Post by imperfectgolfer on Aug 3, 2015 12:40:47 GMT -5
In this thread, I am going to comment in detail on the RYKE effect/phenomenon.
The name "RYKE" comes from Kevin Ryan who obviously used selective parts of his personal name to create the name "RYKE".
Kevin Ryan presented his opinions on the RYKE effect in a 15 minute presentation at the World Science Congress of Golf in September 2014.
Here is the relevant 15 minute you-tube video that represents his official presentation.
I can readily agree that the RYKE effect may exist in skilled golfers who adopt a weak-neutral left hand grip, which necessitates the use of a PA#3 release action in the late downswing in order to square the clubface by impact. By contrast, I will show (in a future post) that it can play no role in golfers who adopt a very strong left hand grip because they do not use a PA#3 release action during their late downswing action.
Here is a link to Kevin Ryan's thread on the RYKE effect in the Jeffy-golf forum.
jeffygolf.com/showthread.php?1567-Golf-Physics-The-RYKEeffect%AE
In his introductory post, Kevin Ryan asserts the following-: "In this post I am introducing the RYKE effect® which is what I believe happens at release. It is a piece of physics that has not previously been understood or described, which I believe is fundamental to understanding why pros play a different game to most of us. You can help me to assess if the RYKE effect is what happens when you release during the golf swing."
What Kevin Ryan has introduced is a modification of the double pendulum swing model where he inserts a passive rotary joint at the lower end of the central arm.
The white cylindrical arm represents the central arm. The gold-colored cylinder is inserted in the peripheral end of the central arm and it allows the lower end of the central arm to passively swivel/rotate and that rotary motion causes the peripheral hinge joint (representing the left wrist) and peripheral arm (representing the club) to swivel around the central arm, which will result in a conical pendular motion of the peripheral arm (club).
What effect does that modification have on the behaviour of the double pendulum swing model?
See this you-tube video.
Here are capture images from the video, which demonstrate the RYKE effect.
In his video, KR demonstrates that an "impulsive torque" (due to a plastic rod striking a rigid metal pipe) can cause the double pendulum swing model to start to swivel counterclockwise due to a rotary motion happening at the level of the gold-colored insert and that this rotary motion causes the clubhead to follow a conical pendular path.
The capture images show a face-on (left image) and DTL view (right image) of the modified double pendulum swing model in action.
Image 1 is equivalent to the nearing-P6 position. The central arm has being moving along one-plane (equivalent to a skilled golfer's FLW motion between P4 and P6 that is parallel to the inclined plane) and the modified double pendulum device has retained its pre-set lag angle of 90 degrees.
Image 2 shows the peripheral arm passively releasing according to the law of the double pendulum (equivalent to the passive CF-release of PA#2 in a skilled golfer) and the peripheral arm is now located at the P6.2 position. Note that the peripheral arm (club) releases within the plane of the central arm (equivalent to the plane of motion of the lower left arm/FLW of the intact LAFW) and that is equivalent to what is seen in a skilled golfer (like Henrik Stenson) who has his intact LAFW traveling on (parallel to) the inclined plane between P6 and P6.2.
Image 3 shows the peripheral arm (club) at the P6.5 position. Note that the club (peripheral arm) is still releasing within the plane of motion of the central arm (intact LAFW) between P6.2 and P6.5 and it has now completely released (= equivalent to the completion of the release of PA#2). Remember that in a "real life" golfer (who uses a weak/neutral left hand grip), the endpoint of a PA#2 release occurs when the left wrist uncocks to a neutral position (and not to a fully uncocked position - which is the left wrist position where the left wrist is in maximum ulnar deviation) so the club should never end up being in a straight-line relationship with the left arm within the LAFW plane of left wrist radial => ulnar deviation at impact (when PA#2 is completely released). The angle between the left arm and club at impact within the plane of the intact LAFW (plane of left wrist radial => ulnar deviation) is called the accumulator #3 angle. I will later demonstrate that the magnitude of the accumulator #3 angle = 180 degrees - RYKE angle.
Note that he has a plastic rod attached to the hinge joint area so that it is angled at a ~90 degree angle relative to the plane of motion of the central arm, and that plastic rod is going to strike a copper-colored metal pipe at this exact time point and that physical strike will produce a counterclockwise rotary torque that will induce the RYKE effect ( = converting the peripheral arm's one-planar motion into a conical pendular motion) - by inducing a passive counterclockwise rotation of the gold-colored insert device (which can be deemed to be equivalent to a passive left forearm supinatory motion happening during a PA#3 release action that happens between P6.5 and impact).
Image 4 is at P7.5. Note that the peripheral arm (club) has continued its conical pendular motion due to continued passive rotation happening at the level of the gold-colored cylinder insert (= equivalent to a passive left forearm supinatory action happening post-impact between P7 and P7.5). Does this post-impact RYKE rotary phenomenon happen in a "real life" golf swing of a skilled golfer? I can readily imagine that it does if the golfer uses a roller type of non-DH hand release action (rather than a DH-hand release action) where the post-impact left forearm supinatory motion is passive, rather than active (as occurs in AJ Bonar's hand crossover hand release action).
In summary, Kevin Ryan's modification of the double pendulum swing model alters the behaviour of the DP swing model between P6.5 and impact and it has no effect prior to the "impulsive torque" force being applied at the ~P6.2 time point. Between P4 and P6.2, the modified DP swing model behaves exactly the same as a driven DP swing model. I think that this modified DP swing model could have significant applicability to a skilled golfer's downswing if he adopts a weak/neutral left hand grip, which necessitates the use of a PA#3 release action between P6.5 and P7 in order to ensure a square clubface by impact, and this modified-DP swing model suggests that any left forearm supination happening during a PA#3 release action could be passive and secondary to the RYKE phenomenon, and not secondary to an active contraction of the left forearm's supinator muscles.
Kevin Ryan never clearly states what biomechanical mechanism occurs in a "real life" golfer that is equivalent to his "impulsive torque". His modified-DP swing model merely infers that if an "impulsive torque" is applied in the late downswing (at ~P6.2 when the release of PA#2 is near-complete) that it will cause a passive left forearm supinatory motion, and I can agree that the RYKE effect may readily account for the PA#3 release action that is routinely seen in a skilled golfer's swing if he uses a weak/neutral left hand grip.
Let's now consider what frequently happens in skilled pro golfers who adopt a weak-neutral left hand grip.
Here is a graph from Phil Cheetham's PhD dissertation paper reflecting the changing pattern of handle twist velocity and left forearm supinatory motion during the downswing in pro golfers.
The vertical green line represents the start of the club release phenomenon (release of PA#2). Note that the handle does not twist (rotate) prior to the release of PA#2. Note that the handle starts to twist a little later in the downswing (starting at the twist release point) and the solid yellow phase represents the 1st phase of the club handle twist velocity graph where the handle twist velocity is low and where there is only a small amount of left forearm supinatory motion happening (see blue graph). That is followed by a 2nd phase where the handle twist velocity increases dramatically and that phase is associated with a sharp rise in the speed of left forearm supination (see blue graph after the vertical yellow arrow). The 2nd phase represents the release of PA#3 and it is very plausible that the rapid left forearm supinatory motion happening during this time period could be passively induced by the RYKE effect.
But why does phase 1 exist in a "real life" golf swing and could it be responsible for inducing the RYKE effect?
Consider a "real life" example of this two-phase left forearm supinatory motion - featuring Sergio Garcia's downswing action.
Capture images from a Sergio Garcia swing video.
Image 1 shows Sergio Garcia at the P5.5 position. Note that the butt end of his club points at the ball, which means that his club is on-plane (using Homer Kelley's definition of being "on-plane"). Note that the back of his GFLW/lower left forearm is parallel to the shallow inclined plane that his clubshaft is coming down between P4 and P5.5 (and it is equivalent to the elbow plane in image 1).
Images 2, 3 and 4 show what happens to his GFLW and club between P5.5 and P6 (image 4). Note that the back of his GFLW becomes progressively more vertical and that requires a left forearm supinatory motion. At P6, the back of his GFLW (left hand) is vertical and parallel to the ball-target line. This left forearm supinatory motion that happens between P5.5 and P6 represents phase 1 (as seen in Phil Cheetham's graph). What effect does this left forearm supinatory motion have on the club, which is starting to release? I think that it makes the club release in a more conical pendular manner so that the clubhead follows the conical pendular path seen in image 2 => image 3 => image 4, and that path is below the level of his right forearm and also underplane relative to the elbow plane. If Sergio Garcia kept his GFLW at the same angle seen in image 1 as his hands continued to moved downwards-and-forwards between P5.5 and P6, but released his club by the same amount, then the club release would occur on the elbow plane (rather than following a slightly underplane conical pendular path). Another significant biomechanical factor that affects the club's 3-D motion in space during this time period is the fact that his right forearm is moving from a condition of supination towards a more neutral position due to a right forearm pronatory motion happening between P5.5 and P6 and that causes his right palm, which was roughly at a 45 degree angle relative to the ground in image 1 (P5.5), to become vertically aligned by image 4 (P6). The right palm's 3-D motion works synergistically with the left palm's 3-D motion to ensure that the club follows that conical pendular path as it starts to release between P5.5 and P6. I strongly suspect that the combined "left forearm supinatory and right forearm pronatory" motion seen between P5.5 and P6 are active biomechanical motions, and I think that they are basically producing the biomechanical equivalent of the "impulsive torque" seen in Kelvin Ryan's modified-DP swing model, that will be capable of inducing the RYKE effect.
Consider what happens after P6.
Image 1 is at P6.2, image 2 is at P6.5 and image 3 is at impact. Note that club is undergoing a conical pendular motion as the left forearm continues to continuously supinate all the way until impact. The timing of the changing degree of left forearm supination (speed of left forearm supination) that is happening in the late dowswing can be best discerned by examining face-on images of the late downswing time period.
Image 1 is at P6.5. Note that club has nearly completed its PA#2 release action, but the back of his left hand/left lower forearm is still nearly parallel to the ball-target line.
Image 2 is at P6.7 and image 3 is at impact. Note how rapidly the back of the left hand is rotating counterclockwise between P6.7 and impact due to a left forearm supinatory motion, and this phenomenon (representing the PA#3 release action) is very similar in rotary pattern to the counterclockwise rotation of the peripheral arm (club) seen in Kevin Ryan's modified-DP swing model after the RYKE effect is induced by an "impulsive torque". There is one major potential difference between a "real life" golfer and Kevin Ryan's mechanical model and that difference relates to the role of the right arm/hand in causing, or at least synergistically promoting, a smooth PA#3 release action in the "real life" swing of a skilled golfer. Note how Sergio Garcia's right arm straightens between P6.5 and impact, and together with a small degree of right forearm pronation, it can potentially enable the right palm to apply a continuous push-pressure against PP#1 (located over the left thumb) in such a manner that it can cause, or synergistically assist, in the smooth/efficient release of PA#3. It is unknown to what degree Sergio Garcia's right forearm's paddlewheeling action between P6.5 and impact plays an important role in his PA#3 release action - relative to the potential role of a RYKE physical effect. I personally suspect that each golfer's personalised execution of human golf biomechanics is the major factor that determines the timing and exact pattern of the conical pendular motion that characterises the PA#3 release action needed to square the clubface by impact, and I suspect that the RYKE effect only plays a significant role in golfers who have a moderate-to-large RYKE angle by allowing the left forearm to passively rotate, thereby diminishing the amount of active left forearm supinatory muscular force needed to execute an efficient PA#3 release action.
In future posts, I will have much more to say about the RYKE effect. I personally think that many of Kevin Ryan's claims are irrational and scientifically unfounded, and I will explain why I harbor those personal opinions in future posts.
Jeff.
The name "RYKE" comes from Kevin Ryan who obviously used selective parts of his personal name to create the name "RYKE".
Kevin Ryan presented his opinions on the RYKE effect in a 15 minute presentation at the World Science Congress of Golf in September 2014.
Here is the relevant 15 minute you-tube video that represents his official presentation.
I can readily agree that the RYKE effect may exist in skilled golfers who adopt a weak-neutral left hand grip, which necessitates the use of a PA#3 release action in the late downswing in order to square the clubface by impact. By contrast, I will show (in a future post) that it can play no role in golfers who adopt a very strong left hand grip because they do not use a PA#3 release action during their late downswing action.
Here is a link to Kevin Ryan's thread on the RYKE effect in the Jeffy-golf forum.
jeffygolf.com/showthread.php?1567-Golf-Physics-The-RYKEeffect%AE
In his introductory post, Kevin Ryan asserts the following-: "In this post I am introducing the RYKE effect® which is what I believe happens at release. It is a piece of physics that has not previously been understood or described, which I believe is fundamental to understanding why pros play a different game to most of us. You can help me to assess if the RYKE effect is what happens when you release during the golf swing."
What Kevin Ryan has introduced is a modification of the double pendulum swing model where he inserts a passive rotary joint at the lower end of the central arm.
The white cylindrical arm represents the central arm. The gold-colored cylinder is inserted in the peripheral end of the central arm and it allows the lower end of the central arm to passively swivel/rotate and that rotary motion causes the peripheral hinge joint (representing the left wrist) and peripheral arm (representing the club) to swivel around the central arm, which will result in a conical pendular motion of the peripheral arm (club).
What effect does that modification have on the behaviour of the double pendulum swing model?
See this you-tube video.
Here are capture images from the video, which demonstrate the RYKE effect.
In his video, KR demonstrates that an "impulsive torque" (due to a plastic rod striking a rigid metal pipe) can cause the double pendulum swing model to start to swivel counterclockwise due to a rotary motion happening at the level of the gold-colored insert and that this rotary motion causes the clubhead to follow a conical pendular path.
The capture images show a face-on (left image) and DTL view (right image) of the modified double pendulum swing model in action.
Image 1 is equivalent to the nearing-P6 position. The central arm has being moving along one-plane (equivalent to a skilled golfer's FLW motion between P4 and P6 that is parallel to the inclined plane) and the modified double pendulum device has retained its pre-set lag angle of 90 degrees.
Image 2 shows the peripheral arm passively releasing according to the law of the double pendulum (equivalent to the passive CF-release of PA#2 in a skilled golfer) and the peripheral arm is now located at the P6.2 position. Note that the peripheral arm (club) releases within the plane of the central arm (equivalent to the plane of motion of the lower left arm/FLW of the intact LAFW) and that is equivalent to what is seen in a skilled golfer (like Henrik Stenson) who has his intact LAFW traveling on (parallel to) the inclined plane between P6 and P6.2.
Image 3 shows the peripheral arm (club) at the P6.5 position. Note that the club (peripheral arm) is still releasing within the plane of motion of the central arm (intact LAFW) between P6.2 and P6.5 and it has now completely released (= equivalent to the completion of the release of PA#2). Remember that in a "real life" golfer (who uses a weak/neutral left hand grip), the endpoint of a PA#2 release occurs when the left wrist uncocks to a neutral position (and not to a fully uncocked position - which is the left wrist position where the left wrist is in maximum ulnar deviation) so the club should never end up being in a straight-line relationship with the left arm within the LAFW plane of left wrist radial => ulnar deviation at impact (when PA#2 is completely released). The angle between the left arm and club at impact within the plane of the intact LAFW (plane of left wrist radial => ulnar deviation) is called the accumulator #3 angle. I will later demonstrate that the magnitude of the accumulator #3 angle = 180 degrees - RYKE angle.
Note that he has a plastic rod attached to the hinge joint area so that it is angled at a ~90 degree angle relative to the plane of motion of the central arm, and that plastic rod is going to strike a copper-colored metal pipe at this exact time point and that physical strike will produce a counterclockwise rotary torque that will induce the RYKE effect ( = converting the peripheral arm's one-planar motion into a conical pendular motion) - by inducing a passive counterclockwise rotation of the gold-colored insert device (which can be deemed to be equivalent to a passive left forearm supinatory motion happening during a PA#3 release action that happens between P6.5 and impact).
Image 4 is at P7.5. Note that the peripheral arm (club) has continued its conical pendular motion due to continued passive rotation happening at the level of the gold-colored cylinder insert (= equivalent to a passive left forearm supinatory action happening post-impact between P7 and P7.5). Does this post-impact RYKE rotary phenomenon happen in a "real life" golf swing of a skilled golfer? I can readily imagine that it does if the golfer uses a roller type of non-DH hand release action (rather than a DH-hand release action) where the post-impact left forearm supinatory motion is passive, rather than active (as occurs in AJ Bonar's hand crossover hand release action).
In summary, Kevin Ryan's modification of the double pendulum swing model alters the behaviour of the DP swing model between P6.5 and impact and it has no effect prior to the "impulsive torque" force being applied at the ~P6.2 time point. Between P4 and P6.2, the modified DP swing model behaves exactly the same as a driven DP swing model. I think that this modified DP swing model could have significant applicability to a skilled golfer's downswing if he adopts a weak/neutral left hand grip, which necessitates the use of a PA#3 release action between P6.5 and P7 in order to ensure a square clubface by impact, and this modified-DP swing model suggests that any left forearm supination happening during a PA#3 release action could be passive and secondary to the RYKE phenomenon, and not secondary to an active contraction of the left forearm's supinator muscles.
Kevin Ryan never clearly states what biomechanical mechanism occurs in a "real life" golfer that is equivalent to his "impulsive torque". His modified-DP swing model merely infers that if an "impulsive torque" is applied in the late downswing (at ~P6.2 when the release of PA#2 is near-complete) that it will cause a passive left forearm supinatory motion, and I can agree that the RYKE effect may readily account for the PA#3 release action that is routinely seen in a skilled golfer's swing if he uses a weak/neutral left hand grip.
Let's now consider what frequently happens in skilled pro golfers who adopt a weak-neutral left hand grip.
Here is a graph from Phil Cheetham's PhD dissertation paper reflecting the changing pattern of handle twist velocity and left forearm supinatory motion during the downswing in pro golfers.
The vertical green line represents the start of the club release phenomenon (release of PA#2). Note that the handle does not twist (rotate) prior to the release of PA#2. Note that the handle starts to twist a little later in the downswing (starting at the twist release point) and the solid yellow phase represents the 1st phase of the club handle twist velocity graph where the handle twist velocity is low and where there is only a small amount of left forearm supinatory motion happening (see blue graph). That is followed by a 2nd phase where the handle twist velocity increases dramatically and that phase is associated with a sharp rise in the speed of left forearm supination (see blue graph after the vertical yellow arrow). The 2nd phase represents the release of PA#3 and it is very plausible that the rapid left forearm supinatory motion happening during this time period could be passively induced by the RYKE effect.
But why does phase 1 exist in a "real life" golf swing and could it be responsible for inducing the RYKE effect?
Consider a "real life" example of this two-phase left forearm supinatory motion - featuring Sergio Garcia's downswing action.
Capture images from a Sergio Garcia swing video.
Image 1 shows Sergio Garcia at the P5.5 position. Note that the butt end of his club points at the ball, which means that his club is on-plane (using Homer Kelley's definition of being "on-plane"). Note that the back of his GFLW/lower left forearm is parallel to the shallow inclined plane that his clubshaft is coming down between P4 and P5.5 (and it is equivalent to the elbow plane in image 1).
Images 2, 3 and 4 show what happens to his GFLW and club between P5.5 and P6 (image 4). Note that the back of his GFLW becomes progressively more vertical and that requires a left forearm supinatory motion. At P6, the back of his GFLW (left hand) is vertical and parallel to the ball-target line. This left forearm supinatory motion that happens between P5.5 and P6 represents phase 1 (as seen in Phil Cheetham's graph). What effect does this left forearm supinatory motion have on the club, which is starting to release? I think that it makes the club release in a more conical pendular manner so that the clubhead follows the conical pendular path seen in image 2 => image 3 => image 4, and that path is below the level of his right forearm and also underplane relative to the elbow plane. If Sergio Garcia kept his GFLW at the same angle seen in image 1 as his hands continued to moved downwards-and-forwards between P5.5 and P6, but released his club by the same amount, then the club release would occur on the elbow plane (rather than following a slightly underplane conical pendular path). Another significant biomechanical factor that affects the club's 3-D motion in space during this time period is the fact that his right forearm is moving from a condition of supination towards a more neutral position due to a right forearm pronatory motion happening between P5.5 and P6 and that causes his right palm, which was roughly at a 45 degree angle relative to the ground in image 1 (P5.5), to become vertically aligned by image 4 (P6). The right palm's 3-D motion works synergistically with the left palm's 3-D motion to ensure that the club follows that conical pendular path as it starts to release between P5.5 and P6. I strongly suspect that the combined "left forearm supinatory and right forearm pronatory" motion seen between P5.5 and P6 are active biomechanical motions, and I think that they are basically producing the biomechanical equivalent of the "impulsive torque" seen in Kelvin Ryan's modified-DP swing model, that will be capable of inducing the RYKE effect.
Consider what happens after P6.
Image 1 is at P6.2, image 2 is at P6.5 and image 3 is at impact. Note that club is undergoing a conical pendular motion as the left forearm continues to continuously supinate all the way until impact. The timing of the changing degree of left forearm supination (speed of left forearm supination) that is happening in the late dowswing can be best discerned by examining face-on images of the late downswing time period.
Image 1 is at P6.5. Note that club has nearly completed its PA#2 release action, but the back of his left hand/left lower forearm is still nearly parallel to the ball-target line.
Image 2 is at P6.7 and image 3 is at impact. Note how rapidly the back of the left hand is rotating counterclockwise between P6.7 and impact due to a left forearm supinatory motion, and this phenomenon (representing the PA#3 release action) is very similar in rotary pattern to the counterclockwise rotation of the peripheral arm (club) seen in Kevin Ryan's modified-DP swing model after the RYKE effect is induced by an "impulsive torque". There is one major potential difference between a "real life" golfer and Kevin Ryan's mechanical model and that difference relates to the role of the right arm/hand in causing, or at least synergistically promoting, a smooth PA#3 release action in the "real life" swing of a skilled golfer. Note how Sergio Garcia's right arm straightens between P6.5 and impact, and together with a small degree of right forearm pronation, it can potentially enable the right palm to apply a continuous push-pressure against PP#1 (located over the left thumb) in such a manner that it can cause, or synergistically assist, in the smooth/efficient release of PA#3. It is unknown to what degree Sergio Garcia's right forearm's paddlewheeling action between P6.5 and impact plays an important role in his PA#3 release action - relative to the potential role of a RYKE physical effect. I personally suspect that each golfer's personalised execution of human golf biomechanics is the major factor that determines the timing and exact pattern of the conical pendular motion that characterises the PA#3 release action needed to square the clubface by impact, and I suspect that the RYKE effect only plays a significant role in golfers who have a moderate-to-large RYKE angle by allowing the left forearm to passively rotate, thereby diminishing the amount of active left forearm supinatory muscular force needed to execute an efficient PA#3 release action.
In future posts, I will have much more to say about the RYKE effect. I personally think that many of Kevin Ryan's claims are irrational and scientifically unfounded, and I will explain why I harbor those personal opinions in future posts.
Jeff.