2015年9月14日星期一

Biomechanical Analysis of Usain Bolts 9.58 sec World Record


At the IAAF World Championships in Berlin, the German IAAF Member Federation, DLV, in cooperation with the IAAF is carrying out a major Biomechanics Project.

The project presented the reaction times and splits for all the finalists from the 100 metersemifinals and the final at the 2009 IAAF World Championships in Berlin.
We thought we would present them here and try to predict just how fast Usain Bolt can run.
This table gives us some real insight into Bolt's race. Lets take a look at some crucial points in the race. You can click on the table to see the details.

Of the 8 finalists Bolt has the 3rd slowest reaction time to the gun, at 0.146 seconds. Both Asafa Powell with 0.134 secs and Tyson Gay with 0.144 secs react faster.
By the 20 meter mark though Bolt has caught up all this time and gone ahead of Powell by 0.03 secs.
From the 20 meter mark on, Bolt is away and getting further away over each 20 meter interval. Although we can also see that Tyson Gay is able to hang pretty close between 20 and 80 meters.
Bolt reaches his top speed of 12.27 m/s or 27.45 miles per hour at the 65 meter mark. This can be seen in the second graph presented by the IAAF Biomechanics Research paper.
From 80 to 100 meters Bolt actually begins to slow down. We can see that his time for the last 20 meters is 0.05 seconds slower than his fastest 20 meter split of 1.61 seconds. We also know that he reached his maximum speed at 65 meters and everything after that was a little slower.
One last thing to note is that in this race there is a tail wind of 0.9 m/s. This is legal but it does give the athletes a slight advantage as it pushes them along.
To determine how fast we think he can run, lets look back at the Beijing Olympics and remember how analysis of that race suggested that if Bolt had maintained his speed through the last 20 meters and did not begin celebrations, he could possibly have run the 100 meters in 9.55 seconds.

His current world mark is pretty close to that already, so where can he improve to make up the time. So here are some key factors that are critical to determine how much faster he can go.
Firstly look at the table again and at Bolt's reaction time (RT) for his semi-final. In this race he gets out in 0.135 seconds as against the 0.146 seconds in the final. We also see that he completes the first 20 meters in the same time in both the semis and final, while he definitely seemed to be cruising in the semi-final. It has also been suggested that Bolt actually covered the first 20 meters in Beijing faster than he did in Berlin. This is up for debate though, as the video analysis was done using broadcast footage where the camera setup was not optimal. In any case, Bolt can definitely get out of the blocks faster and should be able to cover that first 20 meters faster than he did in Berlin.
The prediction from the Beijing Olympics was based on the suggestion that Bolt could maintain his speed at 80 meters through to the end of the race. In Berlin however, he is not able to do this and slows down a little over the last 20 meters. We also notice that all the athletes in the final ran slower over the last 20 meters, than in the split between 60-80 meters (which was the fastest for all of them). Therefore it may be impossible for a 100 meter athlete to maintain their speed over the last 20 meters and the Beijing prediction may have been optimistic in this regard.
In the last 10 meters in Berlin, Bolt takes a look out of the corner of his eye to check on Gay. We don't believe this could have caused too much of a slow down. In fact if we look at his average velocity at the 90m and the 100m mark from the research, we can see that he does not slow down between those 2 points. But lets assume he could have been 1 or 2 hundredths of a second faster if he had not checked.
The 0.9 m/s tail wind in the final in Berlin will definitely have helped Bolt. A tail wind of up to 2.0 m/s is considered legal for a record to stand. Therefore there is an advantage to be gained with the right conditions.
Finally we have some sort of answer. We think Bolt can definitely run faster. If he improves his reaction time and runs hard through the finish in the right conditions, we have no doubt a new world record will be set.
I am sure we would all love to see an athlete challenge the 9.50 second barrier and Bolt may have it in him to do just that. We look forward to watching it all.
Equipment accessories: airplane, ship, bicycle, motorcycle, auto, medical, chemical, wheel, sports, anchor, weapon, etc.
Sampling inspection for Chemical composition and Mechanical properties like Tensile strength etc

Dimension measurements like Thread size, Height of head, Depth of socket etc

Features

1.Low Density and High Specification Strength
2.Excellent Corrosion Resistance
3.Good resistance to effect of heat
4.Excellent Bearing to cryogenic property
5.Nonmagnetic and Non-toxic
6.Good thermal properties
7.Low Modulus of Elasticity
Applications

Equipment accessories: airplane, ship, bicycle, motorcycle, auto, medical, chemical, wheel, sports, anchor, weapon, etc.
Aircraft Bolts AN, MS, NAS, HEX Head

没有评论:

发表评论