ZenoLink Cycling 3D Animation

teaser of the the ZenoLink 3D cycling application.... will follow with animation, data overlay and power production information!

Soccer Kick KINETIC LINK 3D Animation

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
  

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:

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.

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.

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

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.

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.

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.

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. 

 

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.

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!

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.

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.

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.

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:

1. 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".
2. "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.
3. "Body Weight Exericses" are great and can be a useful part of a "complete" training regime.
4. 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.

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 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

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

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...

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

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.