Welcome to Driveline’s pitching research page

Here is where we will start our review of studies and their relation to baseball.

You can see a longer list of the studies we have collected here.

If have any interesting studies to share you can send them to support@drivelinebaseball.com and we may review and post them with attribution.

How to use this page:

We do our best to experiment and validate much of the research that we read. We will link to the abstract of each paper to encourage you to do your own investigation/observation/experimentation. These studies should be taken as a jumping point for your own research. Each is simply a piece of the puzzle not law of the land.

“If you don’t experimentally validate research you picked up out of a textbook or published paper, that’s not science. That’s faith.”

New Studies

Pectoralis Minor Contracture in Throwing Shoulders of Asymptomatic Adolescent Baseball Players (Open Access)

This study investigated further adaptations to throwing in youth athletes, specifically the length of the pectoralis minor (PM). Because of the way the muscle attaches to the scapula, shortening of the PM can change the position of the scapula and its range of motion. The authors hypothesized that the PM would be shorter in the throwing shoulder when compared to the non-throwing shoulder.

Participants were between 14-18 years old, had played organized baseball for at least one year, and had no pain in either shoulder. All 49 participants were from one baseball-training facility. Pectoralis-minor length was measured supine, sitting at rest, and sitting with the shoulder in maximal external rotation.

The study found that baseball players have significant differences in PM length and static scapular measurements in their throwing shoulders when compared to their non-throwing shoulders. While it is not known what the exact clinical significance of this is, it is enough reason to encourage athletes to include stretching of the PM in their routines.

Early Sport Specialization: Effectiveness and Risk of Injury in Professional Baseball Players

One-hundred and two current professional baseball players of the Atlantic League completed an anonymous seven-question survey. It asked if they specialized in baseball prior to high school and how many surgeries they had as a professional and high schooler that required them to sit out a year.

Sport specialization was defined as “intense, year-round training in a single sport with the exclusion of other sports.”

Of all 102 athletes, 48% (50 athletes) stated that they had specialized in baseball at an early age, with the mean age being 8.91 years old (3.7 SD). Those who specialized early reported more serious injuries during their professional baseball career than those who did not. However, the study did not find a relationship between specialization and youth injury.

While there isn’t a straightforward link between early sports specialization and success or injury, there will always be multiple variables at play. If athletes do choose to specialize in any sport, they should make sure that they take adequate time off during the year.

Biomechanical Comparison of the Interval Throwing Program and Baseball Pitching: Upper Extremity Loads in Training and Rehabilitation

A biomechanical comparison of torque measured fastball pitching, variable-effort pitching, and throwing various flatground distances.

Twenty-nine healthy college baseball pitchers threw from flatground at distances of 18, 27, 37, 55 and off a mound. The study measured kinetic values for humeral internal rotational torque (HIRT) and elbow-valgus load (EVL).

The researchers found no statistically significant difference between any of the flatground distance and throwing from the mound. The values were the highest when throwing from the mound at full intent.

This is an interesting finding, considering that even though the values were higher off the mound, they were not significantly different. This suggests that, even at shorter distances and lower velocities, pitchers are experiencing similar biomechanical loads to pitching—even though the common assumption by coaches and players is that flatground throws are less stressful.

Pitchers were also asked to pitch at various intent levels. There were significant differences when asked to throw at 60% effort when compared to 100% effort. However, it was also seen that pitchers are not very good at measuring their own intent levels. At 60% perceived effort, pitchers generated forces of 76% and ball speeds of 84% of maximum effort. This suggests that even though lower-intent mound work is less stressful than pitching at full intent, it isn’t as low as many coaches and players would expect.

These are the two big takeaways: first, flatground throws may be less stressful than pitching on a mound but there is not as large of a difference as many believe. Second, pitchers are not good at adjusting their own intent levels, meaning that even lighter effort throws are being thrown harder than coaches and players intend.

A Biomechanical Comparison of Pitching From a Mound Versus Flatground Adolescent Baseball Pitchers

Fifteen adolescent pitchers between the ages of 9 and 14 were recruited for the study. The athletes were asked the throw 7 pitches, from a mound and flatground, to a standard strike zone 45 feet away.

The researchers found that, for adolescents, pitching off the mound was slightly more stressful than pitching off of flatground: 33.6 Nm vs 31.7 Nm for the shoulder and 33.3 Nm vs 31.4 Nm for the elbow.

The researchers also proposed that a 6% increase in stress, though small, was equivalent to the percentage decrease in the timing of specific phases of the pitching motion. This may imply that the slope of the mound may cause a decrease in the time available to complete a pitch, which may cause a change in kinetic values.

It’s unknown if this relationship is the same for adult pitchers.

Do Baseball Pitchers Improve Mechanics After Biomechanical Evaluations?

Forty-six baseball pitchers were evaluated twice in a biomechanical analysis to see if there were any changes between analysis. The average time between analysis was 12 months with a range of 2 to 48 months. Ten full-effort fastballs were used in the study to compare evaluations.

Pitchers were judged to have “flaws” in their mechanics if they were outside of the normative range, either too high or too low. Overall there were 138 “flaws” detected in the pretest and 61 (44%) of them were corrected by the second test. The 46 pitchers had 223 biomechanical parameters in the normal range and 41 parameters (18%) developed new “flaws” by the second evaluation.

The study didn’t look at any specific teaching or coaching methodology, which raises the interesting point that mechanics are fluid and change over time at all ages. However, there wasn’t a big enough group to compare if amateurs or professional were able to make more changes than the other.

The Role of Pelvis and Thorax Rotation Velocity in Baseball Pitching

Using marker sets on the thorax (upper body) and pelvis, the researchers studied amateur players too see how rotation velocity affected throwing velocity.

The researchers found that maximal pelvis and thorax rotation velocity, by themselves, were not associated with throwing velocity. However, the researchers did find a relationship between separation and velocity. Separation was defined as the gap of time between maximum pelvis rotational velocity and thorax rotational velocity.

The difference between peak velocities is incredibly small. The researchers believe that an increase in separation between peak velocities by 10 ms on average would increase throwing velocity by 1 mph.

Another interesting note is that the average rotation velocity profile of all eight pitchers had peak velocities before front-foot contact. Whether there is a larger difference between high and low velocity throwers is unknown.

Correlation of Torque and Elbow Injury in Professional Baseball Pitchers

Through a mixed-model analysis, a comparison of elbow-valgus (EV) torque throughout the pitching motion found a near-significant statistical trend between the injured and non-injured groups. A further analysis of differences determined that a statistically significant difference occurred only at the event of maximum external rotation (p=.0130).

At other events, a statistically significant difference of EV torque did not occur. At maximum external rotation, the non-injured group had a mean EV torque of 74.7 Nm (± 22.38) and the injured group had a mean EV torque of 91.62 Nm (± 22.96).

The non-injured group also experienced less maximum shoulder external-rotation (ER) torque at maximum external rotation. Max ER torque is the force that the arm lies back into external rotation.

Other studies have examined differences of elbow-valgus torque at maximum external rotation, but it is clear that maximum ER is the point at which there is the most stress on the elbow. Furthermore, the force that the arm lies back into external rotation is an important factor in elbow torque.

On-the-Field–Resistance-Tubing Exercises for Throwers: An Electromyographic Analysis (Open Access)

This study investigated the  activity of various shoulder musculature while performing rubber-tubing exercises. The subscapularis, supraspinatus, teres minor, and rhomboid major were measured with indwelling electromyography. The sternal portion of the pectoralis major, anterior deltoid, middle deltoid, latissimus dorsi, serratus anterior, biceps brachii, triceps brachii, lower trapezius, and infraspinatus muscles were assessed using surface electromyography measurements.

Fifteen athletes performed the following exercises: shoulder extension, shoulder flexion, internal-humeral rotation at 90 degrees of abduction, external-humeral rotation at 0 degree of abduction, internal-humeral rotation at 90 degrees of abduction, external-humeral rotation at 90 degrees of abduction, high-, middle-, and low-scapular rows, scapular punches, throwing acceleration, and throwing deceleration.

The study didn’t aim to conclude which exercises were best for specific muscles; rather, it sought to conclude which exercises facilitated the greatest activation in the most muscles.

Seven exercises resulted in at least moderate activation (>20% of MVIC) of all muscles tested: shoulder extension, shoulder flexion, throwing deceleration, throwing deceleration, external-humeral rotation at 90 degrees of abduction, scapular punches, and either high- or low-scapular rows.

Kinematic and Temporal Parameters of High School Baseball Pitchers in Different Velocity Groups (Open Access)

The researchers compared twelve kinematic and nine temporal parameters between the ten pitchers with the greatest hand velocity and the ten pitchers with the lowest hand velocity.

There were no differences between any of the temporal parameters, but researchers did find differences in a number of kinematic variables. The high velocity group had greater peak trunk rotational velocity, elbow angular extension velocity, and maximum knee extension angular velocity at ball release.

Surprising to the researchers, they found no differences in maximal external shoulder rotation or forward trunk tilt between the two groups. Theses two variables have been shown to be significant in other studies. Because of this, the authors note that there may be larger differences between high school, college, and professional pitchers than currently believed.

Weighted Ball Training

Reviews of peer reviewed research involving many forms of weighted ball training.

Biomechanics

Short Reviews of peer reviewed biomechanics based pitching research. Includes reviews of long toss as well.

Baseball Reviews

Research on a variety of baseball content, including performance, age, and testing measures.

Pitching Mechanics

Research on the kinetic chain and pitching mechanics.

Youth Pitchers

Research on youth pitching mechanics and injury factors.

Elbow Injuries and Tommy John

Research on Tommy John rates of return and performance as well as other elbow injuries.

Shoulder Injuries

Research on the scapula and shoulder strength and injury risk factors.

Verbal Cues

Research on communicating with athletes through cueing

Recovery

Research on different recovery modalities (Marc Pro, EMS) and Heart Rate Variability (HRV)

Ground Reaction Forces

Research on the lower half and ground reaction forces in the pitching delivery.

Weight Room and Workouts Training

Research on lifting and medicine ball work in relation to baseball.

Other Throwing Sports

Research on other throwing sports that may have relatable findings to baseball.