qualitative analysis of the inward pike dive
Goals:
- Diving is judged by points, so you want to maximize points with technique and form.
- Enter the water as streamlined as possible to have the smallest splash.
- Jump up and away from the board so you do not hit it on the descent.
- Pike at the peak of the jump.
Biomechanical Factors of an Inward Pike:
· Angular momentum is one of the most important biomechanical factors acting on divers. Angular momentum will be determined by:
o angular velocity- which is how fast the diver is rotating. This will be achieved by the jump onthe board (much like a countermovement in regular jumping).
o moment of inertia- which will include the mass of the diver and the distance the mass is from the axis of rotation. The pike position will minimize the moment of inertia because it keeps the mass and axis of rotation closer together than if the body was straight. Many divers are also slim and have relatively lower mass.
· Gravity, forces from the board, and friction from the board are also acting on the diver.
· Momentum is created on the board before the jump. The inward pike dive involves slowly oscillating the board before takeoff, followed by a countermovement. The countermovement involves flexion of the knees, hips, and ankles with an arm swing. The arms rise above then head and then circle behind the body and up at the release of the jump. The countermovement and arm swing helps raise the center of mass and create upward momentum for the jump.
· The divers don’t want to create more momentum than they need because it will actually hurt their dive. If they have too much angular momentum they will rotate more than they want to, and will not enter the water at an ideal angle.
· The diving board also helps create more torque for the diver than jumping off the ground or a solid surface. The diving board is springy and rests on a fulcrum so the diver can get as much torque as possible to jump with maximum height.
· The diver needs maximum vertical velocity to maximize their time in the air. This is necessary to help them complete their stunts and get their body in position to hit the water smoothly.
· Timing is essential in diving. For the inward pike timing of the countermovement, arm swing, jump, and change in body positioning are essential for success.
· The diver needs maximum ROM and flexibility to be able to get into the correct body positions.
Critical Features to Look For:
· The countermovement and the arm swing will determine the success of the skill because it produces the angular momentum for the enter dive.
· The body position and how close they get their center of mass to their axis of rotation (for their moment of inertia). Also, their body position in terms of ROM and flexibility.
· Body positioning throughout the dive and particularly when they enter the water.
· Overall timing of each step of the dive.
· Sequencing should be as follows: (illustration is also below)
o Heels of the feet slightly over the end of the board (back facing the water).
o Keeping your body completely straight begin oscillating the board with your ankles only.
o Once the board begins oscillating drop your heels and raise your arms laterally until they are completely extended over your head.
o As the arms reach full extension your heels should raise as well until you are on your toes.
o Now begin flexing your knees and hips (squatting down) and circle your arms behind you. This is the beginning of the countermovement. The “squat” should continue very deep until the hips are almost parallel with the board. (Which is not well illustrated in the picture)
o Continue circling your arms up and completely extend your ankles, knees, and hips to push off the board. The push off should be at about at 45° angle so you move up and away from the board. On the jump, your legs should be spread out slightly and arms out to your side. This will help slow your angular momentum so that you can pike, but not tuck.
o Immediately, begin to move your arms back and flex at the hips to begin the pike position.
o When your hips and torso are directly perpendicular the entry point in the water, begin to press the legs out of the pike in a completely straight position and raise your arms over your head.
o Grasp your hands over your head and flatten your palms so they strike the water surface flat. (Also not illustrated well in the picture)
o Lock your elbows and tighten your gluteus muscles and abdominal muscles.
o Enter the water completely perpendicular to the water to minimize splash.
· Angular momentum is one of the most important biomechanical factors acting on divers. Angular momentum will be determined by:
o angular velocity- which is how fast the diver is rotating. This will be achieved by the jump onthe board (much like a countermovement in regular jumping).
o moment of inertia- which will include the mass of the diver and the distance the mass is from the axis of rotation. The pike position will minimize the moment of inertia because it keeps the mass and axis of rotation closer together than if the body was straight. Many divers are also slim and have relatively lower mass.
· Gravity, forces from the board, and friction from the board are also acting on the diver.
· Momentum is created on the board before the jump. The inward pike dive involves slowly oscillating the board before takeoff, followed by a countermovement. The countermovement involves flexion of the knees, hips, and ankles with an arm swing. The arms rise above then head and then circle behind the body and up at the release of the jump. The countermovement and arm swing helps raise the center of mass and create upward momentum for the jump.
· The divers don’t want to create more momentum than they need because it will actually hurt their dive. If they have too much angular momentum they will rotate more than they want to, and will not enter the water at an ideal angle.
· The diving board also helps create more torque for the diver than jumping off the ground or a solid surface. The diving board is springy and rests on a fulcrum so the diver can get as much torque as possible to jump with maximum height.
· The diver needs maximum vertical velocity to maximize their time in the air. This is necessary to help them complete their stunts and get their body in position to hit the water smoothly.
· Timing is essential in diving. For the inward pike timing of the countermovement, arm swing, jump, and change in body positioning are essential for success.
· The diver needs maximum ROM and flexibility to be able to get into the correct body positions.
Critical Features to Look For:
· The countermovement and the arm swing will determine the success of the skill because it produces the angular momentum for the enter dive.
· The body position and how close they get their center of mass to their axis of rotation (for their moment of inertia). Also, their body position in terms of ROM and flexibility.
· Body positioning throughout the dive and particularly when they enter the water.
· Overall timing of each step of the dive.
· Sequencing should be as follows: (illustration is also below)
o Heels of the feet slightly over the end of the board (back facing the water).
o Keeping your body completely straight begin oscillating the board with your ankles only.
o Once the board begins oscillating drop your heels and raise your arms laterally until they are completely extended over your head.
o As the arms reach full extension your heels should raise as well until you are on your toes.
o Now begin flexing your knees and hips (squatting down) and circle your arms behind you. This is the beginning of the countermovement. The “squat” should continue very deep until the hips are almost parallel with the board. (Which is not well illustrated in the picture)
o Continue circling your arms up and completely extend your ankles, knees, and hips to push off the board. The push off should be at about at 45° angle so you move up and away from the board. On the jump, your legs should be spread out slightly and arms out to your side. This will help slow your angular momentum so that you can pike, but not tuck.
o Immediately, begin to move your arms back and flex at the hips to begin the pike position.
o When your hips and torso are directly perpendicular the entry point in the water, begin to press the legs out of the pike in a completely straight position and raise your arms over your head.
o Grasp your hands over your head and flatten your palms so they strike the water surface flat. (Also not illustrated well in the picture)
o Lock your elbows and tighten your gluteus muscles and abdominal muscles.
o Enter the water completely perpendicular to the water to minimize splash.
Observation Plan:
· Sagittal view is needed to examine the sequence of the dive and overall motion. Frontal view is necessary to examine the body and joint alignments particularly before takeoff.
· I would listen to the board and the water to get information about takeoff and entry.
· Look for overall “smooth” or “fluid” motion.
· Watch the overall motion first to get an idea of what they are/aren’t doing.
· Then key into each phase- countermovement, flight, and then entry. It will be hard to watch them all because it happens really fast.
· Sagittal view is needed to examine the sequence of the dive and overall motion. Frontal view is necessary to examine the body and joint alignments particularly before takeoff.
· I would listen to the board and the water to get information about takeoff and entry.
· Look for overall “smooth” or “fluid” motion.
· Watch the overall motion first to get an idea of what they are/aren’t doing.
· Then key into each phase- countermovement, flight, and then entry. It will be hard to watch them all because it happens really fast.
dive_checklist.docx | |
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File Type: | docx |
Evaluation Plan:
· Is the problem technique related or fear related? To divers, jumping towards the board is extremely stressful. Address psychological issues in conjunction with skill related issues.
· Break the dive into steps. A lot of divers use suspension training out of the water to get the steps down. I would break each section into steps and practice them out of the water, in a more controlled environment. Use video feedback here and in the water. When using suspension training it will be a little easier to fix technical problems, so utilizing it in a controlled environment may be beneficial.
· Fix timing and sequencing first, this will be the most crucial aspect to overall success of the skill.
· Address flexibility and ROM because divers need to be able to be completely straight and need maximum extension at all joints.
· Is the problem technique related or fear related? To divers, jumping towards the board is extremely stressful. Address psychological issues in conjunction with skill related issues.
· Break the dive into steps. A lot of divers use suspension training out of the water to get the steps down. I would break each section into steps and practice them out of the water, in a more controlled environment. Use video feedback here and in the water. When using suspension training it will be a little easier to fix technical problems, so utilizing it in a controlled environment may be beneficial.
· Fix timing and sequencing first, this will be the most crucial aspect to overall success of the skill.
· Address flexibility and ROM because divers need to be able to be completely straight and need maximum extension at all joints.