Michael Finney
New
Here is an interesting statement he makes and I wondered what everyone thought about it:
Ideally the shoulders remain relatively stabile and relatively retracted at all times for the smoothest transfer of energy from the body to the clubhead and ultimately from the clubhead to the ball.
Here is the entire body of the text if you care to read. It was originally written as a response to a golf professional who had some questions for Mike Bentley. I took it from the Golf Teaching Professional Facebook page. Here you go:
I hope you have been well and your students are doing great. As you mentioned in the facebook group, muscles do undergo a stretch-shorten cycle in a golf swing, behaving just like a spring. The longest hitters have optimized stretch shorten cycles, mean...ing they have maximum magnitude of stretch and shorten, and time each component perfectly. Magnitude is certainly important, but magnitude combined with perfect timing produces the most force.
When the brain asks a muscle fiber, or multiple fibers to contract, movement around a joint is created. The speed and number of fibers recruited at an instant in time is what creates force. Elite athletes trump non-athletes in terms of how much force they are able to create in short periods of time, and this is reflected in the equation for power (work/time). Just think of Dustin Johnson or Jamie Sadlowski--lots of force created in a short period of time.
The timing of an efficient stretch-shorten cycle, at least in full swings, is a 3:1 ratio (backswing:downswing, or stretch:shorten). Optimally timing that cycle is the reason why long ball hitters on tour hit it so far, and amateurs do not. The timing sequence of amateurs is more like 3:2 or 4:1; the cause of which can be attributed to things such as joint or segmental immobility, instability, or faulty swing concepts.
When you said that you believed that an over-stretched muscle has less energy, you were spot on. Muscle fibers are connected to other muscle fibers like fishhooks. When a muscle fiber is overstretched or unplugged, micro tears are created and the muscle will shutoff, meaning it won’t contract. To picture an overstretched muscle, all one has to do is think of a yoga instructor—extremely mobile, but not able to create significant speed or power.
What we tend to do in the golf industry is focus only on the stretch component, the X-Factor. The common belief is that the bigger the stretch magnitude, the more force one is able to create. But that’s an incomplete statement. If the maximum stretch magnitude between pelvis and thorax created the most force, then a hyper mobile yoga instructor would outperform an athlete like Gary Woodland. It’s not just about the stretch. You need to look at the whole cycle: the stretch, the shorten, and the timing and magnitude of each. All of us focus on the differential, the magnitude, but forget about the timing of the stretch, or the timing of the muscular shortening.
Measuring Rotations
The timing of the SSC is essential to predicting power output, but the way people are currently measuring body rotations is inaccurate and is causing confusion. How one goes about measuring an object, especially a human body, can make a huge difference. The golf industry needs to do a more accurate job of measuring bodies so we can make substantive claims and truly see why the bombers on tour hit the ball so far. By more accurately measuring the body we can start to eliminate confusion and misinformation created by inaccurate claims.
We see numbers promoted in videos and articles that seem too high to be true, but since people believe that the stretch is all that matters, they look for numbers to support their theory. What’s misleading people, sports scientists and biomechanists included, is the current way of measuring the body.
The only way to accurately measure upperbody rotation, or any body rotation for that matter, would be to insert bone pins: a needle inserted into the bone, which is done on cadavers and live humans. In a perfect world, I’d insert bone pins at L4 and T4 to analyze pelvis vs. thorax rotation. Bone pins are by far the most accurate way to measure a body. Invasive bone pins are the gold standard for motion measurement because they can be placed directly on the segment that is moving. Bone pin placement on humans are infinitely more accurate than surface markers, which tend to slide easily.
In recent years, biomechanists have discovered that surface markers: electromagnetic, optical, or inertial sensors, lack validation for quantification of vertebral motion. The difference between a bone pin measurement and a surface marker can vary as much as 8 Degrees. During a gait analysis study at the University of Kentucky, errors of 7° occurred while the patient was walking, let alone trying to make a golf swing. Add up a few degrees here and there of each of the 33 spinal vertebrae and you can easily get some crazy data. Surface markers are more practical, they don’t inflict pain or create infections, but they aren’t as accurate. A human’s skin and the garments we wear vary greatly from individual to individual, and are prone to inaccurate measurements. We must measure as accurately as possible to make substantive claims to avoid misleading the general public.
Shoulder Turn
While shoulder turn has always been the guiding metric for X-Factor, it perhaps is more accurate and interesting to know a golfer’s thoracic spine rotation. In an efficient golf swing, shoulder joints remain as perpendicular as possible to the thorax throughout the entire swing. They should not fluctuate much in terms of protraction, retraction, elevation and rotation. Ideally the shoulders remain relatively stabile and relatively retracted at all times for the smoothest transfer of energy from the body to the clubhead and ultimately from the clubhead to the ball.
However, most golfers don’t fit that ideal and often come out of their posture, making compensatory moves in their shoulder complex in an effort to create more power, get a bigger X-Factor, or avoid physical restrictions.
The compensatory moves: protraction, retraction, elevation, and depression, all can occur virtually independent of the thoracic spine. The clavicle (collar bone), can elevate 45°, depress 15°, retract 15°, protract 15°, or rotate 30-55°, without any thoracic spine rotation at all. Stand against a wall and try these movements yourself to experience why measuring the shoulder joints might not be the best thing to do. It is very easy to create a 15° shoulder turn (by protracting your right shoulder for example) without moving your thoracic spine at all.
In a golf swing, the trunk or thoracic spine rotates in response to pelvis rotation (which is created by shifts in ground force vectors). Measuring thoracic spine rotation in reference to the pelvis is the most efficient way to look at upper body rotational power, mobility and stability.
Hope that helps and keep the passion!
-Mike
Ideally the shoulders remain relatively stabile and relatively retracted at all times for the smoothest transfer of energy from the body to the clubhead and ultimately from the clubhead to the ball.
Here is the entire body of the text if you care to read. It was originally written as a response to a golf professional who had some questions for Mike Bentley. I took it from the Golf Teaching Professional Facebook page. Here you go:
I hope you have been well and your students are doing great. As you mentioned in the facebook group, muscles do undergo a stretch-shorten cycle in a golf swing, behaving just like a spring. The longest hitters have optimized stretch shorten cycles, mean...ing they have maximum magnitude of stretch and shorten, and time each component perfectly. Magnitude is certainly important, but magnitude combined with perfect timing produces the most force.
When the brain asks a muscle fiber, or multiple fibers to contract, movement around a joint is created. The speed and number of fibers recruited at an instant in time is what creates force. Elite athletes trump non-athletes in terms of how much force they are able to create in short periods of time, and this is reflected in the equation for power (work/time). Just think of Dustin Johnson or Jamie Sadlowski--lots of force created in a short period of time.
The timing of an efficient stretch-shorten cycle, at least in full swings, is a 3:1 ratio (backswing:downswing, or stretch:shorten). Optimally timing that cycle is the reason why long ball hitters on tour hit it so far, and amateurs do not. The timing sequence of amateurs is more like 3:2 or 4:1; the cause of which can be attributed to things such as joint or segmental immobility, instability, or faulty swing concepts.
When you said that you believed that an over-stretched muscle has less energy, you were spot on. Muscle fibers are connected to other muscle fibers like fishhooks. When a muscle fiber is overstretched or unplugged, micro tears are created and the muscle will shutoff, meaning it won’t contract. To picture an overstretched muscle, all one has to do is think of a yoga instructor—extremely mobile, but not able to create significant speed or power.
What we tend to do in the golf industry is focus only on the stretch component, the X-Factor. The common belief is that the bigger the stretch magnitude, the more force one is able to create. But that’s an incomplete statement. If the maximum stretch magnitude between pelvis and thorax created the most force, then a hyper mobile yoga instructor would outperform an athlete like Gary Woodland. It’s not just about the stretch. You need to look at the whole cycle: the stretch, the shorten, and the timing and magnitude of each. All of us focus on the differential, the magnitude, but forget about the timing of the stretch, or the timing of the muscular shortening.
Measuring Rotations
The timing of the SSC is essential to predicting power output, but the way people are currently measuring body rotations is inaccurate and is causing confusion. How one goes about measuring an object, especially a human body, can make a huge difference. The golf industry needs to do a more accurate job of measuring bodies so we can make substantive claims and truly see why the bombers on tour hit the ball so far. By more accurately measuring the body we can start to eliminate confusion and misinformation created by inaccurate claims.
We see numbers promoted in videos and articles that seem too high to be true, but since people believe that the stretch is all that matters, they look for numbers to support their theory. What’s misleading people, sports scientists and biomechanists included, is the current way of measuring the body.
The only way to accurately measure upperbody rotation, or any body rotation for that matter, would be to insert bone pins: a needle inserted into the bone, which is done on cadavers and live humans. In a perfect world, I’d insert bone pins at L4 and T4 to analyze pelvis vs. thorax rotation. Bone pins are by far the most accurate way to measure a body. Invasive bone pins are the gold standard for motion measurement because they can be placed directly on the segment that is moving. Bone pin placement on humans are infinitely more accurate than surface markers, which tend to slide easily.
In recent years, biomechanists have discovered that surface markers: electromagnetic, optical, or inertial sensors, lack validation for quantification of vertebral motion. The difference between a bone pin measurement and a surface marker can vary as much as 8 Degrees. During a gait analysis study at the University of Kentucky, errors of 7° occurred while the patient was walking, let alone trying to make a golf swing. Add up a few degrees here and there of each of the 33 spinal vertebrae and you can easily get some crazy data. Surface markers are more practical, they don’t inflict pain or create infections, but they aren’t as accurate. A human’s skin and the garments we wear vary greatly from individual to individual, and are prone to inaccurate measurements. We must measure as accurately as possible to make substantive claims to avoid misleading the general public.
Shoulder Turn
While shoulder turn has always been the guiding metric for X-Factor, it perhaps is more accurate and interesting to know a golfer’s thoracic spine rotation. In an efficient golf swing, shoulder joints remain as perpendicular as possible to the thorax throughout the entire swing. They should not fluctuate much in terms of protraction, retraction, elevation and rotation. Ideally the shoulders remain relatively stabile and relatively retracted at all times for the smoothest transfer of energy from the body to the clubhead and ultimately from the clubhead to the ball.
However, most golfers don’t fit that ideal and often come out of their posture, making compensatory moves in their shoulder complex in an effort to create more power, get a bigger X-Factor, or avoid physical restrictions.
The compensatory moves: protraction, retraction, elevation, and depression, all can occur virtually independent of the thoracic spine. The clavicle (collar bone), can elevate 45°, depress 15°, retract 15°, protract 15°, or rotate 30-55°, without any thoracic spine rotation at all. Stand against a wall and try these movements yourself to experience why measuring the shoulder joints might not be the best thing to do. It is very easy to create a 15° shoulder turn (by protracting your right shoulder for example) without moving your thoracic spine at all.
In a golf swing, the trunk or thoracic spine rotates in response to pelvis rotation (which is created by shifts in ground force vectors). Measuring thoracic spine rotation in reference to the pelvis is the most efficient way to look at upper body rotational power, mobility and stability.
Hope that helps and keep the passion!
-Mike
