The Paralympic games are bigger than ever, with 4280 athletes competing across 166 teams, and much new found media attention. A lot of this attention can be attributed to the ‘blade runner’ from South Africa, Oscar Pistorius, who is very much the poster boy for the Paralympics.
The story of Pistorius is an undeniably inspiring one. He is a double below-the-knee amputee, with both lower legs being taken at the age of 11 months old. Rather than letting his disability limit him, Oscar had his limbs replaced with ‘blades’, which not only allow him to walk, but also run-fast! His notoriety was secured when this summer Oscar Pistorius became the first disabled athlete to run in the Olympic Games.
However, controversy has accompanied the South African ‘blade runner’ with his increasing fame, with people across the globe debating whether athletes using running blades should be allowed to compete in the Olympics.
Further controversy raised its head several weeks ago, when Oscar Pistorius suffered a shock defeat in the 200m T43/44 final at the hands of Alan Fonteles Oliveira from Brazil. Pistorius was more than a little disgruntled about the result, claiming that the length his rival’s blades gave him an unfair advantage. Since this, other leading paralympians have entered the debate regarding running blades. Jerome Singleton, a single leg amputee from the United States, has voiced concerns that athletes using two running blades could have an advantage because of the length alterations they can make to the blades to suit the race.
This article looks at the composition and manufacture of these running blades to hopefully shed some light onto how they affect an athlete’s performance. Below is a video from running blade manufacturer Ottobock, displaying how a running blade can be used for athletics as well as in everyday life.
Running with the new above-knee sports prosthesis from Ottobock.
How Are The Blades Made?
The running blades used by amputee athletes are an advanced type of prosthesis, or prosthetic limb, which are used to replace a missing body part.
In general, there are three main parts to a running blade:
- The blade itself
- A socket to attach the blade to the body
- An artificial knee joint (if required)
Invented in the 1970’s, the blades store kinetic energy in a similar fashion to a spring which allows the athlete to run and jump. The blades themselves are made from lightweight carbon fibre. Carbon fibre is a resilient material that is stiffer than steel, and around five times stronger. Stands of carbon fibre are twisted tightly together to form a continuous layer, and these layers are then laid over the top of each other to form the blade. Over 80 layers of carbon fibre are required to make one running blade, and these need to be laid by hand. The blades are the moulded by pressure and heat to fuse the layers together and then this can be shaped into the final blade. These blades can be customised to the athlete’s particular requirements.
The motion of running is replicated as closely as possible by the blade – therefore the blades do not have a replica heel, as this is not used in natural running. To assist with gripping the track, blades can be fitted out with running spike, just like standard running shoes. These can be troublesome to attach to the smooth carbon fibre blade and are often attached by hand. The spikes used by Oscar Pistorius are provided by Nike, in the form of a special ‘spike pad’, which is affixed to the bottom of the blade. A pair of running blades can cost around $5000 per pair.
Sgt. Jerrod Fields, a U.S. Army World Class Athlete Program Paralympic sprinter hopeful, works out at the U.S. Olympic Training Center in Chula Vista, Calif. A below-the-knee amputee, Fields won a gold medal in the 100 meters with a time of 12.15 seconds at the Endeavor Games in Edmond, Okla., on June 13, 2009. Image Credit: Tim Hipps, FMWRC Public Affairs
Even Better Than the Real Thing?
One of the main debates involving prosthetic running blades is whether they give the athlete an unfair advantage in a race.
Compared to a natural limb, this will not be the case. The idea of the blades is to restore as much functionality to the runner as possible, rather than to enhance abilities. There is no muscle power in the limb itself, meaning that an athlete only has the power generated by their hip flexor muscles and hamstrings. Furthermore, whilst a real limb returns 250% of the energy stored, a running blade will return a mere 90%.
A more important argument is whether the length of blade can make a substantial difference to the performance of an athlete in a Paralympic event. Many blade manufacturers argue that no two pairs of blades will be the same, as no two athletes that use them are the same. The different natural heights of athletes are used to determine the optimum and most natural length of running blade for that particular athlete. However the IPC has agreed that more research needs to be undertaken to find out that exact effects of different types of running blades in athletics.
This particular debate is destined to run and run, long after the Paralympics have ended.
Sources and Further Reading