Sometimes an individual can change the entire face of sports. One such man was sprinter Usain Bolt. For ages the archetypal sprinter was short and broad-shouldered, until Bolt at 6 ft 5 in (1.96 m) hit the scene in 2009, breaking every record. ‘His height turned out to be an advantage. Running much faster that Usain Bolt is hardly possible for a human being’, says Bert Otten, professor of Neuromechanics and Prosthetics at the University of Groningen. Nor will humans be able to run faster in the future. ‘We are now nearing the built-in limits of the human body.’

The curve portraying 100-metre sprint records is levelling off. The time Bolt managed (9.58 seconds) wasn’t actually expected to occur before 2068, according to the extrapolated curve.

Slow starter

It’s striking that Bolt is a slower starter than his main rivals. ‘It takes a while for him to really get up to speed. Looking at him, you understand what’s going on immediately,’ Otten says. ‘The average ratio between lower leg and upper leg is 103 percent. Usain Bolt’s is 112 percent. His lower legs are much longer than you would expect, given the length of his upper legs − a full six centimetres longer than normal. His calf muscle is relatively small and is set very high, like a horse’s.’

Low step rate

With every step the foot briefly comes to a standstill. From there the foot must move forward as quickly as possible. In Bolt’s case this is at a speed of nearly seventy kilometres per hour. ‘It’s helpful that there is little mass in the foot region, and for the step rate to be low, as is the case with Bolt. It gives him more time to use his strength.’

Height as advantage

Until recently, tall people were discouraged from becoming world-class sprinters. Bolt’s feats, however, have shown that height can be an advantage. If the proportions are right, that is. Otten: ‘I’m pretty certain that people with short lower legs will always lose as sprinters. They can train as much as they like, but that will only increase their chances slightly. They’ll never manage to break Bolt’s record.’

Super athlete

In running, there are a number of limiting factors: gravity, muscle power, muscle speed, build and surface contact. With regard to build, type of muscles and training programme, Bolt is near to doing the utmost possible, Otten thinks. ‘His determination makes him a super athlete – a dedicated monster. And he’s also in his sprinting prime. I doubt he will ever run 9.40, but I do think he will manage to end up just above 9.50.’

Maximum speed

We’re now nearing the built-in limits of the human body, although the record will undoubtedly continue to creep up’, Otten says. ‘We’re also able to measure time better and better. We’ll manage to keep things exciting one way or another. Even if records in the future will be about hundredths of seconds, there will always be something to win, although the new records will be only by incremental increases.’

Theoretically, changes made to the running surface could also lead to new record times. ‘This could be done by tuning the stiffness and cushioning quality of the running surface to the individual ratio between height and weight. And otherwise we could teach athletes to run with leaf springs under their feet’, Otten speculates. ‘But that wouldn’t be good. Its sheer simplicity is what makes the sport so elegant. It’s one of the few sports where you can really compare “unadorned” athletes.’

Curriculum Vitae

Bert Otten (The Hague, 1954) studied biology at Leiden University and was awarded his PhD in 1982. The same year he joined VU University Amsterdam to conduct research on the functional morphology of the human back. Otten has worked for the University of Groningen since 1984, where he was with the Medical Physiology department until 2001. He then became associate professor at the Institute of Human Movement Sciences of the University of Groningen. He has been Professor by Special Appointment in Neuromechanics and Prosthetics since 2005.