Data Distribution

WEIGHT TRANSFER PATTERNS DEPENDING ON GOLF SKILL LEVEL

Isao Okuda 1, Sema Kalaian 2, Charles Armstrong 1, and Hiroaki Yoshiike 3

1

Applied Biomechanics Laboratory, University of Toledo, Toledo, OH, USA

2

Research and measurement, University of Toledo, OH, USA

3

Institute of Physical Research, Co Ltd, Tokyo, Japan

E-mail: *******@***.***

INTRODUCTION

Biomechanical studies of golf, although Instruments: The weight transfer pattern

limited in number, have demonstrated during the golf swing was measured

that skilled golfers show more efficient using a custom designed portable force

patterns of motion and force application platform (Kyowa-Dengyo, Tokyo,

than less skilled golfers (Richard et al., Japan). This platform system consisted

1985). Since the down swing in golf of two separate footplates synchronized

lasts only a fraction of second, golfers with a video camcorder, by which

must rely on the stored memory of the vertical ground reaction force (VGRF)

motion to determine this phase of the was measured for each force plate. The

swing, rather than on sensory feedback. VGRF data was collected at 1000Hz,

This suggests that the phase that while the associated video data was

precedes the down swing, the recorded at 30 fields per second. The

preparation phase (address to top of the camcorder was positioned perpendicular

swing), may be crucial in creating the to the subject s frontal plane of motion

optimum conditions for a successful and was used to identify the specific

down swing. Information about this events during the swing.

phase, relating to the involved

movement patterns and the associated Procedure: Data collection took place at

weight shift, may be of great practical an outside driving range so that the

value. Therefore, the purpose of this complete ball flight from each trial could

study was to examine the weight shift be monitored. After a fifteen minute

pattern associated with the preparation warm up, the subject performed three

phase of a full-shot golf swing to full-shot swings with their own driver

determine how it differs between expert while VGRF and video data were

and novice golfers. collected. The best shot in the three trials

was determined subjectively and then

used for data analysis. During post-

METHODS

processing of the data, the trial was

Subject: Fourteen right-handed JPGA analyzed at four specific points

touring professional golfers (skilled identified by the video data, which

group-SG) and twelve amateur golfers served as a basis for the analysis in this

(unskilled group-UG, handicaps from 20 study. The four specific points were: (1)

to 35 stokes), ranging in age from 22 to address, (2) back swing (club shaft

45 years, volunteered to participate in horizontal to the ground), (3) top of the

this study. swing, and (4) ball impact.

1

Analysis of data: The subject s weight weight distribution change from the back

distribution between the two feet was swing to the top of the swing (p

converted into a percentage and

4.0

analyzed at the four specific points.

2.0

Because of this study s small sample 0.0

Percentage size, applying a nonparametric statistical -2.0 Skilled Unskilled

methods are needed. A nonparametric -4.0

-6.0

repeated measures ANOVA was used to -8.0

identify the difference between the SG -10.0

and UG group followed by -12.0

-14.0

nonparametric post-hoc tests to identify

Skill level

the points where the difference existed.

Figure 2: Changes in the right foot

RESULTS AND DISCUSSION

weight distribution from back swing to

Figure 1 illustrates right foot weight

the top of the swing

distribution across the four points, and

the associated analysis revealed a

Collectively these results demonstrate a

significant (p

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