?

@RichardBakerUS:There is no doubt that walking and other physical activities have a profound effect upon our physical and mental health. It is very tempting to view this as reflecting our evolutionary origins but I don’t think this has ever been proved and I’m not sure I can imagine how it could be proved. Given this I don’t think there is any way of setting a figure on how much walking we should do. Having said that walking is so rare in modern society that the answer is almost certainly that we should walk more than most of us in the modern world do.

To echo the words of the profit Micah (written down around 500B.C.) what is required is that we “act justly, love mercy and walk humbly with our God”!

@bpereiradasilva: Thank you Richard!

Short Bio

Professor Richard Baker
Professor Richard Baker

Professor Richard Baker, spent the first part of his professional life delivering and managing clinical gait analysis services in major tertiary referral hospitals. He spent seven years at the Musgrave Park Hospital in Belfast and then 9 years at the Royal Children’s Hospital in Melbourne. Whilst in Melbourne he was the founding Director of the Australian National Health and Medical Research Council Centre for Clinical Research Excellence in Clinical Gait Analysis.

 

measuring-walking

Resources

Gait analysis is the systematic study of animal locomotion, more specifically the study of human motion, using the eye and the brain of observers, augmented by instrumentation for measuring body movements, body mechanics, and the activity of the muscles

Read more on Wikipedia.

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