Biomechanics in Action: The Importance of Side-Bending at the Top of the Swing

By Chris Poulin

Attaining Effective Sidebend Ranges

Among the golf professionals with whom I’ve worked, it’s widely accepted that there needs to be some side-bending of the upper body at the top of the backswing. But why?

Without side-bending the movement would be similar to hitting a baseball off a tee. The amount of necessary side-bending, however, can vary depending on the shaft length of the club that you are swinging. For example, you would expect to see an increase in side-bending with a pitching wedge, and a decrease with a driver.

In the golf fitness industry, the amount of side-bending that we try to achieve is around 40 degrees. We use this number to create programs that are functional in developing rotary speed and power, but its reduction to a single target is also to some degree arbitrary. That is, K-VEST states that the average tour pro has a sidebend range of 39 to 45 degrees when hitting with a 6-iron. When training golfers, then, it would behoove us to look at human form and function in order to help them attain this position safely and efficiently.

What Biomechanical Analysis Reveals

In the images below you can see a compensatory position that most amateurs experience; it is termed a “flat shoulder plane,” and one can contrast it with the professional golfer shown on the right who is side-bending into an acceptable range. Anecdotally, I find that golfers with limited upper body sidebend have increased right sided lower back pain as a result of their right quadratus lumborum staying hypertonic.

Flat Shoulder Plane vs. Ideal Shoulder Plane


This type of movement is particularly challenging for right-handed players who, because of the normal asymmetrical form of the thorax and neurologic systems, are patterned to favor their right sides and want to maintain right side bending throughout the swing. So correcting any problems is not as simple as asking the golfer to achieve an optimum number—and voila!

The abdominal muscles of a golfer (as shown in the anatomical cross-section) are asymmetrical in their roles in the golf swing; couple that with the fact that the diaphragm muscle is bigger and happens to attach one vertebrae lower on the right, and you have a very good explanation for why we see right shoulders lower than left shoulders with right-handed players.

abdomen_1 abdomen_2 abdomen_3

Above you can see the abdominal area of two golfers, an amateur on the left and a professional on the right. Notice the difference in the right sides vs. the left sides, and check yourself in the mirror. If your left arm is farther away from your side and your right shoulder is lower than your left, the exercises that follow could help you achieve a better sidebend position at the top of your golf swing.

Objective Evidence and Practical Exercises

Using K-VEST, we can capture upper body sidebend data and train our clients how to become better at stretching their right abdominal wall and strengthening their left. Below you can review a typical finding for a patterned right-handed golfer. Take note of the upper body sidebend at the top and understand that, again, our goal would be to achieve around 40 degrees. The exercises that follow (reprinted with permission from the Postural Restoration Institute) will help you reach that.


Right Side Stretches

  1. stretchLie on your right side with your right leg bent at a 90-degree angle.
    1. Slightly bend your left knee and place it on a bolster, keeping your left leg behind your right.
    2. Straighten your right arm, keeping your trunk upright.
    3. Drop your right chest wall by slightly bending your right elbow.
    4. Reach forward with your left arm, keeping your arm at or slightly below the level of your shoulder.
    5. Press your left knee into the bolster, engaging your left inner thigh.
    6. Press your right knee down into the mat engaging your right outside hip (buttock).
    7. Keeping your left inner thigh and right outside hip engaged, inhale through your nose as you reach forward with your left hand.
    8. Exhale through your mouth and let your right chest sink further to the mat.
    9. Continue to push your left and right knees down toward the mat, and reach forward farther with your left hand as you inhale again.
    10. Exhale and let your right chest wall sink farther down.
    11. Inhale once more, reaching forward, and then exhale and let your right chest wall sink and open as much as possible.
    12. Relax and repeat four more times.


Lunge With Low Guard

  1. lungePlace your left knee on a 6-10 inch block, and your right leg in front of the block with your knee and hip bent and your foot flat.
  2. Round your back and reach forward placing your palms together and your arms below shoulder level.
  3. Maintaining contact with your right shoe arch, bring your left heel to the floor as you lift your knee off the block.
  4. While attempting to keep your left heel down, shift your body weight forward onto your right leg as you bring your left knee toward the block and maintain contact with your right shoe arch.
  5. Keeping your back rounded, rotate your trunk to the right by reaching to the right with both arms. You should feel the muscles on the front of your right thigh and right outside hip (buttock) engage.
  6. Hold this position while you take 4-5 deep breaths, in through your nose and out through your mouth.
  7.  Relax and repeat 4 more times.


Note: When performing with K-VEST, aim for 40 degrees of upper body sidebend and 50 degrees of rotation over a stable pelvis.

c_poulinChris Poulin is a certified athletic trainer and strength and conditioning specialist with over 20 years experience. He maintains certifications with the NSCA, PRI, NATA, NASM and TPI; he is also a member of the first class of certified athletic trainers to be recognized by the Postural Restoration Institute and earning the PRT credential. A co-owner of Sandhills Sports Performance in Southern Pines North Carolina, he specializes in athletic development and reconditioning.

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