1. Rotations Free of Support
Most common in Dance, Diving, Figure Skating, Gymnastics, Trampoline
ML Axis see [Figure 15.2a]
L axis see [Figure 15.2b]
AP axis see [Fig. 15.2c]
flight path of CG takeoff
airborne segmental motions do not change CG flight path [see Figure 15.1 on page 494

2. Rotations about ML Axis - page 495 FIG 15.2a

3. Rotations about L Axis - page 496 FIG 15.2b

4. Rotations about AP Axis - page 496 FIG 15.2c

5. CG Flight Path determined @ takeoff page 494 FIG 15.1

6. I is rotational inertia - a body’s resistance to change angular motion
L: Angular Momentum
L = I 
 is angular velocity
I is rotational inertia - a body’s resistance to change angular motion
I = mk² (mass x distance² of mass from axis of rotation)

7. L stays constant while airborne  changes due to changes in I
Conservation of L
L stays constant while airborne
 changes due to changes in I
k changes as body moves to pike position then back to a layout position
Fig I.5 page 329

8. L = I in Body Rotations I (rotational inertia) = mk²
Angular Momentum = Rotational Inertia x 
I (rotational inertia) = mk²
1. [m] mass of performer (does not change)
2. [k] radius of gyration of performer’s mass
3. [] angular velocity of performer’s rotation
distribution of m is key feature

9. L constant while airborne
individual segments may redistribute total body’s L
rotate arms forward, trunk rotates backward so total L remains constant
LJ - rotate trunk downward and legs move upward
L is takeoff
the entire body has L
L remains constant during flight until an external T acts on body [e.g. floor, water]

10. Small segment requires  
Entire body/system has a magnitude of L takeoff L = I  or L = (mk²) x ()
takeoff due to magnitude of both I and 
takeoff due to magnitude of T applied
m and k of arms much smaller than total body
to slow/stop trunk rotation, arms rotate with  [arms m and k much less than trunk m and k]

11. RIGHT-HAND THUMB RULE method of determining vector direction
curve fingers of right hand in direction of rotation
right thumb points in vector direction of L & 
see Figure E.5 on page 113
see Figure 15.4 on page 498

12. RIGHT HAND THUMB RULE
FIG E.5 page FIG 15.4 page 498

13. Initiating Rotations from the Ground GRF (ground reaction force) applied eccentrically
FIG 15.5
Pg 500

14. Initiating Rotations from the Ground GRF (ground reaction force) applied eccentrically
FIG I.1b
Pg 327

15. Initiating Rotations from the Ground GRF (ground reaction force) applied eccentrically
FIG I.2
Pg 328

16. Initiating Rotations from the Ground GRF (ground reaction force) applied eccentrically
FIG I.3 Pg 328

17. Initiating Rotations from the Ground GRF (ground reaction force) applied eccentrically
Pg FIG 12.5

18. Initiating Rotations from the Ground GRF (ground reaction force) applied eccentrically
page FIG 12.10