KINEMATICS OF "PUMPING" IN THE DISCIPLINE OF WINDSURFING
20 July 2010: our National Nicola graduated in Physical Education. Of course we could not RIWmag not snoop in the content of his thesis. Ladies and Gentlemen here is the Dr. Spadea! (second part, here the first part)
“Result and discussion
Speed of sailboard - Table 1
grip compared to the breadth of the shoulders | Δ cruising speed in knots
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ less | 2.5
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Top | 2
______________________________ uguale | 4.3
As can be seen from the table 1 gait speed of a surf generated by pumping to handle equal to the width of the shoulders is the highest, follow the values of pumping less grip and finally those with superior grip.
Angular velocity - Table 2
grip compared to the breadth of the shoulders | ΔV Stern arm angle | ΔV bow arm angle
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ less | 99,7 (degrees/sec.) | 23,3 (degrees/sec.)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Top | 115,2 (degrees/sec.) | 60,9 (degrees/sec.)
_____________________________ uguale | 88,4 (degrees/sec.) | 23,8 (degrees/sec.)
The angular speed is considerably higher in Stern's arm. Stern's arm in windsurfing is the arm more interested by wind intensity, so impressed by the strength and sail changes in direction of the latter and so is what makes more changes of angle. The bow arm is less than these factors because, being placed closer to a fixed point where the tree, is more stable. Confirming as expressed by angular velocity data of the bow arm is greater in pumping top grip, When you perform a move in which the arms flexing much more than another two cases. With a higher grip compared to the breadth of the shoulders is limited rotary motion of the wing's inherent right and pumping in an attempt to take more air without rotary motion to increase the flexion of the arms is not getting good results anyway and executing movements that lead to fatigue. To follow the pumping less than grip shoulder width with an angular velocity on the stern of arm 99,7 degrees/sec. and an angular velocity on the bow arm 23,3 degrees/sec: This is a technical gesture allowing better turning movement up the sail and then a good this dislocation in the wind allowing you to generate a good speed. The lower handle does not allow the subject to give his maximum muscular strength. With the angular velocity of the arm of the stern of 88,4 degrees/sec. and angular speed of the bow arm 23,8 the pumping to handle equal to the width of the shoulders is the technical gesture in which he manages to have the best combination between rotary motion of the glider and power expressed by muscular groups thus generating the best gait speed.
Number of pumping per minute - Table 3
N. pump/min lower handle to the breadth of the shoulders | 46,51
N. pump/min higher grip to the breadth of the shoulders | 50,84
N. pump RPM handle equal to width of the shoulders | 46,15
The table 3 is further confirmation of what has been said so far proving that with a value of 50,84 pump strokes/minute during a pumping top grip to the breadth of the shoulders windsurfing sails at a speed of 2 nodes. With a value of 46,51 pump strokes/minute during a pumping to handle less than shoulder width windsurfing sails at a speed of 2,5 while nodes with a lower value of all other 46,15 pump strokes/minute during a pumping to handle equal to the width of the shoulders windsurfing sails to the most sustained speed of 4,3 nodes.
In conclusion the pumping to handle equal to the width of the shoulders he reach the sailboard of sustained speeds than the other two ways at the same time doing less repetitions of the gesture, demonstrating the technical gesture to be better executed with optimum grip. To perform a pumping correctly and profitably the grip of the hands on the boom must be approximately as wide shoulders, you have to have to sail a rotary movement in symbiosis with the forward-back created by extension-flexion of the arms and balance well with the weight of the body. In pumped the handle less than shoulder width the rotary motion can be accentuated even more but failing to express via muscle strength to narrow grip is not the best compromise between technique and strength. In the upper handle pumped to the breadth of the shoulders rotary motion disappears almost entirely and cause the obstacle created by the position of the body: so the only forward movement-behind fails to match the technical performance of the gesture with the optimal grip. In this thesis the foundations were laid in an unknown field in certain terms, rich in knowledge still to be acquired and is given the opportunity in the future to have a guide with scientific bases on the windsurfing and on this fundamental gesture.”
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