155

9

(Biomechanics of Airborne Activities)

1. 2. 3. 4. 5.

5.1

5.2

5.3

5.4 Twist Somersault

9

1. 2. 3.

1.

2.

3.

/

1.

2.

3.

851346 2 156

4.

1.

2.

3.

.

157

9

(Biomechanics of Activities which the Body Rotates Free of Support)

Twist

(Mediolateral axis) -

(Anteroposterior axis) (Longitudinal axis)

(Realignment)

9-1

layout

tuck layout

851346 2 158

9-1 (Wpendy et al., 2013)

layout tuck

(Angular momentum) 3

(Radius of gyration)

(Angular velocity)

9-2

layout

tuck

2

(Inertia: I)

159

9-2

(Kreighbaum, Barthels, 1996)

I = mk2 (1)

I

m

k

( 9-3)

3

L = 0

Larms + Llegs + Ltrunk = 0

I11 + I22 + I33 = 0

851346 2 160

(+30) + 0 + Ltrunk = 0

Ltrunk = -3.0 angular momentum units

9-3 (Kreighbaum &

Barthels, 1996)

2

1.

Eccentric torque

Moment (M) = Torque () =F x S F

S

161

2.

3.

S = at2

S

a

t

4.

5.

6.

4

1. (Amplitude)

2

- (External amplitude)

( 9-4)

851346 2 162

9-4 2 (Adrian & Cooper, 1995)

- (Internal amplitude)

9-5

2. (Segmentation)

14

163

3. (Closure)

9-6

4. Peaking

Somersaults Twists

2 3

1. (Ground reaction rotation)

( 9-7) Somersault ( 9-8)

851346 2 164

9-7 (http://shannonjusticeforall.wordpress.com/2013/04/21/stop-

drop-roll)

9-8 Somersault (http://gratewire.com/topic/newt-gingrichbusted-on-his-flip-flop-

on-libya)

1

9-9

2

165

9-9 2 (Kreighbaum &

Barthels, 1996)

2. (Reaction rotation)

3. (Cat rotation)

Modern twist (Biesterfeldt, 1974b)

Counter-rotation twist (Hery, 1975)

9-10 2 (

)

90

3

851346 2 166

( 9-10)

9-10 (McDonal, 1960)

( 9-11 a, b) ( 9-11 c, d)

9-11 (McDonal, 1960)

167

4. Twist Somersault

(Axis of momentum)

Somersault

2

- ( 9-12)

9-12 Twist Somersault (Kreighbaum & Barthels, 1996)

851346 2 168

Adrian, M.J., & Cooper, J.M. (1995). Biomechanics of Human Movements. 2nd

ed. Boston:

WCB McGraw-Hill

Biesterfeldt, H.J. (1975b). Twisting mechanics II. Gymnast. 46-47.

Hery, G. (1975). Mechanics of rotational movements. Paper presented at the Southwest

Gymnastics Clinic, Las Vegas.

http://gratewire.com/topic/newt-gingrichbusted-on-his-flip-flop-on-libya

http://shannonjusticeforall.wordpress.com/2013/04/21/stop-drop-roll

Kreighbaum, E., & Barthels, K.M. (1996). Biomechanics: A Qualitative Approach for

Studying Human Movement. 4th eds. MA: Allyn & Bacon.

McDonald, D. (1960). How does a man twist in the air? New Scientist. 237; 501-503.

Wpendy, S.B., Viren, T. et al. (2013). How to Do a Triple Front Flip. Retrieved from

http://www.wikihow.com/Do-a-Triple-Front-Flip

9

1.

2.

3.