The 2010 edition of the Tour de France is approaching its conclusion in Paris. The race for the yellow jersey, or winner of the Tour, has been an exciting one. Alberto Contador and Andy Schleck have been the stand out riders in the mountain stages. The two are seperated by a small margin of only 8 second, which Contador gained because of a mechanical failure at a critical moment for Schleck.
Stage 18 of the race should put the focus back onto the sprinters, at least those that made it through the mountain stages. The stage sprint winner will rely on skilled lead out riding from their team mates and powerful sprinting to gain the victory. The 2010 Tour has seen dangerous and sometimes illegal moves in the sprints. Mark Renshaw, of team HTC Columbia, was disqualified for head butting another sprinter (not once but three times) as he lead out and created a sprinting lane for his team mate Mark Cavendish.
The sprints seem so chaotic that we wonder how anyone can get through without some illegal moves. The video below describes the cycling rules for sprinting and shows some examples of what is allowed and what can and should lead to disqualification.
Two more sprints will be contested in the 2010 tour and we can look out for the way in which the sprinters and their lead out men ride their lanes and deviate from them to cut off opposing team riders.
Mark Cavendish is once again favored. With his speed and power he does not need his team mates to head butt other riders to get another win and without his lead out rider Renshaw, he will get his chance to show us.
Another week and another call for the use of video replay in sports. This time from the football (soccer) World Cup qualifier between France and the Republic of Ireland.
Frances' William Gallas scores from an assist by team mate Thierry Henry. Replays and video evidence clearly show that Henry used his hand, intentionally, to control the ball before crossing it.
Watch the video below. Although I believe that Irish football commentary is often biased for their team, the commentary in this video is not biased. It is obvious that this goal should have been disallowed by the referee or the linesmen.
Henry admitted after the game that he had used his hand. I am not sure that any player with the desire to win this do or die World Cup qualification game would not have risked the same. I am sure he even expected the goal to be disallowed. Henry conned the referee and linesmen. Similar cases, particularly of players diving to win penalties, are prevalent in football at all levels and throughout the world. Players should never in my opinion deliberately try to con the referee. However I have no intention of passing judgement on Henry's character or that of any other professional athlete. This website is about video analysis, so once again we will harp back to a previous discussion on the use of technology and particularly video replay in sports.
In this particular instance we had some clear evidence of the hand ball from the TV footage. But again we need to point out that the evidence is not always that clear. See our previous post on video technology for refereeing. There have been numerous calls in soccer when the decision could have gone either way because of lack of clear video footage.
Watch this video of Wayne Rooney falling to win a penalty against Arsenal earlier this year. This decision is less obvious, was Rooney already falling or did the Arsenal goalkeeper touch his foot and bring him down? Was the ball close enough to be retrieved before going over the goal line? Even on watching the video it is a difficult decision to make.
The video technology in this case has let us down. A side on view of this same incident would have enabled us to better assess the position of the ball and the point at which Rooney begins to fall. We would also have been able to tell when Almunia, the Arsenal goalkeeper makes contact. So here is a decision that even with video replay remains controversial.
I believe that some amount of controversy actually brings excitement and emotion to the game. As a fan of a losing team, what better way to make yourself feel better than to suggest that the team would have won if the referee/player/coach/linesman hadn't cheated. In fact had Henry's goal for France been disallowed, Ireland would not have automatically won as many of the Irish believe (the score was 1-1 on aggregate before the goal went in), and may even have lost in the end anyway. Now just think of the great grudge match when France and Ireland meet again, even in sports other than soccer.
The problem is the blaming. With a referee in charge there are bound to be honest mistakes on occasion. Sometimes there may even be some blatant bias. The players too can make honest mistakes. A player falling over in the penalty box is not always trying to win a penalty, he may be trying to avoid injury.
Video replay technology can give increased accuracy to the decision. A referee is not always in the perfect position to make the most accurate call. Video from different angles can give the official added perspectives to help make his decision more accurate.
Video technology can remove all of this bias and simplify things. However it currently is not 100% accurate and controversial decisions will remain when the perfect camera angle is not available.
As technology progresses and even now with a good camera placement, such as those used in cricket and with the Hawk-Eye system for tennis, even more accurate decisions can be made.
It's time to bring in the video replay for all sports that rely on a referee or umpire to make a decision.
The Tour de France is the ultimate in road cycling competition. Covering 3500 kilometers (2187 Miles) over 22 days, the event tests the cyclists mental and physical strength. To complete in this grueling endurance test, the athletes need to be in peak fitness, but they also need to ensure their technique is as efficient as possible. Energy can be preserved, injuries prevented and more power created with good technique.
The best way to evaluate your cycling form is with a few appropriately positioned video cameras. Although you may encounter flats, up hills and down hills on your bike ride, the general position for cycling is the same and therefore you can benefit greatly by improving the efficiency of your cycling power stroke. Although there may be various inclines and flat sections, your position during the ride is generally constant, and therefore you can benefit greatly by improving the efficiency of the cycling power stroke. The power stroke is the cycling pedal stroke including the push down and pull up of the pedal.
Assume you are sitting on the saddle of your bike with your upper body still (as it should be). The power required to turn the pedals over comes from the muscles in your hips, thighs and calves. This power is transmitted to the pedals, and from there drives the cogs and so on, turning the rear wheel.
Now for some basic physics. In order to push down on the pedal or pull the pedal up with the greatest force and the most efficiency, you will want your muscles to generate a force that pushes or pulls directly down or up on the pedal (depending on whether you are in the down stroke or up stroke of the pedal motion). Your hips, knees, and feet all need to be aligned correctly to produce a purely vertical force on the pedal.
In the image above we have the side view of a cyclist. The cyclist cannot use his thigh muscles to push directly down on the pedal but we can see that his knee is directly above the middle of the pedal which will allow him to push down efficiently as he straightens his knee. The force (red line) from his thigh muscles will be transmitted along with the force from the calves to the pedal. If his knee was in front of the pedal he would be wasting energy pushing backward, and if his knee was behind the pedal he would not be able to produce as much downward force because his knee would straighten too early.
A camera looking from the front would give us another important perspective. With this angle we will be able to see whether the hips, knees and feet all line up with the center of the pedal. Once again we want all the joints to align with the center of the pedal, so that all the force is generated directly through the pedal. If the cyclist's knees pointed outward rather than forward, he would be losing efficiency by generating a force that is not directly in line with the pedal. If he did this, he may also suffer from injuries as he attempts to maintain the same speed. He will need to recruit different muscles or strain ligaments and tendons to make up for his lack of efficiency
Video analysis of your cycling technique is easy to do with a couple cameras and a stationary bike. Below are 2 great examples. A side on view allows the cyclist to evaluate his position on the saddle as well as his knee and foot position.
A front on view allows the cyclist to check the forward alignment of his hips, knees and feet.
This cyclist looks to have good biomechanics and an efficient pedal stroke. For a more detailed analysis you can also use video analysis software to calculate the angles and accurately measure the positions.
Lance Armstrong will be in action again this year at the Tour De France and we look forward to seeing what he can do. Lance has spent many hours in testing wind tunnels measuring his bike performance, but we are sure he also uses this data to fine tune his biomechanics for maximum efficiency. So get out your video cameras and film yourself in action.
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