analysis of throwing mechanics and ball flight in baseball pitchers
The purpose of this study was to quantify ball flight kinematics (ball speed, spin rate, spin axis orientation, rotation stability) and release location variability in the most common pitch types in baseball and softball and relate them to in-season pitching performance. A quantitative comparison of these pitches provided coaches with valuable information about the intricacies of ball manipulation and how this critical aspect of performance may be developed. Additionally, despite the emphasis place on pitching mechanics in practice, it is unclear how ball flight kinematics relate to pitching success.
Several novel findings were developed from this work:
- First known quantification of baseball flight motion of the change-up and slider pitches.
- Ball release variability and ball flight motion—two aspects of pitching to which much attention is given—were not correlated with fielding independent pitching in NCAA baseball pitchers.
- Pitching mechanics appear to be only one factor in a complex pitching strategy, at least in collegiate baseball athletes.
Follow-up analyses applied a “big data” approach to publicly-available Major League Baseball pitching data to analyze predictors of ulnar collateral ligament reconstruction surgery (Tommy John surgery).
Key findings of this study include:
- Confirmed that higher pitch count and faster pitch speed increase injury risk
- MLB pitchers who rested fewer days between games or who had threw a smaller repertoire of pitches were at increased injury risk
- Shorter stature and less pronounced horizontal release location also increased injury risk
- While much attention has been given to pitch count, many other factors appear involved in injury risk among MLB pitchers. Adding one additional pitcher to the rotation could significantly impact the time and money lost on injured MLB pitchers.
- The machine learning approach achieved excellent predictive ability with a relatively limited dataset; future work that adds information about practice, bullpen, and training room habits could provide even better insight
relationship between on-field biomechanics and femoroacetabular impingement (fai) in elite athletes
Hip injuries are a growing issue in high school, collegiate, and professional sports. Femoroacetabular impingement (FAI) is common orthopaedic condition that often underlies these injures. Preventing FAI has proven difficult thus far as little is known about how the condition develops. Additionally, invasive surgery is accepted as the optimal treatment method, requiring considerable expense and a lengthy rehabilitation period. In order to enhance prevention, treatment, and rehabilitation programs, it is essential to acquire a more thorough understanding of FAI. To do so, we examined the biomechanics of elite Division I and professional athletes from sports with a high incidence of FAI (hockey and baseball) while they perform on-ice/on-field game-like movements. Wearable sensors worn underneath the player’s standard equipment measured precise body motions in the trunk and lower limbs during the tasks, providing the first comprehensive database of hip function in a high-risk FAI population. Additionally, radiological scans of each athlete’s hips were used to determine how the structural features of the hip influence movement during dynamic tasks.
The in-vivo hip mechanics were evaluated in two athletic populations at-risk for FAI: 1) elite ice hockey goaltenders as they performed on-ice game-like drills, and 2) NCAA baseball pitchers as they threw their full pitching repertoire in their practice facility.
In ice hockey goaltenders, we found:
- The stopping motion, to which little attention has been given, produces greater hip motion than the butterfly.
- This suggests that multiple postures must be considered when treating and preventing FAI and may explain why skaters also experience FAI.
- X-ray hip measures were poor predictors of on-ice hip motion.
- All hips examined exhibited alpha angles (an x-ray indicator of FAI) that were above the FAI threshold but only one was symptomatic.
- Evaluating the athlete in a more realistic environment reveals novel and potentially more valuable findings that static examination.
In-field Objective Evaluation of the Functional Movement screen
Effective and reliable assessment of injury risk in the athletic population is challenging. We developed an objective evaluation of the Functional Movement Screen (R) using body-worn inertial measurement units. This method was used with high-level female basketball athletes to assess risk of anterior cruciate ligament (ACL) injury and compared to subjective ratings by trained sports medicine staff.
The key finding was that
- Instrumented screening improved evaluation of subtle movement deficits, particularly in complex movements such as the overhead squat.
- Objective methods can enhance the subjective rating by providing consistent and unbiased simultaneous evaluation in multiple planes of motion
sport collision simulation & protective equipment testing
In collaboration with the Biomechanics Research Laboratory in the Department of Mechanical Engineering, we are quantifying the frequency and severity of athlete collisions in football and basketball, and developing innovative methodologies to recreate these impact scenarios in the laboratory. By accurately simulating in-game impacts, we can test and develop next-generation protective equipment that allow freedom of movement, while attenuating collision forces to non-injurious levels.