dynamic touch of effective golf swing

DYNAMIC TOUCH OF EFFECTIVE GOLF SWING

Wangdo Kim, Antonio Veloso, Maria Machado, Veronica Vleck, Liliana Aguiar, Silvia Cabral

and Filomena Vieira

Biomechanics Laboratory

Faculty of Human Kinetics

Technical University of Lisbon

Estrada da Costa, Cruz Quebrada, Portugal

Introduction

We are revisiting the classic doctrine of “the

significance of left-hand extension during a golfer’s

downswing (Kim 2007).” Recent studies have

suggested that the inertia tensor, a physical property

whose values are time- and coordinate-

independent, may be an important informational

invariant that is used by the proprioceptive system

to control the movement of limbs. We use this

‘dynamic touch paradigm’ to explain why much of

traditional golf instruction has stressed the

importance of a neutral left wrist position,

classically called the ‘flat left wrist. We found that

a skilled golfer may achieve a stronger relationship

between perception and action in terms of their

correlation. The implication of our preliminary

findings about wobbling inertia with respect to the

functioning of the ‘flat left wrist’ are discussed.

Methods

We chose the club’s Instantaneous Screw Axes

(ISA)(Kiat Teu and Kim 2006; Kim and Sean

2011) and principal axes of inertia (e3) (Pagano and

Turvey 1995) and used their instantaneous

successive correspondence during swing as

generating manifolds for the perception to action

diagram. The test conducted to correlate perceptual

learning to skill level was presented as a so-called

‘perception to action’ spatiotemporal diagram that

is based on the two ruled surfaces generated in

terms of 3e � the perceptive information and ISA –

the corresponding actions of players. The 3e traced

out a one-parameter family of ruled surface as the

segment displaces.

Results

The profile of e3, indicative of the correct swing

plane, showed different forms in the expert and

non-expert player: Player A produced a

perturbation in e3 whereas player B produced an e3

shape more uniformly aligned to the path of ISA

(Figure 1 and 2). Greater congruency was observed

in the alignment of the two surfaces in Player B

compared to player A. Moreover, by virtue of

positioning the ISAs alongside the e3 of the club,

Player B achieved such a skilled motion that the

ISAs could be somewhat connected with the

principal inertia axes 3e .

Figure 1: Player A: lesser skilled player.

Figure 2: Player B: Expert player.

Discussion

The perception to action diagram could measure the

disturbing patterns of player-specific swing as a

consequence of a club’s wobbling inertia. Basically

this means that our computational framework offers

a more accurate player-specific model over a

generic model.

References

Kim W. 2007. Response to letter to the editor.

Journal of Biomechanics 40(1):225-225

Kiat Teu K, and Kim W. 2006. J Biomech

39(15):2857-2862.

Kim W, and Sean SK. 2011. Comput Methods

Biomech Biomed Engin in press.

Pagano CC, and Turvey MT. 1995. J Exp Psychol

Hum Percept Perform 21(5):1070-1087.

Presentation 1018 − Topic 41. Sport biomechanics S621

ESB2012: 18th Congress of the European Society of Biomechanics Journal of Biomechanics 45(S1)