The Application of Sports Science to the Golf Swing
By Eanna Rushe MS, CSCS, MES
Introduction
At the
elite level the full golf swing is a marvel of science and technique. We look at professionals on the PGA and LPGA
tours and wonder how they drive the ball so far. There are many contributing factors including
equipment, physical conditioning and of course, raw talent. Less obvious is the
biomechanics of the golfer’s motion.
Biomechanics
is the analysis of human motion that blends physics and physiology. It allows us to measure movement patterns and
body segment speeds in the golf swing.
For example, if you videotape your golf swing you don’t know how fast
your hips are rotating or how fast the club shaft is releasing. Doing a biomechanical analysis of your golf
swing allows us to quantify your golf motion in terms of how fast each body
segment is moving, how you are creating power and if there are significant
power leaks. When you look at a
biomechanical model of a tour pro or long drive champion it becomes pretty
apparent why they drive the ball so far.
Their motion is highly efficient with very little power leakage.
Power Generation
Process - Kinetic Link Concept
The
kinetic link (sometimes referred to as the kinematic sequence) is the concept upon
which speed or power is created. This
concept applies to all hitting or throwing sports and it involves
speed/momentum transfer from the large body segments to the smaller body
segments. The golf-specific kinetic link
can be visualized as a system composed of four segments and three links. The segments are the hips, the shoulders, the
arms and the club shaft. The links are
the muscles that connect each segment.
For example, the trunk muscles connect the hips segment to the shoulders
segment. Before the backswing is
completed efficient golfers are already starting the downswing from the ground
up. As their feet push into the ground
forces are created that starts to accelerate their hips towards the target. This should not be interpreted as a big, wild
leg drive. In fact quite the opposite is
happening. It is a very tight,
controlled motion. Once the hips reach
their maximum speed they start to slow down or decelerate. This “braking” action transfers speed to the
shoulders segment, which accelerates to a maximum value usually twice that of
the hips. As the shoulders segment
reaches peak speed they start to decelerate.
Speed is now transferred to the arms, which accelerate even faster. As the arms are approaching impact they
decelerate rapidly transferring a huge amount of speed or momentum to the club.
The club then releases or uncocks into impact with maximum velocity. It is interesting to note that the arms reach
peak speed before impact not at or after impact.
Eanna uses 3D technology to analyze the "kinetic link."
Power Leaks
Common
power leaks include:
- Hip Slide
- Hip Spin
- Arm-Push
A Hip
Slide occurs when the hips move laterally or slide from right to left
during the downswing. No rotational hip
speed is created. Often times the hip
slide is accompanied by a spine tilt to the right side. Now the muscles on one side of the trunk are
lengthened while muscles on the opposite side of the trunk are shortened. This asymmetry causes inefficient power
generation.
A Hip
Spin occurs when the golfer tries to excessively rotate the hips on the
downswing. Now the lower body outraces
the upper body and too much lag is created between the hips and the
shoulders. The potential energy that
could have been used to accelerate the shoulders is wasted and power is lost.
An “Arm-Push”
pattern occurs when the arms do not decelerate or slow down rapidly before
impact. The arms are forcing or pushing
the club through impact. In many cases
the arms reach peak speed after impact.
This action disrupts the normal speed transfer process from arms to
club. The club release speed is
significantly decreased and potential power is lost.
Common
Misconception
Hold the Angle - When we look at the motion of
efficient golfers on videotape it appears that they are “holding” the club
shaft in a cocked position deep into the downswing. Many amateurs in an attempt to create more
power try to emulate this action. What
you have to understand is that efficient golfers do not manufacture or try to hold
this cocked position. The arms
accelerating around the axis of the trunk on the downswing create this club lag
or cocked position. When the arms
decelerate before impact speed is transferred to the club. The club accelerates and the angle between the
arms and club shaft increases rapidly into impact.
About the Author: Eanna Rushe is the founder of
BioSport Technologies located in
The author would like to acknowledge Chris Welch for biomechanics references.
The articles at GolfFitnessProducts.net
are for informational purposes only and are not intended to substitute
for direct examination and exercise prescription by the appropriate
health professional. It is strongly recommended that you do not
perform any exercise program without the consent of your personal
physician.
