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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.
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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 THROW Pattern PUSH Pattern
Constraints: Throw/Push Continuum • Mass of projectile • Volume/Size of projectile • Shape/Profile of projectile • Target Area for projectile • Strength/Power of person • Skill of person
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 OPEN Kinetic Chain CLOSED Kinetic Chain
Throwlike Patterns • 1. Proximal Parts Move First • 2. Distal Parts Lag Behind • 3. Achieve either : maximum distance [ HORZ or VERT ] OR maximum velocity
Fig J.1 page 338 1. segment A is accelerated which gives L to entire system: segments A, B, and C 2. A rotates cw while B and C lag behind 3. A is THEN decelerated by muscle T 4. To conserve L, B accelerates cw THEN decelerates, C then accelerates cw
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 entiresystem LL= mk² x OR L = I
Sequential Motions • 1. proximal/massive segments move first givingL 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 • See FIG 15.16 on page 514 • VB spiker abducts hip and/or flexes knees to I (I = mk²) in lower extremities • turntable demo
Flexion/Extension Protraction/Retraction Abduction/Adduction Medial/Lateral Rotate Pronate/Supinate Inversion/Eversion Lever Motions Wheel-Axle
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 • see FIG J.6 on page 346 and FIG J.12 on page 352
THROW / PUSH for Speed and Accuracy FIG J.8 page 349 FIG J.10 page 350
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