Tuesday, 3 May 2016

References

S,Bornhoft (2008). RYA Intermediate Windsurfing . Southampton : RYA.8-11.
G, Cribb. (2005 ). Pumping . Early Planning . 1 (1), 83-84.

S,Bornhoft. (2013). Olympic Technique . Available: http://www.windwise.net/component/content/article/9-uncategorised/227-olympic-technique. Last accessed 22nd April 201


J, Rohde . (1996). Essential Tips . Available: http://www.windsurfing.org/train05.htm. Last accessed 22nd April 2016.

Numerical Model

For my numerical model I looked into the pumping technique in windsurfing that is need to increase the speed of the athlete around the race course and accelerate, making it a vital skill in the racing discipline. I have analysed two athletes, one of high elite standard and one of lower elite standard. This allowed me to identify the differences between the athletes and where the strengths and areas to improve are.



From the data collected it can be identified that the athletes are very similar in the angles that they produce. However the angular velocity and angular acceleration of the elite model is 8.33 degrees per second/ 8.33 degrees per second, per second faster than athlete B (lower elite) this higher angular velocity/acceleration of the elite model will allow the athlete to create a higher power through the sail, therefore allowing their boar dot accelerate faster and at a higher rate. This will allow them to have an advantage over athlete B as they are getting a smaller power transfer through the sail, as the longer the movements the more power is lost and absorbed into the body and not channelled into the sail itself that allow the propulsion of the board in a forwards motion. 

Furthermore there is a 24 degree difference between the down phase of both athletes. Athlete A (higher elite) lowers to an angle of 135 degrees and athlete B lowers further to 111 degrees. This decrease of an angle in athlete B will allow them to create the extra power they require through their decreased angular velocity and acceleration. As athlete A has an increased angular velocity and acceleration it allows them to not get as low in points as the acceleration and velocity make up for the lost power that could have been created through the downwards phase by decreasing their angle further by getting lower. The lower the athlete gets will also increase the possible power output as they are increasing the movement angle and if the increase their angular velocity/acceleration it can maximise the gains that could be made. The main in the downwards phase of the pump is to get as low as possible and have a high velocity and acceleration as this will maximise the power that can be increased through this movement. From the measurements it shows that athlete B has a good angle when they are in the down phase (145 degrees) However due to their lower angular velocity and acceleration this counteracts the difference in angle between athlete A and B as A’s higher velocity and acceleration greater a higher power output through the sail. 

Athlete A however rises much closer to the rig creating an angle of 168 degrees, this allows the power transfer to the maximised through the mast foot and into the board as all their weight and the power being created by the body is being channelled through the centre of the board allowing the acceleration to be straight. Athlete B however only rises to create an angle if 146 degrees, this will reduce the amount of power that an be channelled through the mast foot and into the board as not allow their weight is placed over the centreline. This could also cause the board to drift sideways (especially in the lighter winds) as there will be a larger pressure build up against the dagger board that could cause the individual to ‘spin out’ due to the increase of pressure. 









Technical Components (3)

When the athlete isn’t pumping around the race course, they will be in the harness and constantly trying to keep the speed up. This is done by trying to keep the rig upright and still, this allows the power to be kept within the sail and propelling the board forward. People have different stances and movements that aim to keep the rig upright, sheeted in (Closed at the back) and power up allowing them to keep up to speed. “whilst keeping the rig as upright as possible” (S,Bornhoft, 2013) This article shows how important keeping the rig upright is as they have put it in the top 5 musts when linked to upwind sailing this makes it a massive areas for all athlete in the windsurfing field. This rig positioning is heavily controlled by hip positioning and weight distribution compared to the rig, fin and dagger board. “it's your hips that should control both the trim and direction of the board…swing them towards the tail to lift the nose and head up.” (J,Rodhe, 1996) The positioning of the athletes hips can effect the angle of the rig and the trim of the board, making it vital that they try and keep this correct during the time they spend in the harness throughout the race, as the wrong hip angles can effect their over all speed and upwind angles. 


Body positing can effect the pressure that is applied against the dagger board, creating the lift needed to yea  the board upwind and keep it tracking in a straight line. The more weight put in the harness allows less weight to be places over the board. This is beneficial as it will allow the board to stay at a higher speed. Furthermore bringing the weight outboard and committed it allows the board to remain mainly flat and adds the increased chance that the athlete can use the outboard in order to pull up the windward rail, and engage the leeward rail allowing the board to track further towards the wind. 
















From the pictures it can be seen that the first athlete (elite model) has a much better rig positing as it is upright and sheeted in. This will allow the athlete to maintain the speed and possibly gain, this speed gain will be a rest of the wind being harnessed and maintained within the sail. Because it is sheeted in and upright it is open to a larger percentage of wind, when a sail is sheeted out and lent over (athlete 2) this causes the wind to flow in and flow straight out of sail, therefore less wind is presented to the sail, causing the board to lose speed (as shown in the graph below). 



















From the photos and data I can identify that the athlete needs to improve both their hip positioning and weight distribution. Currently their hip positing isn't as significant twist as needed (around 45°). This less angled hip twist doesn't allow the sail to be sheeted in fully as the back arm is fully extended at the equal level to the front arm, causing there to be an decrease in the sheeting angle. This decrease in the sheeting angle will allow the wind to escape the sail easily, this escaping wind will cause the sail to lose power quickly as there isn't an enclosed area that will allow the wind to push the athlete forwards. Therefore this hip twist will cause the athlete to lose speed quickly, as illustrated within the graph this athlete lost 0.5 knots over a 5 minute period, this is an average of 0.1 knots per minute, this could be a huge loss across the race course since the upwind legs tend to be around 1KM long, this takes around 10-15 minutes wind dependant so by losing an average of 0.1knots due to their hip positioning effecting their sheeting angle. The speed loss will cause the athlete to lose positions around the race course, leaving them at a huge disadvantage. 

Weight distribution is also an area that would need urgent work as their current weight distribution is causing all of their body weight to be on and move the centre/ windward rail of the board. This weight being on top of the centre board, this is reducing the force against the dagger, as there is less force pushing against the dagger board this will reduce the pointing angle of the board as there is less resistance against the dagger. Furthermore the weight being over the centre line is reducing the board percentage in the water increasing the resistance which in turn reduces the speed overall. Similar to their hip positioning this could cause the individual to lose positions during the race and cause them to be in bad positioning, for example if another athlete has a better wight distribution the this will allow them to sail faster, if an individual sails over to top it will effect the wind causing the individual to have less and the lose even more speed. 

If the weight distribution and hip positing are correct this will give the athlete the best speed advantage over the other competitors. This speed advantage can also he advantageous when it comes to work rate because this will allow even more of a speed advantage as their starting speed is higher the pumping will accelerate this. This will also allow the athletes to be the decision maker in different situations as they will be slightly faster allowing them to force the other competitors into making different movements (e.g. tacking to the other side) as they can accelerate away from them. Therefore giving them the best advantage and chance around the race course.






Technical Components (2)

Grip positioning on the boom can also effect the pumping movement. An elite athlete will have their arms around shoulder width apart, this allows the power to be transferred from the body into the rig, this power transfer will have a positive effect on the pumping movement as it will make the action efficient and worth while completing. Research shows that ensuring hand positing is correct can help the positioning of the rig  and this rig positioning wi help create owed and flow throughout the rig. A forwards,upright rig is the most effect at ensuring that the pumping is efficient and creates a strong flow, in articles it is suggested that “Move your front hand right back to your front harness lines (to help tip the rig further forwards)” (G, Cribb 2005) This proves how important hand grip positioning is. 

From the two videos I can identify that the athlete has their hand grip around shoulder width apart, this is a positive as it shows that the power can be transferred into the rig. However the rig is lent backwards and sheeted out. This rig positioning will be the cause of the hand positing, from this I can see that both hands need to move forward around 2 hands in distance as this will allow the rig to be brought forward, by the rig being brought forward it will allow the power to transfer better through the rig having a higher beneficial effect for the athlete. The elite athletes hand positing creates a upright and sheeted in rig, this shows that they have, overtime, perfected their hand positioning in order to allow the rig to be in the most beneficial position. 

As my athletes hand positioning isn't 100% perfected this caused the rig to be in a less beneficial position, if this athlete was to race against an athlete that had perfected their grip positioning then it will give the first athlete a disadvantage as they will waste a higher percentage of energy, this is because the energy they create will not transfer through the sail as efficiently, therefore this athlete will have to work harder for longer as the energy transfer is less than the individual with the correct grip positioning who could work for a shorter period as the effects that they create will be higher. 


This could effect the athlete during competition circumstances as if they don’t create the full efficiency of pumping that there seed increase will be less than the other competitors. As mentioned perviously this could cause them to lose places throughout the race, even though they would be working hard. This could be frustrating for the athlete as they will not be creating the gains that they intended during the racing. therefore this grip positioning needs to be improved in the near future, as this small/minor change will allow the athlete to create a bigger speed increase through their pumping whilst not increasing their work rate, therefore working more efficiently around the course. 

Technical Components

The four technical components I will be looking into include:
  • Balance 
  • Body Positioning 
  • Grip (on the boom) 
  • Body stance 

Whilst looking into the following I used the elite level comparison again the athlete I looked into. This athlete was Andrew Brown, RYA Youth Squad member and current RYA Youth National Championships. The videos I used were taken at a Youth Squad training camp. 

From comparing the athlete to the elite model it can be seen my athletes balance isn't as strong, from the video recording it can be seen that my individuals feet move around the board at a higher rate than the elite athlete. This increase feet movement is caused by the individual trying to keep up their balance during the movement. The small feet movements around the board will have a negative impact of the effect the pumping should create, this negative impact is caused by their small feet movements messing up the trim of the board which will slow the individual down reducing the productivity of pumping itself. 

According to research they have seen that “balance forms our framework” (S,Bornhoft,2008), this shows that balance is vital in windsurfing and will allow every movement to be at an increased standard. Similar to this the balance, as mentioned before effects the trim negatively making the board either windward or leeward tilted, this tilt will effect the angle of sail as whatever rail is engaged the most will cause the board to head this direction, for example if the windward aril is engaged to much as to the feet moving off the centreline due to loss of balance then the board will begin to head further into the wind. Possibly causing the board to stall and lose all the speed gained by completing the pumping movement. Research also proves that “A flat trim is a fast board” (S,Bornhoft,2008), this means that it is vital for the individual to keep the board flat during the pumping movement in order to get the best speed increase. 

As my athletes balance standard isn't as high as it should be this will not only negatively effect the movement itself but it could also effect their positioning against their opposition during the races. Pumping is a technical movement used in all wind speeds that allows the individual to increase the wind flow through the sail thus allowing their overall speed to increase. As the individuals balance is having a negative impact on the pumping effect, this could cause the athlete to have a less of a speed increase compared to the other individuals which could result in the athlete loosing positions. As this balance has the possibility of effecting their race positioning it could also cause the athletes to have some psychological changes linked to this. As balance is such a small aspect of pumping yet has a dramatic effect this could cause the athlete to have feeling of frustration as they cannot improve it over a sport period of time. This frustration could cause them to begin to pump in anger and frustration if other begin to overtake them, this anger/frustration pumping is extremely bad for speed and sailing angle which will cause them to lose even more places, which is creating a downwards spiral. 

If the athlete were to improve their balance this will cause the overall productiveness of the pumping movement to be improved as the improved balance will allow the athlete to keep their feet positioning still, this still feet positing will allow the trim to remain flat and a flat board will allow the athlete to accelerate quicker and keep their speed up whilst completing the movements. This increased efficiency of pumping will increase the chances of the athlete gaining/taking places around the course. 


















Methodology of my research.

To record my data, I needed to film the subjects to have a record of the movements. I recorded my data using a camera, steading my arms by using a platform to rest my forearms upon. By striding the camera it ensure tat the angle wouldn't change during the recording as this would effect my data results. As my recording was needed to be completed on water this increased the difficulty in terms of accuracy and steadying of the camera angle as the boat was continually moving across the water, however this was minimised by being able to steady my camera angle. This help reduce the parallax and perspective error that could have occurred during the filming as it ensured that the angle and distance of the object stayed the same throughout the whole video. My athletes movements needed to stay parallel to the camera throughout the movement. If I didn't take into account the parallax and perspective error then it would be likely that my measurements wouldn't be correct and give a correct representation of the athletes performance which would have a negative effect if I needed to feedback on their performance from the data collected. 
Parallax error is the shape/size of an objects movement across a camera or a field of view changes. Perspective error is when objects seem to get bigger/smaller as they move to/from a view of a camera. 

During the recording I also used scaling to ensure that my measurements correspond correctly. Scaling a measurement in the field of view and within the plane of interest and this plane should be in the same plane as the movement being used in the study. Using scaling allows the calculation of a relative scale for all future measurements from that precise camera location, making all the measurements correct as the scale will keep everything equal. To ensure that my scaling is correct I will ensure that the movements being recored  take place in the same plane that the scaling was placed. For my recording as it was on water I used the board as my horizontal plane, this measurement equalled 93cm, the sail was used as the vertical scaling which measured 519cm. 


To help with the measurements of the athlete I placed joint markers on my athlete on the femoral Epicondyle, Greater Trochanter,elbow, Acromion Process and trunk. These markers are used to ease the location of the individuals joints during the recording and analysation. The markers should stand out against the background to ease the location finding of the joints under surveillance. However as the recording was taken place on the water his caused some of the markers to wash off, this caused me a disadvantage when analysing my results as it was more difficult for me to locate the specific movements of the joints are they were not clearly marked with the specific markers. 

Thursday, 3 March 2016

Racing Comparisons




Notational Analysis


Windsurfing-Notational Analysis

 

Tacking:

Lap
Successful
Unsuccessful
1
||
|||
2
|||
|

 

Lay lines:

Lap
On
Over  
1 Upwind
 
|
1 Downwind
|
 
2 Upwind
|
 
2 Downwind
 
|

 

Work Rate (over 30 second period):

Lap
Times recorded
1 Upwind
||||
1 Downwind
|||
2 Upwind
||||||
2 Downwind-Finish
||||||

 

Gybing:

Lap
Successful
Unsuccessful
1
||
||
2
||||
|

Thursday, 11 February 2016

Biomechanics -Proposal


During my analysis in windsurfing I will be looking into 3 different areas within the race. These are;

Tacking,gybing and work rate. In order to look into these criteria I will be measuring if they are

successful or unsuccessful (Tacking/gybing). A successful gybe/tack can be measured on the

effect it had on the other sailors and wether the tacked/gybed into better areas of pressure. ‘A good
tack is a tack where you continue to make maximum progress upwind. The aim is not to tack as

quickly as possible, or to come out as fast as possible, but to continue getting closer to the

windward mark as fast as you can”. (J, Emmett 2008) I will also measure the amounts of tacks/

gybes on Port (left) and starboard (Right) to see the amounts of tacks/gyves per beat/downwind.

Work rate will be measured in the amount of pumping (movement of sail and body together to

increase speed) over a time period of 30 seconds which I will mark down.



To analyse these criteria I will be videoing 1 individual over 2 separate races (windward/leeward

courses). When I analyse the data I would expect to see that f the individual has a higher success

rate in their tacks and gybes and higher work rate the better the result obtained at the finish. I will

be videoing the race instead of doing notational analysis during the race as I feel that this will

allow me to look more carefully into the race, because if I took the notational analysis during the

race it would be a higher possibility that I would miss certain aspects of the race that would be vital

to the end analysis.



The research I will be using to help with my analysis will be books including (RYA Tactics, 2007)
and (Be Your Own Sailing Coach, 2008) Within these books there are sections that will help me

analyse the races and help come to a conclusion. These sections include things such as “Upwind

tactics- Covering” and “effective board handling”.