teaser of the the ZenoLink 3D cycling application.... will follow with animation, data overlay and power production information!
a collection of thoughts, comments, research, opinion, and commentary on biomechanics, motion analysis, sports performance, movement patterns, neuromechanics, sports training, performance enhancement
Thursday, May 16, 2013
Tuesday, May 14, 2013
Bryce Harper Swing Analysis - Lower Body Power
what we can learn from inaccuracies in the Bryce Harper Swing article, Washington Post
when analysis of mechanics drivers or biomechanics is based on aesthetics it tends to focus on obvious external events, unfortunately the obvious external events very rarely coincide with important driving mechanism - the key elements of power and movement are things that we can't "see" and usually happen well before the visual event we are focused on
the good thing is that we can "measure" these key events using 3D motion capture and other tools including force plates and EMG
when analysis of mechanics drivers or biomechanics is based on aesthetics it tends to focus on obvious external events, unfortunately the obvious external events very rarely coincide with important driving mechanism - the key elements of power and movement are things that we can't "see" and usually happen well before the visual event we are focused on
the good thing is that we can "measure" these key events using 3D motion capture and other tools including force plates and EMG
Wednesday, May 8, 2013
ZenoLink Soccer Kick Kinetic Link
Soccer kick kinetic link from an elite male collegiate player.
Sequence: Pelvis rotates rapidly in a counter clockwise direction, just
after plant leg contact with ground. Pelvis then quickly decelerates
as the kick leg hip rapidly flexes, resulting in knee flexion, loading
the quad (stretch-shorten, active eccentric load). Just before the foot
strikes the ball, hip flexion decelerates, facilitating a ballistic
knee extension of the kick leg.
3D animation of the soccer kick kinetic link:
Tuesday, May 7, 2013
ZenoLink Basketball Pound / Ball Handling Analysis
#ZenoLink Basketball Pound Animation
Pound dribbling drill to measure power and ball speed retention. Acceleration is key to creating the highest ball speed retention on rebound back to the hand. The faster the ball gets back to the hand the less time in the air and the more time the player has control of it, minimizing the ability for a defender to steal it and also maximizing control over movement and direction.
Better acceleration of the ball is a result of better dribble arm, elbow extension acceleration, which in turn is a result of core and lower body stability and power/speed transfer. The better the ball accelerates the better is reaches highest speed closer to the ground which in turn results in better rebound and return speed.
Pound dribbling drill to measure power and ball speed retention. Acceleration is key to creating the highest ball speed retention on rebound back to the hand. The faster the ball gets back to the hand the less time in the air and the more time the player has control of it, minimizing the ability for a defender to steal it and also maximizing control over movement and direction.
Better acceleration of the ball is a result of better dribble arm, elbow extension acceleration, which in turn is a result of core and lower body stability and power/speed transfer. The better the ball accelerates the better is reaches highest speed closer to the ground which in turn results in better rebound and return speed.
Wednesday, April 3, 2013
So you want to throw hard?!
Baseball pitch velocity has become a big topic of discussion these days, with the number of pitcher able to reach or exceed the 100mph mark increasing and the average pitch velocity now creeping into the 90's (where it had been high 80's).
Pitch velocity is a product of arm speed. Arm speed is a result of the coordination of elbow extension and shoulder internal rotation velocity. When coordination is optimal, shoulder internal rotation speeds can reach anywhere from 6000 deg/sec to upwards of 8000 deg/sec at ball release.
Pitch velocity is a product of arm speed. Arm speed is a result of the coordination of elbow extension and shoulder internal rotation velocity. When coordination is optimal, shoulder internal rotation speeds can reach anywhere from 6000 deg/sec to upwards of 8000 deg/sec at ball release.
Friday, March 29, 2013
GO FAST - base stealing
How fast do you think you are? How fast could you be?
3D animation and high level biomechanical performance/injury analysis
of sprint-acceleration-base stealing, captured on the field, or in the
gym, during spring training, as part of combine testing... NO sensors,
NO wires, NO markers, JUST DATA!
#unlockyourpotential #gofast #ZenoLink
Tuesday, March 26, 2013
Hockey Acceleration - PULL (hip-knee flexion)
"PULL" is Yin to "PUSH" 's Yang. Most who analyze acceleration focus on extension or "push" ... however, flexion or "pull" is equally as important AND is most often the biggest difference between good acceleration vs. poor acceleration.
What is most important about "pull" or flexion is the timing with which it is initiated, not the magnitude. Unlike "push" or extension where the hip and knee reach peak force/speed simulatneously, "pull" or flexion is initiated by the knee and followed by the hip. The initiation of knee flexion should occur while the stance foot is still in contact with the ground - this is of utmost importance.
If knee flexion occurs late or after the stance leg has lost contact with the ground, it disrupts the pull pattern and degrades forward acceleration.
What is most important about "pull" or flexion is the timing with which it is initiated, not the magnitude. Unlike "push" or extension where the hip and knee reach peak force/speed simulatneously, "pull" or flexion is initiated by the knee and followed by the hip. The initiation of knee flexion should occur while the stance foot is still in contact with the ground - this is of utmost importance.
If knee flexion occurs late or after the stance leg has lost contact with the ground, it disrupts the pull pattern and degrades forward acceleration.
Saturday, March 23, 2013
Golf PST - basic Core Separation exercise
One of the most basic, but most important foundational movement patterns - core differentiation/dissociation. It develops the ability to grip the ground, creating a solid foot-ground interface which in turn facilitates the ability to differentiate between the pelvis and the upper thoracic.
Friday, March 22, 2013
Hockey Acceleration - PUSH (hip-knee extension)
To accelerate effectively a skater must PUSH against the ice with each leg. This PUSH is accomplished through a rapid hip and knee extension - occurring in the leg in contact with the ice. The peak extension speed of the hip and knee should be reached simultaneously to apply the greatest amount of vertical and horizontal force. Peak joint angular speed/force application should occur in the stance phase generation about half way between mid-stance and toe-off to be most effective in creating acceleration.
Thursday, March 21, 2013
Hockey Skate Acceleration - ZenoLink 2.0 3D Animation
ZenoLink takes high-speed 2D video of a skater accelerating from a dead-stop and renders a very accurate 6dof 3D representation. Analysis can be done on the biomechanics of performance and injury, distilling highly technical data down into very usable information. Performance issues can be assessed and a specialized treatment/training plan can be created for the athlete.
Tuesday, March 19, 2013
Is it Functional or just Fancy?!
An exercise/training program is not "functional" unless the physical attributes gained are effectively applied to activity specific performance.
This is an extremely important concept to grasp if you are training to improve your performance in a specific athlete activity.
Just because an "exercise" is deemed "functional" in the gym does not mean its functional with respect to the actual activity you are using it to train for...
Very often an exercise is labeled as functional because its "multi-planar", "multi-joint" and neuromechanically fairly complex... but that doesn't guarantee that it will have any substantially positive impact on the activity you are training for, ie. baseball swing, tennis serve. Just as often a gym exercise is created that "looks like" the actual activity, but the reality is that the movement patterns are not that of the activity and really have no direct bearing on the activity - even worse many times create ineffective patterns relative to those needed to perform the activity.
In the same vein, a simple exercise may actually create physical attribute (ie. strength, mobility, power) that is directly and effectively transferable to the sport specific activity is used to train for...
The moral of the story is just because its "fancy" doesn't mean its functional or the attributes transferable. Understand the primary drivers behind the sport specific activity and train to enhance the components used to perform those drivers. Now THAT'S functional.
This is an extremely important concept to grasp if you are training to improve your performance in a specific athlete activity.
Just because an "exercise" is deemed "functional" in the gym does not mean its functional with respect to the actual activity you are using it to train for...
Very often an exercise is labeled as functional because its "multi-planar", "multi-joint" and neuromechanically fairly complex... but that doesn't guarantee that it will have any substantially positive impact on the activity you are training for, ie. baseball swing, tennis serve. Just as often a gym exercise is created that "looks like" the actual activity, but the reality is that the movement patterns are not that of the activity and really have no direct bearing on the activity - even worse many times create ineffective patterns relative to those needed to perform the activity.
In the same vein, a simple exercise may actually create physical attribute (ie. strength, mobility, power) that is directly and effectively transferable to the sport specific activity is used to train for...
The moral of the story is just because its "fancy" doesn't mean its functional or the attributes transferable. Understand the primary drivers behind the sport specific activity and train to enhance the components used to perform those drivers. Now THAT'S functional.
Friday, March 15, 2013
ZenoLink 2.0 Base Stealing 3D Animation
ZenoLink 2.0 ... 3D animation sync'd with actual high speed video for base stealing. No wires, No sensors, No laboratory - just 6dof 3D data!
Thursday, March 14, 2013
Dynamic Golf Backswing PST
Setup, take-away and backswing should be as dynamic as your transition and downswing... here is a basic progression of backswing PST that will train athleticism into your setup, takeaway and backswing... AND will help you transition your exercise/PST athleticism into your golf swing and ball striking.
Acceleration 101
In most sports acceleration or quickness is more important than top end "speed". Acceleration defined as the ability to create speed from a dead stop or change of direction.
The three keys to acceleration are push, pull and core.
The three keys to acceleration are push, pull and core.
Monday, March 11, 2013
Use your upper body to train your lower body
...sometimes the most effective way to train the lower body, is to focus on the upper body... when the upper body moves the lower body has to interact with the ground to facilitate the movement - so the quicker, more ballistic and/or faster the upper moves the quicker, more ballistic and/or faster the lower body needs to produce the corresponding ground reaction force.
Friday, March 1, 2013
Are my eyes deceiving me?!
A real short video, explaining what we see doesn't always match what is actually happening biomechanically... using a photo still sequence, I explain what is occurring as a function of ground reaction forces and relationship between center of pressure and center of mass. It is important to understand the underlying mechanisms that drive movement and ultimately what we "SEE" to better evaluate performance and train more effective patterns.
Thursday, February 28, 2013
Response to a MJ Body Weight Exercise article
The other day, I posted how much I hated an Men's Journal article about using body weight exercises... I received a bunch of replies regarding my comments, so thought I would create a video response to clarify what my issues are with the article.
Summary:
Summary:
- The article was written as a "hype" piece with ridiculous statements about the benefits of "body weight exercises" and the downfalls, even the dangers of "weighted exercises".
- "Body Weight Exericses" are just exercises that use your body weight as resistance or load rather than some other form of weight... a body weight squat is NO different from a barbell squat except for the resistance or load.
- "Body Weight Exericses" are great and can be a useful part of a "complete" training regime.
- DON'T BELIEVE THE HYPE!!! ... in other words, do your research and be an educated consumer... a magazine's primary goal is selling advertisement space, second is selling magazines, last is credible information.... keep in mind good information is BORING.
Tuesday, February 26, 2013
Arms trapped - visual swing fault
A very common "visual" swing fault is the arms being stuck to the body
or pinned to the torso and not properly releasing into impact. This video explores the cause of the issue on a biomechanics or
sequence/coordination level and how to approach resolving the swing
fault.
The swing fault is almost always mis-diagnosed as the body moving too fast for the arms as a result the remedy revolves around the body - hips/torso being too fast and the arms being too slow.
In fact the issue is almost always the arms being too fast or too quick to accelerate. The arms initiate the downswing rather than the lower body and disrupt the kinetic link sequence. The torso then accelerates late in the swing, out of sequence, giving the appearance of the arms being trapped behind the body.
The swing fault is almost always mis-diagnosed as the body moving too fast for the arms as a result the remedy revolves around the body - hips/torso being too fast and the arms being too slow.
In fact the issue is almost always the arms being too fast or too quick to accelerate. The arms initiate the downswing rather than the lower body and disrupt the kinetic link sequence. The torso then accelerates late in the swing, out of sequence, giving the appearance of the arms being trapped behind the body.
Monday, February 25, 2013
The ZenoLink 3D "speed trap"
An explanation of how ZenoLink uses video to create a 3D representation of bodies or objects in space and from that data calculate SPEED ! resultant speed as well as the direction of applied speed
some related links
Velocity
Derivative
Direct Linear Transformation (DLT)
DLT Method
some related links
Velocity
Derivative
Direct Linear Transformation (DLT)
DLT Method
Tuesday, February 19, 2013
Ground Reaction Forces Applied for Golf Swing - Center Of Pressure
This video is an overview description of pressure and center of pressure measurements in the golf swing, followed by an explanation of entry level training of foot to ground interaction in the golf swing:
Center of Pressure between the two feet is influenced by not only the amount of force applied through the foot into the ground by to a large extent the direction of the applied force. Keeping a good foot-ground interface through out back swing, transition and down swing is important for creating good force and a good pattern of force application.
some related research:
Pressure - Wikipedia
Center of Pressure - Wikipedia
Plantar Center of Pressure and it’s Effect on Golf Swing Distance and Accuracy
An Analysis Of The Kinetics And Kinematics Of The Golf Swing
Biomechanics of shoe-ground interaction in golf
Center of Pressure between the two feet is influenced by not only the amount of force applied through the foot into the ground by to a large extent the direction of the applied force. Keeping a good foot-ground interface through out back swing, transition and down swing is important for creating good force and a good pattern of force application.
some related research:
Pressure - Wikipedia
Center of Pressure - Wikipedia
Plantar Center of Pressure and it’s Effect on Golf Swing Distance and Accuracy
An Analysis Of The Kinetics And Kinematics Of The Golf Swing
Biomechanics of shoe-ground interaction in golf
Monday, February 18, 2013
Are back-off sets useful after a strength workout?
great research summary on using a "back-off set" after a strength workout
Are back-off sets useful after a strength workout?
"The researchers concluded that the combined 4-week training program led to a larger increase in 1RM leg press than the simple 4-week strength program followed by the normal group. The only difference between the two programs was the addition of a single set at 50% of 1RM after the main sets."
"What are the practical implications? For strength and power athletes: Adding a back-off set at 50% of 1RM following a workout involving a strength protocol at high percentages of 1RM (e.g. 85 – 90%) may increase strength and size gains without compromising gains in power."
... I will definitely be adding a back-off set to see if it impacts my strength building protocols...
Are back-off sets useful after a strength workout?
"The researchers concluded that the combined 4-week training program led to a larger increase in 1RM leg press than the simple 4-week strength program followed by the normal group. The only difference between the two programs was the addition of a single set at 50% of 1RM after the main sets."
"What are the practical implications? For strength and power athletes: Adding a back-off set at 50% of 1RM following a workout involving a strength protocol at high percentages of 1RM (e.g. 85 – 90%) may increase strength and size gains without compromising gains in power."
... I will definitely be adding a back-off set to see if it impacts my strength building protocols...
ground reaction forces in golf: a response
if you try to create a rotational movement like a med ball pass standing on a slippery surface, why do your feet move in the opposite direction of the intended rotation??
you use ground reaction force to produce a force-couple/torque which is translated from the feet-ground through the legs to the pelvis to initiate the rotational motion which in turn produces the subsequent coordination to toss the med ball
ground reaction force is the force that is equal and OPPOSITE of the force applied by you into the ground through your feet
when you stand on "sliders" you aren't able to create friction, so the ground is not able to "push back" ... the legs twist in the direction you are applying force
this video/response is in response to a nice video post last week by James Hong to Michael Beaumont regarding the lower body action or mechanism in the golf swing
Some papers on the topic... use the references in each paper as additional resources and/or pubmed or google educational searches on ground reaction forces in swing patterns or in sport biomechanics - also try to google "cavanagh ground reaction forces":
Lower Body Mechanics During the Baseball Swing
Ground Reaction Forces and Torques of Professional and Amateur Golfers
A comparison of golf shoe designs highlights greater ground reaction forces with shorter irons
Messier, 1985
Williams and Cavanagh, 1983
you use ground reaction force to produce a force-couple/torque which is translated from the feet-ground through the legs to the pelvis to initiate the rotational motion which in turn produces the subsequent coordination to toss the med ball
ground reaction force is the force that is equal and OPPOSITE of the force applied by you into the ground through your feet
when you stand on "sliders" you aren't able to create friction, so the ground is not able to "push back" ... the legs twist in the direction you are applying force
this video/response is in response to a nice video post last week by James Hong to Michael Beaumont regarding the lower body action or mechanism in the golf swing
Some papers on the topic... use the references in each paper as additional resources and/or pubmed or google educational searches on ground reaction forces in swing patterns or in sport biomechanics - also try to google "cavanagh ground reaction forces":
Lower Body Mechanics During the Baseball Swing
Ground Reaction Forces and Torques of Professional and Amateur Golfers
A comparison of golf shoe designs highlights greater ground reaction forces with shorter irons
Messier, 1985
Williams and Cavanagh, 1983
Friday, February 15, 2013
a starting point
If you are going to discuss biomechanics you should have some basic idea of the terms, concepts, definitions, units of measurement, principles, etc.
This is a good reference... not the only one, but a good start:
Glossary of Biomechanical Terms, Concepts, and Units
Mary M Rodgers and Peter R Cavanagh
PHYS THER. 1984; 64:1886-1902.
This is a good reference... not the only one, but a good start:
Glossary of Biomechanical Terms, Concepts, and Units
Mary M Rodgers and Peter R Cavanagh
PHYS THER. 1984; 64:1886-1902.
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