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Contents Introduction Selection of skill Page No: Description of model performance Related mechanical principles Analysis of data Suggestions for improvement Evaluation of results Conclusion References Bibliography 4 5 7 8 9 10 As a sports coach, analyzing performances is a task you carry out on a day to day basis. For this outcome I will observe a performance of a specific skill and compare it to a model performance. After analyzing the performance, I will make suggestions for improvement and evaluate the results.
I have chosen to observe and analyses the skill of a plough turn of a performer at an indoor ski slope. Plough turning is where a skier learns to control their speed with the snow plough and use the plough to change direction. This skill is taught to beginners. The model performance according to BASIS (British Association of Snowstorm Instructors), would look like this; long . From this model diagram, we can see that the skiers weight is forward and he is always facing downhill. It is the outer leg and foot that steer the ski.
The skier varies pressure on each ski during the plough at different times and this is what causes the skis to change direction. The effectiveness of the turn depends on where the reassure is applied to the ski. The most effective way of pressuring the ski is through the ball of the foot. The leg bends from the ankle, flexing the ankle forward so that the shins press into the tongue of the boot. Long. In this next image, we can see the outside leg begin to start the ‘rise’ and fall’ action. This action takes place to manage the pressure against the outer ski as the turn progresses.
The turn is then recovered by stretching the legs and steer into the next turn. The hand position is out inferno of the skier and the tops of the ski poles visible out the corner of each eye. A snow plough turn consists of a range of mechanical principles that can be analyses. There are many forces that act on the skier in this skill. Going down the hill pulled down the hill by gravity acting parallel to the slope. When turning, centrifugal force pulls the skier away from the centre of the arc of the turn, to continue the turn the skier has to resist this pull.
Forces working against the skier would be air resistance and friction between the skis and the snow. The above image is a skier working on balance. It shows the direction of forces working on the skier and the centre of gravity (COG) of the skier. The COG is different for every individual due to their individual mass. The COG also moves when an object changes shape therefore it moves throughout the whole skill of the plough turn. To get maximum velocity, the skier needs to use Joints in order of largest to smallest.
A skier needs to use ankle, knee and hip Joints together but the hip must always be inside the plough turn for the other Joints to work effectively. Impulse is defined as force multiplied by time. Impulse is the skiers work energy added to the forces of the turn. Some of this energy is potential energy. This is stored n the ski and boot when moving across the hill in the plough turn. When released and the plough turn is initiated, it is then turned into kinetic energy. Throughout the plough turn there are two types of motion, angular and linear.
Linear motion takes place when the skier is going in a straight line with their skis across the hill. This then turns into angular motion when the skier initiates the plough turn and the body moves around the axis of rotation in an arc. When analyzing my performer, he has some good points and some bad points, firstly his balance is good and not too far back and he is showing the beginnings of edging is skis in the plough turn. He Just needs a little separation from his upper and lower body. His bottom half is quite good, he Just needs to move his head more over the downhill ski, keeping the weight more down the hill.
He has a tendency to lean into the turn which is reducing the efficiency of his good angle in his lower leg and affecting his centre of gravity. I would also change his hand position, his hands are too high and too far forward. If he is not careful, this will actually push his weight backwards. The correct position is more around the waist and more relaxed. By ringing the hands down and more level with the body, this will encourage him to lean a little forward with his whole body and bring his rear in a little, which will help with the initiation of the turn.
To evaluate this performer, for his next steps to complete snowplow’s effectively, I would focus on starting the turn by working on edging both skis the same during the plough turn, the more edge the better. He should try and keep his balance 60/40 to the outside ski, and let the ski turn him, not ankle rotation. He should constantly review his performance with an observer, having omen analyses his level of skill then make a plan of what needs to happen next. The performer then needs to implement this plan and evaluate it and see whether the skill needs worked on or if the skill can be progressed.
With the above plan in mind and evaluation with the performer, he can now go and implement these changes to which will produce more efficient turns for the performer. Through researching sports mechanics, I have found many useful tips for analysis in both my personal performance and as a coach for my performers. These are very transferable skills throughout all sports and I feel that by researching mechanical reminisces, I have become a more knowledgeable coach and can offer a lot more help to my performers in coaching skills.
Using the stages of analyses, plan, implement, do and review will now be the main basis of any coaching I undertake. I feel this to be an easy yet detailed way to teach any skill in any sport where the performer is always working towards their desired outcome in manageable stages. This research has made me more aware as a coach of common problems to look out for in beginner skiing, problems that before I might not have looked at fixing but I know realism how it can contribute to problems later on in the performers skiing.