Department of Engineering / News / Interview with Matthew Juniper, Professor of Thermofluid Dynamics

Department of Engineering

Interview with Matthew Juniper, Professor of Thermofluid Dynamics

Interview with Matthew Juniper, Professor of Thermofluid Dynamics

Matthew Juniper competing in the long jump in Atlanta, 1996

In this interview with the Cambridge Blue Bird, Matthew Juniper, Professor of Thermofluid Dynamics in the Department of Engineering, speaks about his time in the Paralympics and how this influences his work.

I think we may soon see amputee athletes regularly out-performing their able-bodied counterparts in some events.

Matthew Juniper

Professor Matthew Juniper read Natural Sciences and Engineering as an undergraduate at St John’s College from 1992 to 1997. In 1994 his leg was amputated after being badly broken during a rugby match. He started sprinting competitively in 1995 and competed in the Atlanta Paralympics in 1996, coming 4th in the 200m. He won silver in the 4x400m relay at the Birmingham World Championships in 1998. He is now Professor of Thermofluid Dynamics in the Department of Engineering and a fellow of Trinity College.

Thank you for talking to us! For starters, tell us a bit about your general sporting background.

I was a fast runner at school, mainly 400m and 800m, but decided to play rugby at university because it is more fun. Being fast and good at tackling, but not particularly skilful with a ball, I played either wing or full-back. I broke my leg at the end of a gritty wet game against Caius in a bad collision that was entirely my fault. Psychologically, it is easier to bounce back from a self-inflicted injury than one caused by another person. Since then I have continued to run and ski. I tried to play rugby again but the referee, quite rightly, wouldn’t let me onto the pitch in case I injured another player. In compensation I was called upon to kick conversions on informal tour matches – it’s amazing how hard you can kick a ball when you know it won’t hurt!

At what point did you take the decision to start to participate in sports again?

They decided to amputate my leg after six weeks of increasingly unsuccessful operations and, by that stage, it came as a relief. While in bed I had had plenty of time to consider a future with a limp leg – in a weak moment I had even considered taking up golf – but the amputation opened up more interesting possibilities. Two years previously, in 1992, I had seen snippets of the Barcelona Paralympics and remembered the single amputee Denis Oehler complaining that the double amputee Tony Volpentest had won gold only by making his legs 3 inches longer than they should have been. (Pistorius and Oliviera had exactly the same argument after Pistorius’ defeat in the 200m at London 2012.) The fact that an amputee could run 100m in under 12s intrigued me in 1992. It became more relevant to me in 1994 and was a huge source of comfort as they wheeled me down to theatre. So I think seeing the 1992 Paralympics was instrumental in my decision to take up running with an artificial leg. It was an honour to be comprehensively beaten by both Oehler and Volpentest in the 1996 Paralympics (Volpentest went on to win the T43-44 100m final in a World Record time of 11.36s).

What exactly made you settle on sprinting?

After an amputation there is a period of rehabilitation, in which physiotherapists, prosthetists, and occupational therapists prepare you for your new lifestyle. Some seem to encourage you to play the victim and live off allowances. I was lucky enough to have a prosthetist who knocked together a skiing leg after three months and a running leg after six. There is no purer rehabilitation than carving an edge down a piste or running faster than your two-legged friends. Nevertheless, the therapists are not completely wrong. A new stump is malleable like plasticene and, when I started running with the British squad in mid-1995, I could not run further than a few hundred metres before my leg wobbled loose. This meant that 100m, 200m, and long jump were my limits. There are other sports for amputees, such as volleyball and swimming, but nothing could compete with the exhilaration of sprinting into a wall of wind on an angry blade of carbon fibre.

How did it feel at the time, to compete in the Atlanta Games in 1996?

Perhaps I can best convey the feeling by describing the process leading up to a race. You are told to assemble with the other athletes at the warm-up track several hours before the race, which is when the psychological battle begins – I heard one competitor, with Oscars-worthy concern, ask another why he was looking so sluggish. After an hour or so of warm-up, the eight in each race are bussed together into a small dimly-lit room below the stadium to stare at each other until the race is called. Then the marshals lead you through a tunnel towards a small rectangle of light that suddenly expands into a blinding arena containing 80,000 cheering people. On the big screen you see your other self strip down to shorts and vest and hand all his belongings to a marshal. You look down the lane, to a finish line so close you could touch, crouch on the blocks, and find yourself three steps into the race before you realise the gun has gone off. Everybody has the same feeling about a big race: at the start, you would rather be anywhere else in the world. At the end, your only desire is to experience it again.

And how does having competed in the Paralympics make you feel now?

I continue to be fascinated by the Paralympics and the fact that, for events such as the 400m and long jump, well-designed artificial legs seem to perform better than real legs. The public clearly shares this fascination, particularly for disabled athletes such as Oscar Pistorius, who progressed to the Olympic 400m semi-final, and Markus Rehm, whose recent long jump would have beaten Greg Rutherford to gold in the London Olympics (he jumped 8.40m at the 2015 World Championships). In one important way, I think that the Paralympics is a more profound event than the Olympics. In the big scheme of things, it is not important that an athlete can run 100m in 10s – most people will never bother trying. However, to the many thousands that are born disabled, or have disability thrust upon them, it is extremely important that a one-legged athlete can run 100m in 11s. Most will never try but all will know it can be done, and that is a chink of light in a dark place. Of course, there are some surreal moments: just before Pistorius’ bail hearing, a journalist from South Africa telephoned to ask me whether all amputees resent able-bodied people so much that they would shoot them at the slightest provocation. I told him that I didn’t know, but that he should come to Cambridge and we would find out.

Do you feel that the status of Paralympians and the coverage they receive has improved since you competed?

In terms of coverage, London 2012 took the Paralympics to a new level. Some of the categories of disability are quite nuanced and these were explained thoughtfully by well-informed presenters. I think the public responded with genuine interest, and not just morbid curiosity. In terms of status, a handful of Paralympic athletes have become as well known as their Olympic counterparts, which is tremendous. I think, however, that the most important change signalled by London 2012 was epitomised in The Last Leg, a chat show hosted by two amputees, which contained much of the dark humour that is rife amongst people who are missing various limbs. This would have been unthinkable a generation ago, when we were told not to stare at people in wheelchairs and thought it better to pretend they did not exist. Today we know it is OK to ask about disability and even to laugh with disabled people when they make jokes about themselves, so I think that the status of all disabled people, not just Paralympians, has improved.

Do you feel more should/could be done for Paralympians?

Not really. All those I know strongly resist anything being done for them. They want to earn it for themselves.

You happen to also be a professor in Engineering at the university – do you take much interest in how the prosthetics are designed and the engineering that goes into them?

Absolutely. I think we may soon see amputee athletes regularly out-performing their able-bodied counterparts in some events. The key factors are that, firstly, an artificial leg can be tuned to a specific natural frequency and, secondly, it can flex more, allowing more contact time with the ground.

Regarding the first factor, if you stand on one leg and bounce on your toes, you will find that the natural frequency of your leg is around 3 Hertz. At a running cadence of 3 Hz, your tendons absorb energy as you land and release it just as you push off. This allows maximum energy recovery each step and is ideal for long distance running. At this cadence an elite athlete can run 100 m every 16 seconds for 10,000 m. The cadence required to run 100 m in 10 seconds, however, is around 4.5 Hz. At this cadence, you have pushed off before your tendons can return all the energy absorbed during the landing, which wastes energy. No athlete can maintain this pace for more than around 400m. An artificial leg can be tuned to 4.5 Hz, however, allowing maximum energy recovery each step at sprinting speed. This seems to give two-leg amputees an advantage over able-bodied athletes at 400m, which is an endurance race at near sprint cadence.

Regarding the second factor, an artificial leg can be designed to flex more than a real leg resulting in more contact time with the ground. This allows the amputee athlete to push against the ground for longer each step than an able-bodied athlete, albeit with a reduced force because they do not have a calf muscle. The change in the athlete’s momentum caused by each step is the contact force multiplied by the contact time, so the longer time makes up for, and possibly outweighs, the reduced force.

This debate, about whether an artificial leg is better than a real leg, is heated and sometimes acrimonious. Having given my tuppence worth, I’ll run for the hills and see what happens in Rio this year.

The text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright ©University of Cambridge and licensors/contributors as identified.  All rights reserved. We make our image and video content available in a number of ways that permit your use and sharing of our content under their respective Terms.