throw pattern push pattern proximal segments in front of projectile with distal segments behind...
TRANSCRIPT
THROW Pattern PUSH Pattern proximal segments in front
of projectile with distal segments behind projectile
sequential for v curvilinear path mostly wheel-axle
all segments behind projectile pushing the projectile or load
simultaneous for F rectilinear path mostly lever motions
Movement Patterns - Related Skills Underarm Badminton Bowling Hockey Horseshoes Volleyball
Sidearm Baseball Discus Hammer Handball Squash Tennis Volleyball
Overarm Badminton Baseball Cricket Javelin Tennis Volleyball
Kick Football Rugby Soccer Swimming
Constraints: Throw/Push ContinuumMass of projectileVolume/Size of projectileShape/Profile of projectileTarget Area for projectileStrength/Power of personSkill of person
OPEN Kinetic Chain CLOSED Kinetic Chain
• Throw or Kick
• End Segment Free [e.g. hand, foot]
• sequential movement of body segments
• Jump or Push or Pull
• End Segment Restrained[e.g. foot, hand]
• simultaneous movement of body segments
Throwlike Patterns
• 1. Proximal Parts Move First
• 2. Distal Parts Lag Behind
• 3. Achieve either :maximum distance [ HORZ or VERT ]OR
maximum velocity
1. segment A is accelerated which gives 1. segment A is accelerated which gives LL to entire to entire system: segments A, B, and C system: segments A, B, and C2. A rotates cw while B and C lag behind2. A rotates cw while B and C lag behind3. A is THEN decelerated by muscle T3. A is THEN decelerated by muscle T
4. To conserve 4. To conserve LL, B accelerates cw THEN , B accelerates cw THEN decelerates, C then accelerates cwdecelerates, C then accelerates cw
Fig J.1
page 338
End Point v due to decreasing r• See FIG. J.1 on page 338 L= mk² x • initial k is from axis “a” to top of segment C
• when segment A decelerates, the k changes to the distance from axis “b” to top of segment C
• when segment B decelerates, the k changes to the distance from axis “c” to top of segment C
v = r • final velocity of hand or foot or implement @
release/impact determines projectile v
• r = d from the axis of rotation [e.g. joint] and the contact point of release/impact
• see FIG J.12 on page 352 with regard to r
Kinetic Link Characteristics
• system of linked segments with a fixed base and a free open end
• more massive segments @ proximal end• least massive segments @ distal end• initial motion caused by T applied to base
• T gives entire system L L= mk² x OR L = I
Sequential Motions• 1. proximal/massive segments move first giving
L to entire system • 2. external T decelerates proximal segments• 3. to conserve L, next segment, which is less massive,
accelerates with rotation now occurring about a new axis and a smaller k
• 4. Each successive segment/link accelerates achieving than previous segment due to both m and k getting progressively smaller
Airborne Reaction Rotation
while airborne, if a person initiates rotation about any axis,
a reaction rotation will occur in the opposite direction about that same axis
due to the law of conservation of angular momentum
turntable demo
Minimizing Airborne Reaction Rotation
VB spiker abducts hip and/or flexes knees VB spiker abducts hip and/or flexes knees toto
II (I = mk (I = mk²²) in lower extremities ) in lower extremities
Lever Motions Wheel-Axle
• Flexion/Extension
• Protraction/Retraction
• Abduction/Adduction
• Medial/Lateral Rotate
• Pronate/Supinate
• Inversion/Eversion
Wheel-Axle Motions• muscle T rotates a bone which becomes an axle
• the wheel is the adjacent segment positioned at an angle to the axle
• the wheel r (radius) is modified via flexion/extension or adduction/abduction
Small Wheel
Big Wheel