jumping
*Any time a person or object is launched into the air
Ex- jumping, diving, gymnastics, throwing, or striking
Goals:
- maximum height
- maximum distance
- hit a target?
Biomechanical Factors of Jumping
1. Distance
· Distance = Horizontal velocity x Time-in-air
2. Speed (time in air)
· Vertical velocity at take off
· Starting height
· Small time in air- vertical velocity low (field hockey shot)
· Long time in air- vertical velocityl high (gold, football kick, acrobatic- more time in are for flips)
3. Accuracy
· Distance forward/ sideways
· Exact right speed and right angle and right projection height
· Control distance, sideways motion
4. Height
· Vertical velocity at toe off
· Starting height
Note:
Once in the air, direction cannot be changed.
· Can move body position but will move around center of mass
· If do move body one way, another body part will move in opposite direction to balance around COM
· Therefore, observe what is happening before being in air to prepare for this
Critical Features · Want maximum toe off distance, projectile distance, and landing distance
· In order to see how to improve each, look at the phases individually
a. Take off Distance
· Get full hip, knee, ankle extension at toe off
· Arm swing- full forward
· Center of mass position high in body
· Momentum- pull body forward
· Height/ body proportions
· Angle of push- low angles at toe off
b. Projectile Distance
· Consider “Distance= Vhoriz x time-in-air”
· Time-in-air= Vvertical and Starting Height
· Force against ground
· Countermovement
· Arm swing back
· Triple extension (hip, knee, ankle)
· Arm swing forward
· Angle? Want less than 45 degrees in order to push COM forward. Higher the angle, the more gravity will work against you
· Too low? Will affect time in air and friction
· Research shows approximately 30 degrees may be optimal angle
· Displacement force is applied through
· Push down on ground, ground pushes up
· Bigger distance your body moves through while pushing off the ground = more velocity
· Start lower (not too low)
· Go through full ROM
c. Landing Distance
· Rules: want to stick the landing
· Feet in front of COM (not enough v. too much)
· Balance purposes
· Arms forward or a jackknife type position
Observation Plan
- Watch toe off and legs
- Overall jump
- Peak in air to see angles
- Analyze from the side
- Measure distance with tape measure in feet
jumping_checklist.docx | |
File Size: | 11 kb |
File Type: | docx |
Evaluation Plan:
· Toe off speed and angle
o More speed is better than worrying about angle
· Big countermovement (from all joints)
· Speed you push through movement
· Sequencing of joints (proximal à distal)
· Arm swing- back with countermovement and drive forward with extension
· Symmetry and control of limbs
· Width of legs- bigger base of support for balance
o Too big loses power generation, changes angle of force production and changes the muscles being recruited
· Head forward- eyes forward, head more parallel to ground
· Toe off speed and angle
o More speed is better than worrying about angle
· Big countermovement (from all joints)
· Speed you push through movement
· Sequencing of joints (proximal à distal)
· Arm swing- back with countermovement and drive forward with extension
· Symmetry and control of limbs
· Width of legs- bigger base of support for balance
o Too big loses power generation, changes angle of force production and changes the muscles being recruited
· Head forward- eyes forward, head more parallel to ground