MLB Statcast Pitch Analysis: the Association between Active Spin and Opponent’s Batting Average

Baseball has often been described as a game of statistics and strategy, and current technology allows detailed examination of the game. One statistic measured concerning the movement of the ball is spin rate, the rotations per minute created by the pitcher when the ball is released from the hand. However, recent research has not examined the inclusion of pitchers’ spin rate in batter strategy. PURPOSE: The purpose of this study is to see if there is an association between the movement of breaking balls with the batting average of Major League Baseball batters. METHODS: A sample including 76 elite Major League Baseball pitchers, all male (age = 30.12 ± 3.68, mean ± sd), were taken from the 2019 MLB regular season using Statcast, Pitch F/x, and Trackman cameras. Statcast is used in Major League Baseball and collects the pitcher’s data revolving around their pitches (e.g., active spin, speed, whiff). Pitchers who had thrown a minimum of 2,500 pitches were included. The outcome was batting average, an aggregate number based on the number of players who faced an individual pitcher during the season. We performed multivariable linear regression models to regress batting average on curveballs and sliders separately. Covariates for assessment included pitcher demographics, active movement of the pitch, spin rate of the pitch, hits, at bats, percent of breaking balls thrown, pitch velocity, and number thrown versus right- and left-handed batters. RESULTS: After regression assumptions and steps were satisfied, 43.7% of the variation in batting average could be accounted for by the active spin of the slider, the number of sliders thrown, pitching hand, and the pitcher’s height. For every one-unit increase in active spin of the slider, batting average significantly decreased by 0.0013. Concerning curveballs, regression steps yielded a single-variable model, where 13.1% of the variation in batting average could be explained by the number of curveballs thrown. For every one-unit increase in the number of curveballs thrown, batting average significantly decreased by 0.00013. CONCLUSION: Variables significantly associated with batting average varied by whether a slider or a curveball was thrown; an increase in spin rate was significantly associated with a decrease in batting average for sliders thrown, but not for curveballs. The results of this study can be used by coaches as they prepare for games to enable the most favorable matchup between batter and pitcher. Future research should expand the timeline to include multiple MLB seasons to further corroborate these findings

Differences in Frontal Plane Knee Kinematics by Grip, Load, and Concentric Subphase in the Front Squat

Although the back squat is one of few exercises that has been extensively analyzed, the body of literature examining its counterpart, the front squat, is not as robust. The front squat is a vital exercise known for its quadricep development capabilities and unique front-rack positioning. This grip position renders the front squat more difficult, and thus proper form is more vital to prevent injury. PURPOSE: To evaluate the association between grip (standard front-rack, cross-grip, and strap-assisted), load (50% and 80% of 1-RM), and subphases of the concentric portion of the squat on frontal plane knee varus and valgus movement in the front squat. METHODS: Data was gathered from eight participants. Inclusion criteria were at least 60% on the Lower Extremity Functional Scale, self-report of performing front squats at least every two weeks for the past six months, and squatting below parallel. Two sessions were completed. First, consent, anthropometrics, and a 1-RM were obtained. Next, each subject was randomized to perform four repetitions of each grip at 50% and 80% of their 1-RM. During this session, a 29-marker set for 3D motion capture was used to collect joint angle data for each squat. We used data from knee frontal plane angles to analyze the concentric portion of the squat which we broke into subphases (1: 25%, 2: 50%, 3: 75% and 4: 100%) by frame. Only the second repetition from the left leg was analyzed. We performed a three-way repeated measures ANOVA for within-subject factors of grip technique (front-rack, cross-grip, strap-assisted), load (50%, 80%), and sub-phase of the concentric part of the squat (1, 2, 3, 4). We performed a sensitivity analysis with data from the second repetition of the right leg. Analyses were performed using R, version 4.0.3. Significance was set at p\u3c0.05. RESULTS: The eight participants (6 males, 2 females) were 173.10 ± 8.00cm (mean ± sd) in height, 78.20 ± 12.30kg in mass, 25 ± 3yrs of age, reported 6 ± 4 yrs of training experience, and had a 1-RM of 114.10 ± 31.00kg. There were no significant main effects for grip or load on knee varus/valgus movement in the frontal plane. However, there was a significant main effect for subphases of the concentric portion of the squat (p\u3c0.001). Except for between phases 3 and 4, there were significant differences between all pairwise comparisons of phases (p\u3c0.001 for all remaining except between 2 and 3, p = 0.002); whereas varus movement was found in phase 1, valgus movement was found in phase 2. Sensitivity analyses on the right leg yielded similar results. CONCLUSION: Our findings suggest that the subphases of the concentric portion of the front squat, but not grip or load, were significantly associated with varus/valgus movement of the knee. Therefore, strength coaches can choose a grip and load that is most appropriate for the specific athlete without significant impact on varus/valgus movement. However, regardless of grip or load, strength coaches should tune in closely to the concentric subphases of the front squat. In particular, to better prevent injury, strength coaches should focus on the first and second subphases phases where significant frontal plane movement may occur

Effects Of Community-Based Exercise Training Among Older Individuals With Metabolic Disease, Cardiovascular Disease, Or Muscle Atrophy

Exercise training is associated with increased health benefits such as improved quality of life, mental health, and physical functioning. PURPOSE: The purpose of this study is to quantify the effects of structured aerobic and resistance exercise training on body composition, functional tests, and quality of life in older individuals in a community-based facility. We hypothesized that at least moderate participation in the program would decrease fat mass, improve outcomes on grip and timed movement tests, and increase quality of life. METHODS: Twenty subjects who were members from a community-based institute participated in the study (7M:13F; 69.10 ± 6.40 yrs [mean ± sd]; 166.88 ± 10.52 cm; 76.40 ± 16.42 kg) and had metabolic or cardiovascular disease, or muscle atrophy. Subjects were expected to participate in 3, 30-min sessions/week for 8 weeks. The program was 30 min aerobic conditioning of intervals and 6–7 full-body resistance exercises and basic stretches. We measured height (cm), weight (kg), fat mass (kg), lean mass (kg), grip strength (kg), timed-up-go (TUG, s), 10-meter walk forwards (s), 10-meter walk backwards (a novel movement) (s), 6-minute walk tests (m), the Health-Related Quality of Life (CDC HRQOL-4) survey, and 36-Item Short-Form Health (SF-36), before and after the completion of exercise training. We performed paired t-tests on testing variables and the 8 subsections of the SF-36 and one-sample t-tests on the delta of questions on the HRQOL-4. Alpha \u3c0.05. RESULTS: There were no significant differences in any of the SF-36 subsections or testing variables (p \u3e 0.05) except for increased right-hand grip strength (2.02 ± 4.35 kg, p = 0.05) and decreased time in the backwards 10-meter walk (0.52 ± 0.88 s, p = 0.02). Concerning the HRQOL-4, no members had fair to poor self-rated health before or after the program, more members experienced fewer but non-significant physically unhealthy days (delta = -3.61 ± 8.67 days, p = 0.10), and a similar number of mentally unhealthy days and days when poor mental/physical health kept them from usual activities (p \u3e 0.05). CONCLUSION: These preliminary findings suggest that there may be clinically meaningful improvements in strength and novel movement in these older individuals after an 8-week prescribed and training program in the community setting. Different measurements of quality of life in this population should be explored

Reliability of Unilateral Isometric and Dynamic Leg Press Force and Power

Strength and power are critical components of athletic performance. Athletes commonly perform sport-specific movements off a single leg, but there are few reliable, easily administered unilateral leg force and power assessments. PURPOSE: To determine 1) the reliability of unilateral leg press maximal isometric force (MIF) and peak power tests and 2) the percentage of MIF that elicits unilateral peak power during a dynamic throw. We hypothesized that the tests would be reliable for the assessment of unilateral MIF and peak power and that unilateral peak power would be achieved at 50% of MIF. METHODS: Eighteen apparently healthy, recreationally active adults (17M: 1F; 27.4 ± 5.0 years; 1.78 ± 0.01 m; 93.5 ± 22.5 kg; 3159 ± 807 N bilateral MIF) completed three testing sessions. After a brief standardized warm-up, each subject performed three maximal unilateral isometric leg presses (MIF) with each leg at 90° of knee flexion on a modified leg press sled equipped with a force plate, linear encoder, and magnetic brake. Subsequently, the sled was unlocked and loaded in ascending fashion with 30%, 40%, 50%, 60%, and 70% of MIF; with an initial knee angle of 90°, subjects used maximal effort to throw each load twice, unilaterally, with each leg. Subjects rested and reset for 10-30 s between efforts. Data were sampled at 300 Hz, low pass filtered at 4 Hz, and peak instantaneous power (W) was calculated for each throw using the measured sled force and velocity. Intraclass correlation coefficients (ICC) were computed for the highest force and power repetition at each load across the three sessions. The ICC (95% CI) and peak power output were determined for both right and left legs. ICCs were considered excellent if ≥ 0.95, high if ≥ 0.90, good if ≥ 0.80, fair if ≥ 0.70, poor if ≤ 0.70, and very poor if ≤ 0.40. RESULTS: MIF showed good reliability between sessions [ICC: 0.85 (0.62, 0.94; left leg); 0.86 (0.58, 0.95; right leg)]. Unilateral peak power also showed good to high reliability between sessions across all loads: ICC (left leg) 30%: 0.91 (0.81, 0.96); 40%: 0.91 (0.81, 0.96); 50%: 0.95 (0.88, 0.98); 60%: 0.93 (0.86, 0.97); 70%: 0.81 (0.64, 0.92); (right leg) 30%: 0.95 (0.89, 0.98); 40%: 0.94 (0.87, 0.97); 50%: 0.92 (0.84, 0.97); 60%: 0.92 (0.84, 0.97); 70%: 0.90 (0.80, 0.96). Across all three sessions, peak power by the left leg was achieved at: 30% (11 of 18 participants); 40% (6 of 18); 50% (1 of 18). Peak power by the right leg was achieved at: 30% (13 of 18 participants); 40% (4 of 18); 50% (1 of 18). CONCLUSION: Unilateral leg press MIF and peak power can be reliably assessed with a modified leg press equipped with a force plate, linear encoder, and magnetic brake in a recreationally active population. Sport teams and coaches can use single leg isometric presses and throws as reliable methods to test their athletes’ unilateral force and peak power, respectively, with loads of 30-50% MIF appropriate for peak power measurement