The authors present the findings of a biomechanical research project carried out at the 7th World Championships in Athletics Seville 1999. This project was focused on the sprint events only. The objective of this project has been to analyze the performance in the 100m and 400m sprints, to produce reference values for training programming and obtain a methodology based on two dimensional video system ready for the kinematic analysis of competition. In the following the results of the men's and women's sprint finals are illustrated and interpreted.
The men's and women's 100, 200 and 400m sprint events at the Seville World Championships were analysed as part of the Biomechanical analysis project for the throwing and running events at the 1999 IAAF World Athletics Championships. This project was approved by the International Amateur Athletic Federation and financially supported by the Spanish Interministerial Commission of Science and Technology (CICYT) and, for running events, by the Higher Sports Council (CSO) of Spain. To carry out the filming process, we relied on the support of the Biomechanics research teams from the Physical Education National Institutes of Leon and Lleida, the Faculties of Physical Activity and Sports Sciences at the Universities of Granada and Valencia, and the European University of Madrid
This kind of analysis has been carried out at major competitions for more than a decade, as it provides coaches and athletes with very useful information as an aid to training programmes and competition preparation. The race analysis of the top athletes in the world in each specialty serves as a reference for assessing technique and rationalizing the results achieved. The results of the World Championships in Rome 1987 (Landry, 1987), Moravec and coll., (1988); of Athens 1997, Brüggemann and coll. (1997) and those of the Seoul Olympic Games (1988) published by Susanka and coll. (1989 a, b and c) and of Brüggemann and coll. (1990), have served as a reference for designing the experimental procedure for the different events.
Outstanding results were achieved in the World Athletics Championships Seville 1999 in the men's 100 and 400m sprints. Maurice Green's result was only 0.01s slower than his own world record, and Michael Johnson achieved a new world record with a time of 43.18s, 0.11s faster than the former record. The results will be disseminated world-wide and coaches will be in a better position to design training strategies in line with current world trends.
The objectives of this study were:
3. Material and methods
3.1 Subjects The sample consisted of: 24 men, finalists of the 100,200 and 400m sprint events; 24 women, finalists of the 100, 200 and 400m sprint events.
3.2.1 Filming instrumentation
100m sprint events:
6 SVHS video cameras, Panasonic MS1\MS4\MS5\625 AG-DP800HE.
4 digital high-speed video cameras, Kodak Motion Corder Analyzer SR 500c.
200m sprint events:
5 SVHS video cameras, Panasonic MS1\ MS4\MS5\625 AG-DP800HE.
4 digital high-speed video cameras, Kodak Motion Corder Analyzer SR 500C.
400m sprint events:
8 SVHS video cameras, Panasonic MS1\ MS4\MS5\625 AG-DP800HE.
4 digital high-speed video cameras, Kodak Motion Corder Analyzer SR 500c.
3.2.2 Instrumentation for the analogic recording of filming
For all sprint events:
2 SVHS video recorders: JVC HR-S7000EH.
2 5in/40ut Kramer Vertical Interval Switchers.
2 Time code generators.
2 Colour TV monitors.
Wiring for connecting cameras to the recording systems.
3.2.3 Instrumentation for the digital recording of filming
For all the filming:
4 Video walkman Hi-8 (Sony).
2 Notebooks (Pentium II 350 MHz).
3.2.4 Data analysis system
2 Panasonic AG-7350 video recorders.
1 computer with a Video Capture Board.
1 computer monitor.
1 Pentium III computer with the following components:
Miro DC30 Video Capture Board.
Adobe Premiere Video editing software.
3.2.5 Data processing system
Excel software with calculus routines developed by the Laboratory of Sports Biomechanics of CARICO.
Analogic video cameras, operating at 50 Hz, were placed perpendicular to the running direction for filming the athletes when passing through markers placed at the following distances: 100m event: every 10 metres; 200 and 400m events: every 50 metres.
Digital high-speed video cameras, operating at 100 Hz, filmed the athletes passing through the following distances: 100m event: From the start to 15m and from 50m to 65m.
200 and 400m events: From 100m to 115m for both events and from 150m to 165m for the 200m and from 350m to 365m for the 400m.
Figure 1 presents the location of the cameras for the 100m events; figures 2 and 3 present the location of cameras for the 200m and 400m events respectively. Prior to the races, the markers at each distance were filmed and, later on, the athletes were filmed passing them.
3.3.2 Recording of the pictures
Each camera was connected to a recording system in which the pictures of the athletes passing the markers were video taped. Odd number cameras were connected to recording system number 1 and even number cameras were connected to recording system number 2. The signals of the cameras filming the athlete were recorded by the switcher mechanism for each system. At the same time that the signal was video taped, a time code was inserted on the magnetic tape that later would be displayed for the time analysis. The time codes of both recording systems were synchronised in order to identify the corresponding moments in each event.
Digital cameras were connected to their processors for downloading data to the notebook in digital format: tif or bmp.
3.3.3 Data analysis and results output:
The footage of both systems was processed the same way in the laboratory:
The video tape pictures of both the action and the markers were captured and stored in a computer using the Video Capture Board. Avi files were created with video editing software to be analysed, using the resources of the programme. Sequences were digitised in order to register the time codes at the instant that each athlete passed the previously filmed markers along the running track. The anatomical reference point to digitise was the hip. The markers were displayed in the monitor and superimposed on the sequence of the athlete running.
The data was entered in a calculus routine, developed in the Laboratory of Sports Biomechanics.
Time data was processed to obtain the following information:
1. Interval times for 10 or 50m sections depending on the race.
2. Times at the end of each section throughout the race.
3. Comparison of the time intervals between athletes in 10 or 50m sections.
4. Differences in the winner's time.
5. Relative time of each section.
6. Evolution of the speed curve throughout the race.
7. Maximum mean speed and sections in which it is achieved.
8. Time intervaIs from 30 to 50m (100m race).
9. Time intervals from 80 to 100m (100m race).
10. Time intervals every 100 metres (200m race).
11. Time intervals every 100 and 200 metres (400m race).
12. Reaction times from the official timing.
In the following the results are presented in the order:
1. 100 m final men (pp. 28-35)
2. 100 m final women (pp. 36-43)
3. 200 m final men (pp. 44-47)
4. 200 m final women (pp. 48-51)
5. 400 m final men (pp. 52-55)
6. 400 m final women (pp. 56-59)
Results of the men's 100m final
Sprint coaches are accustomed to handling data on split times as shown in Table 1. This table presents individual data for the different athletes which allows the results of the race to be interpreted and comparisons to be made between the athletes. The fastest time was clocked by the present world record holder Maurice Greene (USA) with 9.80s. Surin who came in second, clocked some split times which were lower than Greene's up to the 50m point from when Greene obtained an advantage of 0.04s (Tables 1 and 2). Montgomery, who was third in Athens with a time of 9.94s, only achieved a time of 10.04s in Seville and came sixth. By observing the data presented in Table 1 and Figure 1, he can be seen to obtain a poorer time between 10 and 30 metres and although he recovered well at the end he was not able to win a medal.
These conclusions are reflected in Figure 1. Greene lost the world record at the start, and clocked the worst time of all the participants in the 10-20m stretch; but then he obtained a progressively better time than all his opponents. The bronze medallist, Chambers had a good start, but lost ground to the first two athletes and began to fall away from them beyond the 60 metres mark, after which his split times were worse. Table 2 shows the differences in each split time with regard to the winner, with negative values representing the best times and positive values those which are slower. Table 3 shows the accumulated times of each athlete as the race develops, showing the place each one held throughout the race. For example, Surin was first up to the 70 metre mark, at which point he was caught by Greene.
The accumulated times for the 30 to 50m stretches give an idea of how each athlete accelerated, and from 50 to 80m how they decelerated. Table 4 shows how the athletes who won the races were the ones who obtained the best times over these 20 metres. This could be interpreted as meaning that those athletes who manage to obtain a good time over this stretch, seem to be the ones most likely to win. Table 5 shows that the first two at the finish lost less time than the rest of the athletes, that is to say, they were capable of maintaining their speed up to the end, and Thompson, although he recorded a good time, was not able to overcome the disadvantages he suffered in the first 10 metres and in the 30 to 50m stretch.
Table 6 and Figure 2 show the speeds achieved. The highest average speed recorded was that clocked by Greene (11.90 m/s), which he achieved between the 50 and 60m marks. No athletes ran slower than 11.36 m/s in their best stretches, which means running the fastest 10m stretch in less than 0.88s. Average running speeds between 9.77 and 10.20 m/s were reached. The evolution of average speed in each section by each athlete is shown in Figure 2. Table 7 shows the maximum speed of each athlete and the stretch where it was achieved. Table 8 details the reaction times provided by the IAAF, where the best time was clocked by the silver medallist who later reached his average speed ten metres before the others (Table 7).