Interaction Between Age and Change in Velocity During a Baseball Training Program

BackgroundWeighted-baseball training programs are used at the high school, collegiate, and professional levels of baseball. The purpose of this study was to evaluate the effects of a six-week training period consisting of weighted implements, manual therapy, weightlifting, and other modalities on shoulder external rotation, elbow valgus stress, pitching velocity, and kinematics.HypothesisA six-week training program that includes weighted implements will increase pitching velocity along with concomitant increases in arm angular velocities, joint kinetics, and shoulder external rotation.MethodsSeventeen collegiate and professional baseball pitchers (age range 18–23, average: 19.9 ± 1.3) training at Driveline Baseball were evaluated via a combination of an eight-camera motion-capture system, range-of-motion measurements and radar- and pitch-tracking equipment, both before and after a six-week training period. Each participant received individualized training programs, with significant overlap in training methods for all athletes. Twenty-eight biomechanical parameters were computed for each bullpen trial, four arm range-of-motion measurements were taken, and pitching velocities were recorded before and after the training period. Pre- and post-training period data were compared via post-hoc paired t tests.ResultsThere was no change in pitching velocity across the seventeen subjects. Four biomechanical parameters for the holistic group were significantly changed after the training period: internal rotational velocity was higher (from 4,527 ± 470 to 4,759 ± 542 degrees/second), shoulder abduction was lower at ball release (96 ± 7.6 to 93 ± 5.4°), the shoulder was less externally rotated at ball release (95 ± 15 to 86 ± 18°) and shoulder adduction torque was higher (from 103 ± 39 to 138 ± 53 N-m). Among the arm range of motion measurements, four were significantly different after the training period: the shoulder internal rotation range of motion and total range of motion for both the dominant and non-dominant arm. When the group was divided into those who gained pitching velocity and those who did not, neither group showed a significant increase in shoulder external rotation, or elbow valgus stress.ConclusionsFollowing a six-week weighted implement program, pitchers did not show a significant change in velocity, joint kinetics, or shoulder external rotation range of motion. When comparing pitchers who gained velocity versus pitchers who did not, no statistically significant changes were seen in joint kinetics and shoulder range of motion.

Objectives:Pitch velocity has become an increasingly popular metric by which pitchers are graded and compared. Training programs that utilize weighted balls have been effective in increasing velocity but at the cost of increased injury risk. The purpose of this study was to determine if a baseball pitcher-training program utilizing lighter baseballs could increase fastball velocity without increasing injury risk. The author’s hypothesized that the training program with lighter baseballs would increase fastball velocity without causing injuries during the training program to the participantsMethods:All baseball pitchers who participated in a 15-week pitching mechanic and velocity training program were included. Training program was broken down into three phases, and each participant went through the same program. Lighter balls (4oz and 3oz) and standard baseballs (5oz) were utilized as part of the training program. Weighted (heavier) balls were not used. Velocity was measured at four time points throughout the program. Injury rates for all players were recorded throughout the entire program.Results:48 male pitchers aged 10-17 (average age: 14.7 +/- 1.8) years started the program and 44 had complete data and were included in the analysis. No pitcher sustained a baseball-related injury while participating in the training program (one player broke his ankle playing basketball, one player moved, one did not have baseline velocity data, and one experienced biceps soreness after participating in back to back showcases against recommendations). Fastball velocity increased by an average of 4.8mph (95% confidence intervals 4.1 - 5.5mph). Overall 43/44 players (98%) had an increase in fastball velocity over the course of the program.Conclusions:A 15-week baseball pitcher-training program with lighter baseballs significantly improved pitching velocity without significantly increasing injuries. Lighter baseballs should be considered instead of weighted baseballs when attempting to increase a pitcher’s velocity.

BackgroundIn mechanically ventilated patients, an increase in cardiac index during an end-expiratory-occlusion test predicts fluid responsiveness. To identify this rapid increase in cardiac index, continuous and instantaneous cardiac index monitoring is necessary, decreasing its feasibility at the bedside. Our study was designed to investigate whether changes in velocity time integral and in peak velocity obtained using transthoracic echocardiography during an end-expiratory-occlusion maneuver could predict fluid responsiveness.MethodsThis single-center, prospective study included 50 mechanically ventilated critically ill patients. Velocity time integral and peak velocity were assessed using transthoracic echocardiography before and at the end of a 12-sec end-expiratory-occlusion maneuver. A third set of measurements was performed after volume expansion (500 mL of saline 0.9% given over 15 minutes). Patients were considered as responders if cardiac output increased by 15% or more after volume expansion.ResultsTwenty-eight patients were responders. At baseline, heart rate, mean arterial pressure, cardiac output, velocity time integral and peak velocity were similar between responders and non-responders. End-expiratory-occlusion maneuver induced a significant increase in velocity time integral both in responders and non-responders, and a significant increase in peak velocity only in responders. A 9% increase in velocity time integral induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 89% (95% CI 72% to 98%) and specificity of 95% (95% CI 77% to 100%). An 8.5% increase in peak velocity induced by the end-expiratory-occlusion maneuver predicted fluid responsiveness with sensitivity of 64% (95% CI 44% to 81%) and specificity of 77% (95% CI 55% to 92%). The area under the receiver operating curve generated for changes in velocity time integral was significantly higher than the one generated for changes in peak velocity (0.96 ± 0.03 versus 0.70 ± 0.07, respectively, P = 0.0004 for both). The gray zone ranged between 6 and 10% (20% of the patients) for changes in velocity time integral and between 1 and 13% (62% of the patients) for changes in peak velocity.ConclusionsIn mechanically ventilated and sedated patients in the neuro Intensive Care Unit, changes in velocity time integral during a 12-sec end-expiratory-occlusion maneuver were able to predict fluid responsiveness and perform better than changes in peak velocity.

Transcranial Doppler blood velocity measurement—the effect of changes in velocity profile

Ulnar collateral ligament (UCL) reconstruction (UCLR) is commonly performed in Major League Baseball (MLB) pitchers, and there remain limited data on off-speed pitch performance in those that return to play after reconstruction. The purpose of this study was to evaluate the effect of primary UCLR on curveball (CB) and change-up (CU) pitch performance in terms of velocity along with novel pitching metrics including spin rate, hard-hit rate, and whiff rate. It was hypothesized that post-UCLR off-speed pitch spin rates, velocity, and whiff rate would decrease significantly compared with pre-UCLR levels, while hard-hit rates would increase. Cohort study; Level of evidence, 3. Pitchers who underwent UCLR and returned to MLB level of play were identified from public records from 2016 to 2019. The Statcast system was used to collect spin rate, velocity, hard-hit, and whiff rate data for CB and CU pitches for preinjury seasons, as well as the first 2 seasons after return from UCLR. A matched-pair analysis was performed by matching each pitcher to an uninjured healthy pitcher from the same draft class and round. A total of 29 pitchers met inclusion criteria and threw the pitches of interest. There were no statistically significant changes in CB or CU mean spin rate, pitch velocity, hard-hit rate, or whiff rate when comparing preinjury levels with the first and second seasons played after reconstruction. There were no significant differences in any pitching metrics when comparing the UCLR cohort with the healthy matched-pair cohort. The mean total number of CU pitches significantly decreased in the first season after UCLR (154.0 vs 67.9; P = .04) and compared with the matched-pair cohort at 1 year (67.9 vs 233.2; P = .001). Pitchers also threw fewer total pitches in the first season after returning from UCLR compared with preinjury baselines and healthy matched pairs. The results of this study demonstrate that pitchers who undergo UCLR and return to the MLB level can expect similar off-speed pitch performance in comparison with their preinjury levels and with pitchers without UCL injury.

It has been recognized that stress perturbations in sediments induced by salt bodies can cause elastic-wave velocity (seismic velocity) changes and seismic anisotropy through changing their elastic parameters, thus leading to difficulties in salt imaging. To investigate seismic velocity changes and seismic anisotropy by near-salt stress perturbations and their impacts on salt imaging, taking the Kuqa depression as an example, we have applied a 2D plane-strain static geomechanical finite-element model to simulate stress perturbations and calculate the associated seismic velocity changes and seismic anisotropy; then we used the reverse time migration and imaging method to image the salt structure by excluding and including the stress-induced seismic velocity changes. Our model results indicate that near-salt stresses are largely perturbed due to salt stress relaxation, and the stress perturbations lead to significant changes of the seismic velocities and seismic anisotropy near the salt structure: The maximum seismic velocity changes can reach approximately 20% and the maximum seismic anisotropy can reach approximately 10%. The significant changes of seismic velocities due to stress perturbations largely impact salt imaging: The salt imaging is unclear, distorted, or even failed if we exclude near-salt seismic velocity changes from the preliminary velocity structure, but the salt can be better imaged if the preliminary velocity structure is modified by near-salt seismic velocity changes. We find that the locations where salt imaging tends to fail usually occur where large seismic velocity changes happen, and these locations are clearly related to the geometric characteristics of salt bodies. To accurately image the salt, people need to integrate results of geomechanical models and stress-induced seismic velocity changes into the imaging approach. The results provide petroleum geologists with scientific insights into the link between near-salt stress perturbations and their induced seismic velocity changes and help exploration geophysicists build better seismic velocity models in salt basins and image salt accurately.

Objective assessments of players performance and individual characteristics are increasingly used in baseball. However, evidence linking individual characteristics to players' performance are scarce. The purpose of the study was to identify across ages, in younger males and females, and to compare, in younger males, the anthropometrics, athletic abilities and perceptual-cognitive skills associated with baseball pitcher's ball velocity. A cross-sectional design was used to conduct this study. Male and female athletes completed a sociodemographic questionnaire followed by anthropometric, athletic ability, perceptual-cognitive skill and pitching velocity assessments. Athletes were categorized by their age categories (11U, 13U, 15U, 18U, 21U). To evaluate the athletes' anthropometrics, height and weight, BMI, waist circumference, arms segmental length and girth were measured. Athletic abilities were assessed using athletes' grip strength, upper body power, vertical jump height, sprint, change of direction, and dynamic balance. Perceptual-cognitive skills performance was assessed with the Neurotracker platform. Pitching performance assessment was completed using the athletes' average fastball velocity. Kendall Tau's correlation coefficient was used to assess relationships between variables and pitching velocity in male athletes (p < 0.05). A 1-way ANOVA was performed to identify differences between age categories for all variables in male athletes (p < 0.05). In male athletes, without age categories discrimination, all anthropometric, athletic ability and perceptual-cognitive skill factors were associated with pitching velocity with associations ranging from τ = 0.185 for perceptual-cognitive skills to τ = 0.653 for left arm grip strength. The results showed that significant differences exist between age categories for anthropometric, athletic ability and perceptual-cognitive skill assessments. The study showed that associations between anthropometrics and pitching velocity, and athletic abilities and pitching velocity vary across age categories. Descriptive data of female athletes results regarding anthropometrics, athletic abilities, perceptual-cognitive skills and pitching velocity are also presented. Gender differences should be investigated in future studies exploring baseball pitching performance.

Taniyama, D, Matsuno, J, Yoshida, K, Pyle, B, and Nyland, J. Rotational medicine ball throw velocity relates to NCAA Division III college baseball player bat swing, batted baseball, and pitching velocity. J Strength Cond Res 35(12): 3414-3419, 2021-Previous studies have evaluated relationships between baseball batting or pitching and whole-body power tests such as rotational medicine ball throw velocity (RMBTV) (transverse plane), lateral-to-medial hop for distance (frontal plane), and two-legged standing broad jump for distance (sagittal plane). However, no previous report has evaluated all 3 whole-body power tests in the same study to determine their relationship to bat swing velocity or pitching velocity. The purpose of this descriptive study was to determine correlational relationship strength between bat swing velocity, batted baseball velocity, and throwing velocity with 2-legged standing broad jump for distance, lateral-to-medial jump for distance, and RMBTV whole-body power tests in collegiate baseball players. Thirty-five NCAA Division III players (15 pitchers and 23 hitters; 3 players played pitcher and other positions) participated in this study. An alpha value of p < 0.05 was selected to indicate statistical significance. Moderate relationships were observed between bat swing velocity and RMBTV (r = 0.65, p = 0.003), explaining 39% of the variance, and between pitching velocity and RMBTV (r = 0.62, p = 0.02), explaining 38% of the variance. A moderate correlation was also observed between batted baseball velocity and RMBTV (r = 0.53, p = 0.02), explaining 28% of the variance. Only the RMBTV whole-body power test displayed significant relationships with bat swing velocity, batted baseball velocity, and pitching velocity. Significant relationships were not identified for either the two-legged standing broad jump for distance or the lateral-to-medial jump for distance whole-body power tests and bat swing velocity or pitching velocity. Further studies should evaluate whether the coordination developed during RMBTV movements can decrease baseball shoulder and elbow injuries associated with repetitive, poorly timed, sequential lower extremity-trunk-upper extremity whole-body movements.

This investigation examined the adjustments made in cycle rate and length to velocity changes during roller skiing with the double pole (DP), kick double pole (KD), and VI skate (VS) techniques. Eight cross-country ski racers roller skied with each technique on a flat track at submaximal and maximal velocities while being videotaped from a lateral view. Increases in submaximal velocities were associated with increases in cycle rate and cycle length for KD and VS but only with increases in cycle rate for DP. Maximal sprint velocities were approximately 7% lower (p &lt; .01) for KD than for DP and VS and were associated with increases (p &lt; .01) in cycle rate for each technique combined with decreases (p &lt; .01) in cycle length for DP and VS. The findings indicate that there are differences among techniques in the manner in which cycle rate and length are adjusted to change submaximal velocity, but each technique relies upon an increase in cycle rate to achieve maximal velocity.

Severe obesity affects metabolism with potential to influence the lactate and glycemic response to different exercise intensities in untrained and trained rats. Here we evaluated metabolic thresholds and maximal aerobic capacity in rats with severe obesity and lean counterparts at pre- and post-training. Zucker rats (obese: n = 10, lean: n = 10) were submitted to constant treadmill bouts, to determine the maximal lactate steady state, and an incremental treadmill test, to determine the lactate threshold, glycemic threshold and maximal velocity at pre and post 8 weeks of treadmill training. Velocities of the lactate threshold and glycemic threshold agreed with the maximal lactate steady state velocity on most comparisons. The maximal lactate steady state velocity occurred at higher percentage of the maximal velocity in Zucker rats at pre-training than the percentage commonly reported and used for training prescription for other rat strains (i.e., 60%) (obese = 78 ± 9% and lean = 68 ± 5%, P < 0.05 vs. 60%). The maximal lactate steady state velocity and maximal velocity were lower in the obese group at pre-training (P < 0.05 vs. lean), increased in both groups at post-training (P < 0.05 vs. pre), but were still lower in the obese group at post-training (P < 0.05 vs. lean). Training-induced increase in maximal lactate steady state, lactate threshold and glycemic threshold velocities was similar between groups (P > 0.05), whereas increase in maximal velocity was greater in the obese group (P < 0.05 vs. lean). In conclusion, lactate threshold, glycemic threshold and maximal lactate steady state occurred at similar exercise intensity in Zucker rats at pre- and post-training. Severe obesity shifted metabolic thresholds to higher exercise intensity at pre-training, but did not attenuate submaximal and maximal aerobic training adaptations.

Objectives: The ulnar collateral ligament (UCL) is one of the most common sites of injury in baseball pitchers, with 25% of Major League Baseball (MLB) pitchers having undergone surgical reconstruction (UCLR). It remains unknown whether the ligament can respond to the stress of pitching. The purpose this study is to determine the response of the UCL in professional pitchers to pitching through a prospective ultrasonographic study. Methods: This was a prospective study supported by the Major League Baseball Research Committee. All pitchers within a single professional baseball club were enrolled. Pitching exposure history data including number of years pitching and peak pitch velocity were collected. A full ultrasound (US) examination of the ligament was then performed by a single fellowship-trained ultrasonographer with extensive experience with UCL US. This US examination was performed at the beginning of the season and then repeated at end of the season. This US examination included measurement of UCL thickness and valgus laxity, as measured via ulnotrochlear joint opening at 30° of flexion to valgus stress of 10% of the mean pitching torque of 64 Nm. Two US images were saved for each measurement such that all measurements were made twice and analysis was performed on the average. Thirty ultrasounds were measured by a second experienced ultrasonographer to determine inter-rater reliability via intra-class correlation coefficients (ICC). Correlation analyses were performed between pre-season data and pitching exposure data. Both paired and unpaired analyses compared pre- and post-season data. Results: 94 pitchers were included prior to the season and 83 were included at the completion of the season. With player movement in and out of the active roster, follow-up rate was 70% (46/66) of those available. These pitchers were 24±3 years old (mean±standard deviation), had 12±6 years pitching experience, and had peak velocity of 95±2 miles per hour. 13 pitchers (9%) had undergone UCLR prior to enrollment and 9 (6%) underwent UCLR after enrollment. With examination of US data, ICCs were 0.742 for UCL thickness and 0.878 and 0.871 for UCL laxity without and with stress at 30° respectively. Peak pitch velocity positively correlated with UCL thickness (ρ= 0.268, p=0.009) and valgus laxity at 30° (ρ= 0.266, p=0.010). In both paired and unpaired analyses, UCL thickness increased during the season (p=0.006 and 0.033 respectively). In the paired analysis valgus laxity at 30° increased non-significantly (p=0.069) and in the unpaired analysis, valgus laxity at 30° increased significantly (p=0.013). Conclusion: The ulnar collateral ligament responds to stress in professional pitchers. The UCL thickens and becomes more lax in response to higher pitch velocity and more years of pitching. The UCL thickens and valgus laxity increases with the stress of a single season of pitching. Our study will gather data on the same pitchers at the beginning of the next season to understand the healing response of the ligament to rest.

Major League Baseball pitch velocity and pitch type associated with risk of ulnar collateral ligament injury

Predictors of throwing velocity in youth and adolescent pitchers

Background:There are limited data on the performance or pitching metrics of Major League Baseball (MLB) pitchers who returned to play after ulnar collateral ligament reconstruction (UCLR).Purpose:To describe MLB pitcher performance after return from primary UCLR, compare the velocity and pitch characteristics against the preoperative season, and determine if performance analytics can predict successful return to pitching after UCLR.Study Design:Case-control study; Level of evidence, 3.Methods:This study included 63 pitchers who underwent primary UCLR between 2015 and 2019. Publicly available advanced analytics and pitch metrics from the first 2 postoperative seasons were compared with the preoperative (index) season as well as with an uninjured control group.Results:Overall, 57% of the pitchers successfully returned to the MLB level. Although they threw significantly fewer pitches (P = .012) and innings (P = .022) in postoperative year 1 as compared with the index season, there were no significant differences in pitch velocity, release extension, perceived velocity, or performance as measured by advanced analytics. Also, as compared with the index season, returners demonstrated increased postoperative spin rates on curveballs (P = .001) and sliders (P = .010), and curveball horizontal movement was significantly increased (P = .007); however, horizontal movement was significantly decreased for 4-seam fastballs (P = .026), changeups (P = .005), and sinkers (P = .019). The vertical movement on 4-seam fastballs was greater (P < .001) in postoperative year 1, and the vertical movement on curveballs (P = .031) and sinkers (P = .010) was greater in postoperative year 2 when compared with the index season. Pitchers who failed to return to the MLB level had a lower preoperative strikeout percentage (P = .047), fewer strikeouts per 9 innings pitched (P = .046), fewer wins above replacement ([WAR]; P = .026), and lower player value (P = .030) than the pitchers who returned.Conclusion:Pitchers returning to the MLB level after UCLR demonstrated changes in pitch movement profiles and spin rates postoperatively, but there were no differences in velocity or many advanced analytics upon return. Pitchers with lower strikeout metrics, fewer WAR, and less player value before surgery may have an elevated risk of failing to return to the MLB level.

Although coaches chart pitch velocity (PV) and strike percentage (SP) to assess pitcher fatigue levels, the validity of these tools has not been quantified in young pitchers. The purpose of this study was to compare PV and SP across levels of perceived fatigue in young pitchers. Data describing PV, first strike percentage (SP1st), total strike percentage (SPT) and perceived fatigue (PFL) throughout a simulated performance were recorded for 14 pitchers. Differences within PV, SP1st, and SPT were compared across PFLs utilizing repeated measures analysis of variance. PF was the independent variable and PV, SP1st, and SPT were the dependent variables. Results indicated no differences in PV across fatigue levels. SPT increased significantly from PFL 0 to PFL 1 (p = 0.0250). SP1st also increased significantly between PFL 0 and PFL 1 (p = 0.0040) before decreasing significantly for PFL 2 (p < 0.001). These results indicate that the tracking of PV may not be a valid tool for assessing fatigue. However, tracking both SP1st and SPT may be valid tools for assessing fatigue and may provide coaches with evidence of the onset of fatigue.