A breakdown of what biomechanics really is and how we use it within our evaluations

For years now, athletes, parents, and coaches alike have inquired about our pitching evaluation with a popular question always being “so what exactly is biomechanics, anyways?”. A quick web browser search gives us the definition as “the study of the mechanical laws relating to the movement or structure of living organisms”, or as I often explain it, essentially just coupling anatomy & physiology with physics. Examining how the body moves allows us to understand how we create force to accomplish a task, like pitching, and how forces are applied back to the body as a result of those movements.

We often see the most elite pitchers are capable of moving their bodies in a whip-like fashion, moving faster and faster as they approach ball release. This summation of speed causes body segments further from our spine to rotate faster and faster, thus imparting more force on the baseball as we release it (and thus, faster throwing velocities). Sequential movements performed correctly throughout the body act like smooth baton handoffs in a relay race while faulty throwing mechanics act as baton fumbles. Ideally, we want to maximize the number of successful baton handoffs made within the body to maximize an athlete’s potential to throw their hardest. What makes the UNO Pitching Lab unique is that we can quantify how well pitchers can transfer energy through the use of a research-grade motion capture system.

How do you analyze biomechanics?

A common definition of motion capture states “the process of recording the movement of objects or people”. Like what you would expect, we use a series of cameras to record each pitcher, except we use twenty high-speed specialized motion capture cameras from Qualisys. Motion capture comes in two forms: marker-based and markerless. Marker-based motion capture is currently the gold-standard procedure for capturing and analyzing movement. Small reflective markers are placed on specific anatomical positions throughout each pitcher’s body, allowing the motion capture cameras to then track where the athlete is in space. By essentially talking amongst themselves, the cameras can figure out where they are in space not only to one another but to the athlete as well. This allows our computer software to recreate athletes as stick figures and thus, provides us with the joint angles and angular velocities needed to accurately describe exactly what you’re doing throughout the throwing motion.

Did you say markerless motion capture?

While marker-based motion capture is still considered the most accurate way to capture movement, markerless motion capture will eventually be a staple in our everyday practice. We currently use Theia Markerless which seamlessly integrates with our Qualisys system and provides top-level motion capture capability. Markerless motion capture is relatively new to the field, and thus, still has some tweaks to adjust in order to be as accurate as marker-based. This is because markerless motion capture, you guessed it, doesn’t use any reflective markers. Instead, a coding algorithm interacts with a series of video cameras recording simultaneously while surrounding the pitcher. Specialized computer software then models the athlete in 3D space using the viewpoints from each camera to determine body orientation. When using Theia Markerless software, this can be seen as a blue skeleton displayed over top of the athlete as shown below. The more cameras used, the more accurate the data can be as greater depth perception is created. This results in markerless motion capture being tiered based on accuracy. Simply put, the fewer video cameras you use, the less accurate your data will be.

Do you measure force?

No detailed biomechanics analysis is complete without the use of force plates. A force plate looks somewhat like a floor tile (except substantially more expensive) and is designed to measure the amount of force, specifically ground reaction force, exerted upon it. We utilize three research-grade Bertec force plates under the pitching mound and at landing. These force plates are fantastic at showing us how much force is being created as the pitcher pushes away from the mound and as they land. We can also examine the direction of the force as well. Within the biomechanics report, ground reaction force can be seen as a yellow arrow stemming from the grey rectangles on the floor within the skeletal model to the right.

How we leverage our biomechanics data

The resulting data from our biomechanics evaluation is displayed in a series of numbers and graphs. The numbers can either describe kinematics (i.e. joint angles) or kinetics (i.e. angular velocities, forces/torques) and can be seen throughout the report in table format or by scrolling the mouse over each graph. While it’s important to note what each athlete is doing at key time points in the delivery, such as stride foot contact and ball release, it’s even more important to understand how the athlete got to that position and how they move away from it. This is where the graphs come in handy as they provide a fantastic visual for describing the evolution of each movement. One of the best things about our online reports, generated with the help of our friends at Qualisys, is that you can move your mouse across the graph and view updated data from every millisecond down to the millimeter (yes, that’s very, very accurate and precise).

As you scroll down your biomechanics report, the data will start to point towards the same handful of movements responsible for your plateau in throwing velocity or chronic arm pain. The 2-4 movements we believe athletes should address first based upon the data are then highlighted at the top within a Feedback Tab. This tab showcases each movement, describes why the movement was selected to be within the Feedback tab, and provides drill work aimed at addressing the faulty movement. A basic sample of what our biomechanics report looks like can be found here.

With the UNO Pitching Lab housed in the University of Nebraska Omaha’s Biomechanics Research Building, it’s almost impossible to find a more thorough biomechanics evaluation. Not only do we have the privilege of using the best technology available, but we’re also surrounded by some of the brightest biomechanists in the country. Come check us out for yourself and see first-hand how our pitching biomechanics evaluations change the way we see the pitching motion.

See you then,

Tyler Hamer, Co-Founder & Lead Pitching Lab Researcher

Have an idea for our next post? Email us at bmchpitchinglab@unomaha.edu!