Balliol Talk – 18th November 2016
“Oxford’s Contribution to Motion Analysis”
Tom Shannon PhD
Dear Colleagues and friends,
I am reminded that our own Shakespeare proclaimed that: Brevity is the Soul of Wit, but then went on to write plays that lasted 4 ½ hours. In being given the honour to speak to you it is in the fulsome knowledge that I am keeping you from the many delights of the first course so I choose to follow the preaching of the great Bard rather than his practice, most particularly if I hear bread knives being quietly sharpened for an et tu moment within these fine walls.
After being kindly asked to speak on “Oxford’s contribution to motion analysis” caused me to revisit this whole topic so if you don’t mind I have twisted it slightly to become “the musings of an interested incomer” as I try and navigate along the path of our common journey and our hugely important story.
The first photograph was taken in France in 1826 heralding the opportunity to accurately record an instant in time, followed just short of 50 years later by the great Californian landscape photographer, Eadweard Muybridge winning a bet set by Governor Stanford on describing the gait of horses at the full gallop; giving him the funds and life-long obsession to create his seminal yet qualitative images of human and animal motion. Étienne-Jules Marey built upon Muybridge’s work by dressing subjects in black clothing where inter-joint segments were clearly identified and multiple gait cycles captured on a single photographic plate. Then during the closing years of the 19th century Professor Braune and his student Fischer applied Geissler tubes to limb segments, flashing 26 times/second, photographing subjects walking in total darkness using open lenses from four viewpoints. Following 8-10 hours of data collection per subject, they achieved a successful tri-dimensional kinematic analysis for the first time but it took them 12 months to complete the calculations. I can only imagine what our health & safety experts would say today if they observed the high voltage cable attached to the top of the subject’s skull and was experimental artefact a factor worth considering?
In the 1940’s Eberhardt and Inman in the US, photographed a subject walking in front of an open lens of a camera fitted with a rotating slotted disk while carrying small light bulbs attached to the hip, knee ankle and foot. The result was a series of dots at equal time intervals that had to be laboriously connected to estimate joint angles. Dr Mary Pat Murray, a Wisconsin physiotherapist, attached reflective targets to specific anatomical landmarks with the subject being photographed in the sagittal plane whilst illuminated by a strobe light. She successfully used this approach to describe both normal and pathologic gait. The approach still required time-consuming manual measurement and without any insight into lower limb joint rotations in the transverse plane was of limited practical application. Film was used extensively in the period before the mid 1960’s but did not achieve wide clinical acceptance as a routine approach. In 1967, Dr Hans Furnée in the Netherlands started experimenting with the automated recording of reflective marker positions to capture multiple joint angles using video technology and pulsed light. Such was a portent to our electro-optical future except that these measurements were of a cat on a treadmill.
Researchers including Dr David Winter in Canada, Pro Juventute Foundation and Politecnico di Milano with significant contributions by Ferigno, Pedotti and Capozzo were also starting to investigate the use of these emerging technologies but our story now moves to Strathclyde University in Glasgow and Professor John Paul. He had been tackling the question of hip joint loading during walking that needed urgent resolution as orthopaedic surgeons began replacing worn and fractured hips joints with artificial prostheses which were either failing, loosening or damaging surrounding bone. John Paul assembled a still recognisable gait laboratory using sagittal and transverse plane cine-film cameras, a home-made force plate and electromyography. He established that during vigorous walking loads peaked at almost three times body weight but continued to be constrained by technological deficiencies in the manual approach so in 1972 tasked two of his PhD research students, Michael Jarrett and Brian Andrews (interestingly one of my doctoral supervisors) to create an automated system using video cameras, mini-computers and retro-reflective markers. Over the next five years John and his students improved and replicated their system for installation in Glasgow, Dundee and Oxford. The university Departments of Engineering Science and Orthopaedic Surgery joined in the collaborative effort with one of John O’Connor’s doctoral candidates, Julian Morris, later joining the Nuffield Orthopaedic Centre as the first motion laboratory director. Julian left academia in 1977 to become the Technical Director of Oxford Medical Systems, part of the Oxford Instruments Group and was replaced by Dr Mike Whittle who had spent the previous three years working with NASA in Houston, Texas supervising musculo-skeletal experiments on the SkyLab Space station. Mike used his unique experience as both a scientist and clinician to develop useful motion capture software to further embed the laboratory as an essential part of the hospital as it of course remains to this day.
So, Oxford’s first contribution to motion analysis has been as one of the early adopters of this emerging technology that was fully embedded within both an active research and busy clinical environment for nearly 40 years. The international contributions of those in Oxford have been legion including Julie Stebbin’s foot model to identify just one example of many.
In 1978, Julian negotiated a license agreement with John Paul, then the Head of the Strathclyde Bioengineering Unit, to start manufacturing a re-designed motion capture system. The first commercial products were supplied to study sheep gait in West Virginia and the second to Dr Sheldon Simon MD of the Boston Children’s Hospital, yet another portent to the future.
I arrived in Oxford in 1984 on a scholarship from an Australian teaching hospital to work with Julian so I could learn about British industry. At that time I was filled with lashings of self-importance having been the physicist on one of the first teams in the world to successfully undertake high energy cardiac ablation on patients, but very quickly learnt that Oxford was analogous to an intellectual vortex and that I was actually clinically stupid when in such an exciting and stimulating environment. The establishment of the Oxford Orthopaedic Engineering Centre within a hospital was truly inspirational to me as it gathered engineers, scientists and clinicians together to address many practical problems and to undertake useful research in such a plethora of subject areas. My first introduction to this world was to meet Derek Harris, the then director and former Lancaster bomber pilot, followed by getting to know and collaborate with many of the hugely talented staff on a number of interesting projects. I have since found myself content to ride on the shoulders of giants and I have to say to you that the view has been pretty spectacular.
So, Oxford’s second contribution has always and continues to be to attract amazing talent who settle in our fine city to pursue their careers to both apply and advance our subject.
Some of our colleagues do move on to pursue other opportunities including Ed Biden completing his DPhil at Hertford College before joining Dr David Sutherland at San Diego Children’s Hospital where he wrote clinical applications within their new gait laboratory and Mike Whittle taking up the Cline Chair of Rehabilitation Technology at the University of Tennessee at Chattanooga. Mike is the author of the seminal book “Gait Analysis: An Introduction”, now in its 5th edition titled as “Whittle’s Gait Analysis”. Long collaborations have been forged with our many of our international colleagues including those driving acceptance of routine clinical gait analysis and research including Herman Woltring, James R. Gage, David Sutherland, Murali Kadaba, Roy B. Davis and Jacquelin Perry to name but a few luminaries.
So, Oxford’s third contribution is to continue to stimulate an open, collegiate and intellectual environment that strongly encourages international collaboration between scientists, engineers and clinicians.
Soon after I arrived to work for Julian, the Oxford Instruments Group decided to focus on their core activities by building cryogenic magnets for MRI, having no further interest in biomechanics and deciding to sell or close the business. Julian gathered a small gathering of us to buy the assets and to build a new company. Apart from the good Dr. Morris, few of us had any spare cash to grasp this opportunity until Sir Martin Wood, the founder of Oxford Instruments, loaned each of us the funds to buy the company from him only on the understanding we would pay him back in 12 months, which of course each of us did. From our own history and in our own way over the last 32 years we have learnt from Sir Martin’s act of inherent philanthropy and have tried to stimulate a collegiate and collaborative culture where the lines between academia and industry are deliberately blurred that we have found has always been reciprocated in full.
So, the fourth contribution of Oxford to motion analysis has been to encourage academic and industrial collaboration in a nurturing environment where the get rich quick phenomena popular in some reality television offerings has no practical place or function.
I am reminded of the children’s game where blocks are placed one on another and then slowly removed until there is a collapse of the whole for the delight of all present. The part played by our wonderful Oxford has been significant and far reaching from so many different viewpoints including those that I have touched upon but I think we may be entering a challenging time following recent choices by a majority of the electorate. I believe we must all strive in our own ways to protect this most valuable edifice, a powerhouse of intellect and international collaboration because Oxford’s contribution to motion analysis was and is because it is Oxford.