Tag Archives: baseball

Using K-Motion Technology to Achieve the Perfect Baseball Swing

The question on every baseball player’s mind is: besides more practice, how can I improve my batting skills?

Most people would assume it comes down to practice and strength training, but according to Joe Lemire, a sports reporter at SportTechie, the answer actually lies in the biomechanics of the swing. An in-depth description of the intricacies of the biomechanics that are involved in a baseball swing can be found in David Fortenbaugh’s dissertation here.

A photo of a baseball player mid-swing, making contact with the ball in a game.
Photo by Chris Chow on Unsplash

Many professional baseball teams and some training facilities, including Driveline Baseball in Seattle, have turned to using a K-Motion vest to record and analyze different aspects of a baseball swing. This wearable technology started as an analysis for golf swings, but the technology has now been implemented in baseball. Initial installations of this technology were much more expensive and not portable, but engineers have found ways to translate these technologies into wearable devices that can be used in more natural situations.

Prior methods of swing analysis left many unanswered questions and didn’t provide athletes with proper information for improvement. The K-Motion vest collects data on the speed and bend in a player’s torso and pelvis, and the rotation of their body. The portability of the vest allows for it to be used in game-like scenarios and provide useful information. The data that can be extracted from the K-Motion vest can be used to fix mechanical flaws in a player’s swing.

A photo of a man wearing the K-Motion vest, showing that a sensor sits on the top of the spine and at the tailbone.
Photo from Lemire, SportTechie 2018 (Courtesy of K-Motion)

The K-Vest uses four different sensors to measure the rotational velocities of the torso, hips, lead arm, and bottom hand. The four sensors are placed above the elbow on the lead arm, on the back of the lead hand, on the tailbone, and on top of the thoracic spine. The velocities are compiled into a graph, and the peak velocity of each sensor can be analyzed to track the transfer of energy throughout the swing. Through use of the K-Vest, they have found that to elevate one’s hitting ability comes down to the transfer of energy from pelvis and torso rotation to their arms and wrists.

In order to fix the mechanics of a swing, the system has to obtain an understanding of what a good swing is by compiling data from a variety of professional players. On the graph produced with each swing, the range for pro hitters is displayed to give the user an idea of how they compare. Some more information about the kinematic analysis of the data can be found here.

An example of the data that the user receives from the system and how it can be used to improve a player’s swing can be seen in this video:

Though already proven useful in baseball and golf, people are finding that it can also be useful in volleyball, running, skiing, and other forms of physical activity. The use of this technology has become much more common as professional players have found the feedback to be constructive.

For more information about this technology, check out K-Motion’s website, and see here how it’s being used in golf.

What is Tommy John surgery?

Baseball card of Tommy John for the Los Angeles Dodgers
From Zellner, “A History and Overview of Tommy John Surgery,” Orthopedic & Sports Medicine Specialists

In July of 1974, Tommy John, pitcher for the Los Angeles Dodgers, felt a twinge in his throwing arm, and could no longer pitch. Dr. Frank Jobe tried a new kind of surgery on John’s elbow, and after missing only one season, Tommy John returned to the mound in 1976 and continued pitching until 1989.

How?

The surgery which bears Tommy John’s name is by now a common buzzword in the baseball community. Over 500 professional and hundreds of lower level players have received this treatment, but even the most avid fan may still be unsure what it means.

Tommy John surgery is the colloquial name for surgery on the Ulnar Collateral Ligament (UCL). This ligament is vital to the elbow, especially in the throwing motion. Injury to the UCL accrues over time; fraying and eventual tearing occurs after repeated and vigorous use. Baseball pitchers, throwing around 100 times per game and at speeds upwards of 100 mph, put themselves in danger of UCL injury.

Location of the Ulnar Collateral Ligament in the human arm, shown on a baseball pitcher.
Image from Wikimedia Commons.
Tendons in the elbow joint, with the Ulnar Collateral Ligament marked
Image from Wikimedia Commons

What can be done when a player injures his or her UCL?

Prior to 1974, not much. Ice and rest, the most common suggestions, would do little to improve serious UCL damage. A “dead arm” spelled the end of a player’s career. Dr. Jobe would change that. 

Jobe removed part of a tendon from Tommy John’s non-pitching forearm and grafted it into place in the elbow. John’s recovery required daily physical therapy before slowly starting to throw again.

Since Jobe’s pioneer surgery on Tommy John, most patients undergo a similar kind of reconstruction procedure. A tendon from either the forearm (palmaris longus) or the hamstring (gracilis), is looped through holes drilled in the humerus and ulna, the bones of the upper arm and inner side of the forearm. In some modern cases, the hope is to repair the UCL with a brace that lets it heal itself rather than total replacement. This allows for faster recovery time because the new blood vessels that have to form in traditional ligament replacement are unnecessary. In either case, athletes recovering from UCL surgery, a procedure which itself takes less than two hours, typically require at least a year to restore elbow stability, function, and strength.

Some misconceptions about Tommy John surgery exist. One 2015 study found that nearly 20% of those surveyed believe the surgery increases pitch speed. However, increase in pitch speed may be affected more by the extensive rehabilitation process rather than the new tendon itself.

The study also found that more than a third of coaches and more than a quarter of high school and collegiate athletes believe the surgery to be valuable for a player without an injured elbow. This perception of Tommy John surgery makes it seem like a superhuman kind of enhancement, as if out of The Rookie of the Year, or worse, it becomes like a performance enhancing drug. In reality, a replacement UCL at best replicates normal elbow behavior. A procedure capable of creating a superhero might be attractive, but for now, Tommy John surgery just helps players get back in the game.

 

For further information:

 

How Many MLB Players Have Had Tommy John Surgery?

What Makes Someone More Likely to Tear Their UCL?

It takes a lot to make a professional athlete collapse to the ground during a game. After throwing a pitch on September 14, 2019, Toronto Blue Jays pitcher Tim Mayza knelt on the side of the mound while clutching his arm, expecting the worst. The next day, MRI revealed that what he had feared: Mayza had torn his Ulnar Collateral Ligament (UCL).

player following through after throwing baseball
Photo by Keith Johnston on Unsplash

Because of UCL reconstruction, or Tommy John, surgery, this injury is no longer the career death-sentence that it once was, but there is still a long road ahead for Mayza. He probably will not pitch in a game again until 2021. Sadly, this injury is only becoming more and more common among MLB pitchers. In the 1990s, there were 33 reported cases of UCL tears by MLB pitchers. In the 2000s, this number more than tripled to 101. From 2010 to the beginning of the 2015 MLB season, 113 UCL reconstruction surgeries had already been conducted. It has become so common that surgeons have called it an epidemic, and researchers in the US and abroad are attempting to find a way to combat this increase.

Digital image of elbow joint, with a small, red tear in the UCL
Orthopaedic and Neurosurgery Specialists, 2019

The UCL connects the ulna and humerus at the elbow joint, and its purpose is to stabilize the arm. During the overhead pitching motion, the body rotates in order to accelerate the arm and ball quickly, putting a large amount of stress on the UCL. In fact, according to a study by the American Sports Medicine Institute, the torque, or twisting force, experienced by the UCL during pitching is very close to the maximum load that the UCL can sustain.

Recently, many studies have investigated factors that could make pitchers more susceptible to UCL injuries, with a hope of identifying ways to prevent them. One of the biggest findings has been the correlation between UCL tears and pitch velocity. According to a study from the Rush University Medical Center, there is a steady increase in the frequency of UCL tears as max velocity increases. This makes intuitive sense, as more torque would be required to accelerate a baseball to the higher velocities. While this finding does have a very strong correlation, it does not help the players avoid injuries. Pitchers are unlikely reduce their velocity because it would also decrease their effectiveness, so another answer must be found.

The University of Michigan conducted another study, and found that, in addition to velocity, the number of rest days between appearances decreased by just under a full day for pitchers who later needed Tommy John surgery. While this does not seem like a large number, starting pitchers typically only receive 4 days of rest between starts, so the extra .8 days is equivalent to a 20% increase in rest time.

Because of these findings, the MLB has increased the max roster size from 25 to 26 for the 2020 season, with the hope that teams will use the extra player to reduce the frequency that each pitcher is used. In addition, pitch counts in Little League Baseball have had a positive effect on youth injuries. This can be explored further here. This discovery has already made a tangible impact on Major League Baseball, and hopefully more findings will reduce the rate of UCL tears in the future.

Biomechanics of Pitching: Pushing Limits on the Shoulder and Elbow

Aroldis Chapman of the New York Yankees holds the Guinness World Record for the fastest recorded baseball pitch at 105.1 MPH; a record that has held for almost a decade. Why has no one been able to top his record? — An answer to this question may be found in the biomechanical limits of the human shoulder and elbow during the throwing motion.

As a little background on the subject, the throwing motion can be broken down into six separate phases: windup, stride, arm cocking, arm acceleration, arm deceleration, and follow-through as can be seen below.

Images depicting the six phases of the throwing motion.
Image from the www.physio-pedia.com article “Throwing Biomechanics”

Of the six phases only two are the main instances of injury: the arm cocking phase and the arm deceleration phase.

Injury can occur in the labrum and rotator cuff in the shoulder, as well as in the ulnar collateral ligament (UCL) in the elbow during the throwing motion. In pitchers the stresses are at their extremes due to the unique positions the arm reaches, thus leading to a higher chance of failure in the muscles and ligaments of the arm.

Torques and forces on the shoulder and elbow at the end of the arm cocking phase.
Image from The American Journal of Sports Medicine article “Kinematics of Baseball Pitching with Implications About Injury Mechanisms” by Fleisig et al.

At the end of the arm cocking phase, the arm is in a position of 160° to 180° from the horizontal and puts the arm in the position to accelerate the ball forward. According to one study, extreme torques of 64 N-m and 67 N-m are applied at the elbow and shoulder, specifically loading the rotator cuff and the UCL. Furthermore, the anterior (forward) force at the shoulder of 310 N loads the labrum in such a way that may cause it to tear. The feeling of these loads is equivalent to holding 60 lbs in your hand in the position shown on the right!

Force and position of the shoulder and elbow during the arm deceleration phase.
Image from The American Journal of Sports Medicine article “Kinematics of Baseball Pitching with Implications About Injury Mechanisms” by Fleisig et al.

During the arm deceleration phase the arm is in a position of 64° from the horizontal and the shoulder resists the extreme speed and acceleration it just endured. An article showed that during the deceleration phase the arm experiences angular velocities in the shoulder of almost 7,000 degrees/sec making it one of the fastest known human motions. That is about 1,200 RPM which is comparable to the rotational speed of some car engines during cruise control, while traveling at about 50 MPH! Additionally, the rotator cuff and the labrum take the brunt of the 1090 N (245 lbs) compressive force needed to slow down the arm and it is enacted in just an instant!

According to one article, the limiting factor on pitch speed is that the force pitchers apply to their UCL is at the limit of what makes it tear. This means that attempting to throw any faster would result in the UCL tearing! In summary, pushing to gain more MPH on the fastball would mean even higher loads and thus more demand from the shoulder and elbow despite already being at their limits.

All in all,  biomechanical data shows that limits in the rotator cuff, labrum, and especially the UCL explain why  Aroldis Chapman’s record has been preserved for almost a decade and why the chances of throwing any faster are almost impossible. However, in the world of sports, limits and impossibilities are just waiting to be broken.

 

Sources and Additional Reading:

“Fastest Baseball Pitch (Male)” https://www.guinnessworldrecords.com/world-records/fastest-baseball-pitch-(male)/

“Kinematics of Baseball Pitching With Implications About Injury Mechanisms” https://journals.sagepub.com/doi/pdf/10.1177/036354659502300218

“Biomechanics of baseball pitching: A preliminary report” https://journals.sagepub.com/doi/pdf/10.1177/036354658501300402

“Why It’s Almost Impossible For Fastballs to Get Any Faster” https://www.wired.com/story/why-its-almost-impossible-for-fastballs-to-get-any-faster/

“Throwing Biomechanics” https://www.physio-pedia.com/Throwing_Biomechanics

“Your car’s engine rpm at highway cruising speeds” https://www.team-bhp.com/forum/technical-stuff/171572-your-cars-engine-rpm-highway-cruising-speeds.html

Striking Out the Myths behind the Curveball

Anybody who has played baseball growing up was probably told “Don’t start throwing a curveball until you are ‘X’ years old.” That “X” in there for the age was normally around fifteen or sixteen years old depending on who you asked. When an eager, young ball player responded with “Why,” it was normally answered by “Because you will hurt your elbow and shoulder.” No sixth or seventh grade kid is really going to question that statement beyond asking another adult, and subsequently getting the same answer. Likewise, no youth baseball coach has really put in the effort to research whether or not learning to throw a curveball is detrimental health of young athletes.

A study was recently conducted by professionals at Elite Sports Medicine at Connecticut Children’s Medical Center to find out the answer. The study was aimed to analyze the shoulder and elbow joints of several teenage pitchers as they threw multiple fastballs and curveballs. They were specifically looking at the moments put on the elbow and shoulder and comparing those between pitches. A moment is a measure of a force on an object and the distance away from the object the force is being applied, mostly resulting in rotation. A moment can also be thought of as torque.

This image shows the grip and wrist position for a curveball
From McGraw, How to Play Baseball, a Manual for Boys

After warming up, the athletes selected for the study had reflective markers placed on their body. These markers assisted in gathering information for “3-Dimensional motion analysis”. This analysis allows the researchers to record “kinematic and kinetic data for the upper extremities, lower extremities, thorax, and pelvis” for both the fastball and the curveball. The researchers found that the moments in the shoulder and in the elbow are lower when throwing a curveball compared to a fastball. This means that the rotational force put on the joints is actually less severe in a curveball than a fastball. The only thing found that is more intense in a curveball than a fastball is the force on the wrist ulnar, which is used when making the motion trying to touch the wrist to the pinky finger. The wrist and forearm motion and forces were the only significant differences between the two pitches.

From this data it is easy to see that the reason for not learning curveballs at a young age has nothing to do with shoulder and elbow injury. There may be a reason related to wrist injury, but that is yet to be explored. A fastball is actually harder on the joints than a curveball. For whatever reason, youth coaches have always preached not to throw curveballs until you absolutely need to. They may have their reasons, but science has shown that it is not realistic to blame injuries.

For further reading on this topic, please see these articles from Driveline Baseball, The New York Times, and Sports Illustrated.