By Nunzio Signore (BA, CSCS, CPT, NASM, FMS) and Bahram Shirazi (BSEE, MBA)
Until not long ago sports-related motion capture systems (mocap) were primarily available in research labs, rehab facilities or biomechanics departments at universities. Historically, much of the work in this arena has been performed by biomechanists who specialize in the study of movement in biological systems, including human beings. They generally use the principles of physical mechanics combined with biology to understand:
- How biological systems move
- How they can move more effectively and efficiently
- Why they sometimes get injured and how to reduce the incidence of injury
Two prominent figures in the world of baseball mocap have been Dr. Glenn Fleisig and Dr. James Andrews, dating back to 1985 with their work at the American Sports Medicine Institute (“ASMI”).
But times are changing fast…
More recently a handful of commercial training facilities, including ourselves (working with Qualisys), have also installed mocap systems. They provide an enormous amount of information which can be collected during an assessment. However, the value of the information, like every other piece of tech we own, is not in the numbers we collect in the assessment, but what we do with the information… the FIXES!
To put it simply…
“Installing a Qualisys mocap system into a commercial facility like RPP is like throwing gas on a fire…”
Let’s review each of these 2 components:
- The Assessment
- The Fixes
Historically, here at RPP, we have assessed our pitchers and players via a movement screen and a strength and power testing protocol. It’s a 1-hour examination of the body and is used to assess an athlete’s movement strategies, current strength levels as well as their ability to be explosive. Most people who have observed our assessment believe it’s about as good as you can get. In addition, we also always perform a detailed video review via a 4-camera system to get a good idea of how this athlete moves down the mound or behind the plate.
Combining video analysis with the assessment gives us a fairly good picture of the athlete’s physical profile and what we may need to do from a strength or mobility standpoint to help any mechanical disconnects. This can help us solve timing issues that can play a main role in:
- Creating a higher velocity ceiling
- Reduce the risk of injuries resulting from repetitive stress
- Help an athlete who may be in a slump
However, as thorough as our assessments are, they are also static and 2-dimensional in nature. We’re basically testing a car in idle. A mocap system allows you to check the same car at 90 mph. There is a significant difference. Simply put, a static assessment can provide a very comprehensive picture, but there are gaps in the information. And in a movement pattern that takes 1.5 seconds, the mocap system allows us to fill most of these gaps.
A motion capture system simply collects tons of data. Depending on the speed at which it operates it could total 100,000 data points or more in 1-2 seconds. The information is varied and extensive. However, prior work by Drs. Andrews and Fleisig at ASMI and Driveline Baseball as well as our own collaboration with the Wake Forest Pitching Lab has made our work substantially easier.
Parsing through the different parts of a delivery, you can effectively reduce the relevant data points to a more manageable data set. The following is a very brief snapshot of what we consider to be some of the relevant metrics calculated during a mocap evaluation:
- Elbow Extension Velocity
- Shoulder Horizontal Abduction
- Torso Angular Velocity
- Shoulder Abduction (from Foot Plant to Ball Release)
- Hip-Shoulder Separation Timing
- Front Knee Angular Velocity
- Peak Pelvis to Peak Torso Timing
These include where certain body parts are in relation to each other and more importantly WHEN they are engaged during the delivery. Being able to mark specific points in the delivery on the kinematic sequence (see below) with pinpoint accuracy is key and it’s one of the main reasons that mocap is more accurate than trying to slow down 2-D video.
At first glance, even with a reduced dataset, it can be information-overload. But as you get more comfortable with the voluminous amount of info, the data begins to tell you things.
Comparing this information to what we had access to previously, there are many important metrics specifically timing and angular velocity issues that you can’t see with the same amount of accuracy with a static assessment or 2D video analysis. Here are a few examples and a brief summary of their relevance:
- Kinematic Sequence – This graph (above) tells us much about how efficiently an athlete is generating and transferring speed throughout the body. Through proper deceleration, the athlete will be able to transfer force more efficiently into the arm and/or bat.
- Shoulder Horizontal Abduction (Scap Load) – Performing a good scap load helps resist early trunk rotation while maintaining a good trunk stack into foot plant. It also helps resist more provocative lever arms at the shoulder/elbow.
- Hip Rotation Timing – Precise timing of hip rotation will help put the lead leg in the most optimal position to block / decelerate and create an anterior pelvic tilt to set up the angle the spine will eventually flex to.
- Peak Pelvis to Peak Torso Timing – While much importance seems to be placed on the amount of hip-shoulder separation, it’s actually WHEN this happens (preferably at FP or even slightly after) that is more telling in regard to velocity. We want to create enough separation to maximize what we’re doing with the amount of hip-shoulder separation we have created. This desired metric of .035-.70ms, is lightning fast and only able to be displayed on a mocap report.
- Knee Angular Velocity – This metric has one of the highest correlations to throwing velo as well as exit velocity. Much like hip-shoulder separation the amount, while important, is not as crucial as the SPEED at which extension is happening.
The value of the information, like every other piece of tech we own, is not in the numbers, but what do with the information… the FIXES.
Here is one example of a pelvic timing issue due to a poor decel pattern that we couldn’t previously evaluate with our static assessment and 2-D video analysis alone:
After a brief conversation with Randy Sullivan at the Florida Baseball Ranch, we worked on a better co-contraction of the front leg in the weight room to help improve his decel on the front leg.
(Lunge w/ Pulse)
(Lunge w/ Stick)
We then took the drill and progressed it to the mound. By utilizing the Core Velocity Belt we worked on adding an under and over-speed training element to help improve hip rotation timing and speeds.
(CVB Load Drill)
(CVB Over-Speed Drill)
Below is a comparison of 2 mocap reports 1-month apart, pre- and post-drill / throwing work. Getting this athlete, a better decel pattern combined with the work with the CVB improved all metrics, including better pelvis speeds as well as reaching those peak speeds later and closer to max ER. The timing differential between the pelvis and torso improved as a result as well. While there is still work to be done, this athlete is making great gains in a short period of time improving metrics that may have “gotten by” the naked eye using 2-D video alone.
Over time you can begin to map out which mechanical issues have the highest correlation with other metrics in the report, from drops in velocity to a pitcher’s ability to throw certain types of pitches. For example, as mentioned before, we know from over 400 data points that knee angular velocity has a high correlation with throwing velocity.
While there is no replacement for great coaching, implementing a mocap system for helping athletes requires several different disciplines. You need a biomechanist, a strength coach with extensive knowledge in the specific movements of the sport (like pitching / hitting) and a baseball coach who has the experience and understanding of the actual craft of pitching / hitting. It really takes a group of talented individuals much like a pit crew in racing with extensive knowledge in their fields to bring this all together. It also helps if all 3 participants have some knowledge and understanding of the other’s field of expertise.
Please keep in mind that these numbers come from particular motion capture systems. In theory, all optical systems and all electromagnetic systems should find the same numbers. However, the world is not perfect, so you need to be cautious in comparing measurements from your system with data collected in different ways. It’s always best to eventually create your own data base.
Although, it hasn’t been long, it’s already easy to see why the addition of mocap into our assessments will help us reap huge benefits for our athletes.
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