Initiating Rotation while Airborne

1
Initiating Rotation while Airborne

• 1. Reaction Rotation
• 2. Cat Rotation
• 3. Twist from a somersault

2
Reaction Rotation to Initiate Twist Rotation

• while airborne L is constant and ST 0
• ? rotation action in one direction causes a
  rotation reaction in the opposite direction
• 360 full turn/twist requires 8 series of steps
  alternating I during arm swing/recovery
• HJ clearing trailing body parts straddle, flop

3
Cat Rotation to Initiate Twist Rotation
? Page 505 FIG 15.8
? Page 503 FIG 15.6
4
Cat Rotation to Initiate Twist Rotation
180 half turn/twist requires3 steps as follows

1. A. place lower upper axes at an ?
2. B. twist upper body, lower body has small
   reaction
3. C. twist lower body, upper body has small
   reaction

page 505 FIG 15.8
5
Somersaultto Initiate a Twist

1. from symmetrical position, initiate layout back
   sommie(establish L about ML axis)
2. move to asymmetrical position drop rt. arm

- this reduces I on rt. side of body ? ? ? about
ML axis on that side - nutation (tilt of body)
results and a twist begins
page 506 FIG 15.9
6
Somersault to Initiate Twist Rotation

• most effective of the 3 methods of initiating a
  full twist (360)
• multiple twists (720 rotation or more),
  performer usually initiates some of the twist
  from the ground (Freaction) in addition to the
  airborne maneuvers(symmetrical to asymmetrical
  during the somersault action)

7
Kicker ramp places body in position for g to
apply a T to initiate a back sommie
8
Left photo? symmetrical
Right photo? asymmetrical
9
Altering k radius of gyration
page 511FIG 15.13atight tuckelayout
10
Altering k - radius of gyration

• TABLE 15.1 on page 510- read across from left to
  right
• Example from Table 15.1
• moving from position a to position e ?
  diminishes by almost 75? from 1.00 to 0.28

11
Manipulating Rotations in Sport
12
Manipulating Rotations in Sport
13
Manipulating Rotations in Sport
page 515 FIG 15.17
14
Manipulating Rotations in Sport
More elongated Slower Rotation about ML
axisLess elongated body Faster
RotationReaction Rotation to Clear Trailing Body
Parts
15
Gymnastics Tumbling SkillsLess Skilled
Highly Skilled

• high vvert due to ? power ? takeoff ?
• ? more air time
• high ? due to? power ? I _at_ takeoff
• smaller k in flight

• low vvert due to ? power ? takeoff ?
• ? less air time
• low ? due to? power ? I _at_ takeoff
• larger k in flight

16
Sample Tape Aid in Prep for Test

• 1 copy of a sample tape located in each of the 2
  video viewing booths (VCR in middle booth not
  working)
• booths located in Thames Hall room 2120A across
  the hall from the Computer Lab
• each booth can hold up to 3 persons

17
ABOUT THE VIDEO EXAM

1. Exam held in Natural Science Room 145
2. Video Exam is 45 minutes long covering
3. 9 skills, 3 questions per skill (n27 questions)
4. 5 minutes allowed to answer 3 questions per
   skill
5. Exam Value 25 of final course grade