Countermovement Jump and Momentum Generation Associations to Fastball Velocity Performance Among Division I Collegiate Pitchers.

ABSTRACT: Sakurai, M, Qiao, M, Szymanski, DJ, and Crotin, RL. Countermovement jump and momentum generation associations to fastball velocity performance among Division I collegiate pitchers. J Strength Cond Res 38(7): 1288-1294, 2024-The current study explored the relationships between countermovement jump (CMJ) profiles and baseball pitching performance. Nineteen Division I collegiate pitchers performed in-laboratory pitching and bilateral CMJs. Whole-body kinematics and ground reaction force were collected during both pitching and CMJ evaluations. Statistically significant correlations of concentric impulse and peak power in the CMJ test with fastball velocity were observed (r = 0.71 and 0.68). Concentric impulse in CMJ also showed a statistically significant correlation with linear momentum in the anterior-posterior direction during pitching (r = 0.68). Lean body mass and body mass showed statistically significant correlations with both of the 2 linear momentums during pitching (r = 0.71∼0.83), and concentric impulse in CMJ (r = 0.71 and 0.81). Pelvis and trunk pitching mechanics did not correlate with any of the CMJ variables at the statistically significant level, whereas the direction of the correlations varied (|r| < 0.45). Assessment of a baseball pitcher's CMJ should focus on concentric impulse and peak power because only these showed meaningful relationships with fastball velocity or momentum generation during pitching. An increase in lean body mass is also suggested to be able to generate more impulse and momentum. Baseball coaches, strength coaches, and clinicians are encouraged to include lower-body explosive training to enhance the force and power output capacity of baseball pitchers.

Exploratory Investigation Into the Impact of Bilateral and Unilateral Jump Characteristics on Ground Reaction Force Applications in Baseball Pitching.

ABSTRACT: Lis, R, Szymanski, DJ, Qiao, M, and Crotin, RL. An exploratory investigation into the impact of bilateral and unilateral jump characteristics on ground reaction force applications in baseball pitching. J Strength Cond Res 37(9): 1852-1859, 2023-Jump tests are effective, valid, and reliable in examining lower-body power that can influence ground reaction forces (GRFs) in baseball pitching. Relationships between drive and stride leg GRFs and fastball velocities while pitching from the wind-up and stretch were evaluated for performance influences across the following conditions: (a) lower-body GRFs from unilateral countermovement jumps (UCMJ) and bilateral countermovement jumps (BCMJ) and (b) BCMJ and drive and stride leg UCMJ height. Nineteen Division I collegiate baseball pitchers (age; 19.9 ± 1.5 years, height; 1.86 ± 0.06 m, body mass; 90.7 ± 13.8 kg) completed BCMJ and UCMJ tests and threw four-seam fastballs from a pitching mound with 2 embedded force plates. Three moderate associations ( r ≥ 0.47) were statistically significant ( p < 0.05) for BCMJ and UCMJ heights to pitching GRFs. Stride leg UCMJ height was significantly greater than drive leg UCMJ height, p < 0.01, η 2 = 0.34. Wind-up and stretch GRFs were statistically similar. Fastball velocities showed a statistically significant association that was moderately high with wind-up and stretch stride leg anterior-posterior GRFs ( r ≥ 0.65, p < 0.01). Collegiate pitchers jumped significantly higher with their stride leg, and the sum of vertical unilateral jump height of both legs was significantly greater (27%) than BCMJ height to indicate greater single-leg dominance in jumping. Although stride leg height was higher, improving stride leg jumping performance may be functionally more important in producing greater momentum into foot strike that has the potential to increase fastball velocity.

Combined Countermovement Jump Testing and Motion Analysis as the Future of Performance Assessment for Baseball Pitchers: A Narrative Review.

ABSTRACT: Sakurai, M, Szymanski, DJ, Qiao, M, and Crotin, RL. Combined countermovement jump testing and motion analysis as the future of performance assessment for baseball pitchers: a narrative review. J Strength Cond Res 37(6): 1327-1338, 2023-Whole-body kinematics and kinetics impact pitching performance, and when coordination of momentum transfer is impacted, throwing-related injury risks increase. Although correlations between overhead throwing velocity and lower-body power measured by jump tests have been reported by previous studies, further research is needed to identify these relationships to better understand pitching mechanics and the validity and application of jump tests for the assessment of baseball pitchers. This review communicates effective whole-body pitching mechanics, including throwing arm, trunk, and pelvis, and lower body, as well as discusses the applicability of strength and power field tests to deepen training insights in establishing more efficient motor patterns. If both lower-body power and coordination of momentum transfer are optimized, baseball pitchers may experience reduced throwing arm stress. The overarching insight to be gained from this review article is that high performance in baseball pitching is multifactorial, and attention to both strength and skill coaching is paramount. As a result, the intersection of lower-body power testing and biomechanical analysis can play an important role in uniting strength and conditioning professionals, clinicians, pitching coaches, and biomechanics experts to advance pitching performance and health in the sport of baseball.

Anthropometric Evaluation of First Round Draft Selections in Major League Baseball.

ABSTRACT: Crotin, RL, Conforti, CM, Szymanski, DJ, and Oseguera, J. Anthropometric Evaluation of first round draft selections in Major League Baseball. J Strength Cond Res 37(8): 1609-1615, 2023-Physical stature effects on future Major League Baseball (MLB) performance and player evaluation are not known among amateurs. Amateur athletes with greater stature were expected to perform at a higher MLB level, play first base or catcher, be drafted earlier, begin earlier MLB careers, and receive higher signing bonuses compared with lower stature players. Publicly available high-school amateur data on 319 first round player selections from 2005 to 2015 identified athletes' body mass, heights, and body mass index (BMI) to determine impacts on MLB Wins Above Replacement (WAR) ratings, draft selection number, signing bonuses, position, educational background, innings pitched, and plate appearances before making an MLB debut. Student t tests split sample data above and below the median to examine mean differences for body mass, height, and BMI, whereas one-way analysis of variance with Bonferroni correction calculated first round selection groups and positional differences in anthropometry at an a priori alpha level of p ≤ 0.05. First basemen and catchers had the highest BMI of all positions ( p < 0.05, d > 0.80), high-school signees had higher BMI than collegiate signees during high-school years ( p < 0.03, d > 0.05), the first 5 selections had higher BMI than the last 5 selections in the first round ( p < 0.05, d = 0.38), all with moderate-to-large effects. High-school pitchers with less body mass reached the MLB level in less innings than heavier pitchers ( p < 0.001, d = 0.62). No anthropometric differences were seen in player WAR ratings. Results indicate a scouting preference toward high-school athletes with greater BMI, yet high-school anthropometrics seem to not influence future MLB performance.

The Effect of Intermittent Vest Cooling on Thermoregulation and Cardiovascular Strain in Baseball Catchers.

Bishop, SH, Szymanski, DJ, Ryan, GA, Herron, RL, and Bishop, PA. The effect of intermittent vest cooling on thermoregulation and cardiovascular strain in baseball catchers. J Strength Cond Res 31(8): 2060-2065, 2017-Baseball catchers are exposed to multiple physiological challenges while playing outside during the spring and summer months, many of which deal with recovery and thermoregulation. The purpose of this study was to investigate the effect of intermittent cooling on core temperature, cardiovascular strain, exertion, and recovery during a simulated catching performance in the heat. Six trained college-aged baseball catchers performed in a controlled, hot (35° C), and humid (25% relative humidity) environment in a counter-balanced, cross-over design. Ice vest cooling (VC) was used as a cooling modality and was compared with a control of no cooling (NC). Rectal temperature (Tre), heart rate (HR), rating of perceived exertion (RPE), and perceived recovery scale (PRS) were recorded before and after each simulated inning. All activities took place in a heat chamber, and each inning consisted of catchers receiving 12 pitches in their position followed by 6 minutes of recovery. Nine total innings were performed, and 27 total innings were performed with each of the 2 treatments. A significantly smaller mean Tre change was seen in VC when compared with NC (0.58 ± 0.2° C, 0.98 ± 0.2° C, p ≤ 0.01, respectively). Rating of perceived exertion was significantly lower and PRS was significantly improved for VC compared with NC (both p ≤ 0.05). Mean recovery HR during VC was significantly lower than NC in the fifth (VC = 84 ± 8 b·min, NC = 90 ± 9 b·min, p = 0.04), seventh (VC = 84 ± 3 b·min, NC = 92 ± 7 b·min, p = 0.02), and ninth (VC = 85 ± 7 b·min, NC = 93 ± 5 b·min, p = 0.01) innings. Heart rate during catching was significantly lower at the end of the VC trials when compared with NC (108 ± 16 b·min vs. 120 ± 19 b·min, p = 0.02, respectively). Vest cooling decreased heat strain, cardiovascular strain, and RPE while it improved perceived recovery in catchers over a simulated 3-game series performed in hot conditions.

Effects of Three Recovery Protocols on Range of Motion, Heart Rate, Rating of Perceived Exertion, and Blood Lactate in Baseball Pitchers During a Simulated Game.

Baseball pitching has been described as an anaerobic activity from a bioenergetics standpoint with short bouts of recovery. Depending on the physical conditioning and muscle fiber composition of the pitcher as well as the number of pitches thrown per inning and per game, there is the possibility of pitchers fatiguing during a game, which could lead to a decrease in pitching performance. Therefore, the purpose of this study was to evaluate the effects of 3 recovery protocols: passive recovery, active recovery (AR), and electrical muscle stimulation (EMS) on range of motion (ROM), heart rate (HR), rating of perceived exertion (RPE), and blood lactate concentration in baseball pitchers during a simulated game. Twenty-one Division I intercollegiate baseball pitchers (age = 20.4 ± 1.4 years; height = 185.9 ± 8.4 cm; weight = 86.5 ± 8.9 kg; percent body fat = 11.2 ± 2.6) volunteered to pitch 3 simulated 5-inning games, with a maximum of 70 fastballs thrown per game while wearing an HR monitor. Range of motion was measured pre, post, and 24 hours postpitching for shoulder internal and external rotation at 90° and elbow flexion and extension. Heart rate was recorded after each pitch and after every 30 seconds of the 6-minute recovery period. Rating of perceived exertion was recorded after the last pitch of each inning and after completing each 6-minute recovery period. Immediately after throwing the last pitch of each inning, postpitching blood lactate concentration (PPLa-) was measured. At the end of the 6-minute recovery period, before the next inning started, postrecovery blood lactate concentration (PRLa-) was measured. Pitchers were instructed to throw each pitch at or above 95% of their best-pitched fastball. This was enforced to ensure that each pitcher was throwing close to maximal effort for all 3 simulated games. All data presented represent group mean values. Results revealed that the method of recovery protocol did not significantly influence ROM (p > 0.05); however, it did significantly influence blood lactate concentration (p < 0.001), HR (p < 0.001), and RPE (p = 0.01). Blood lactate concentration significantly decreased from postpitching to postrecovery in the EMS recovery condition (p < 0.001), but did not change for either the active (p = 0.04) or the passive (p = 0.684) recovery conditions. Rating of perceived exertion decreased from the postpitching to postrecovery in both the passive and EMS recovery methods (p < 0.001), but did not decrease for AR (p = 0.067). Heart rate decreased for all conditions from postpitching to postrecovery (p < 0.001). The use of EMS was the most effective method at reducing blood lactate concentration after 6 minutes of recovery during a simulated game (controlled setting). Although EMS significantly reduced blood lactate concentrations after recovery, blood lactate concentrations after pitching in the simulated games were never high enough to cause skeletal muscle fatigue and decrease pitching velocity. If a pitcher were to throw more than 14 pitches per inning, throw more total pitches than normal per game, and have blood lactate concentrations increase higher than in the simulated games in this study, the EMS recovery protocol may be beneficial to pitching performance by aiding recovery. This could potentially reduce some injuries associated with skeletal muscle fatigue during pitching, may allow a pitcher throw more pitches per game, and may reduce the number of days between pitching appearances.

Effect of various warm-up devices on bat velocity of intercollegiate softball players.

Numerous warm-up devices are available for use by softball players while they are in the on-deck circle. It is difficult to know which warm-up device produces the greatest bat velocity (BV) in the batter's box for softball players because on-deck studies with these individuals are sparse. Because the majority of warm-up device research has been conducted with baseball players, the primary purpose of this study was to examine the effect of various warm-up devices on the BV of female intercollegiate softball players and compare the results with those of male baseball players. A secondary purpose was to evaluate 2 new commercially available resistance devices as warm-up aids. Nineteen Division I intercollegiate softball players (age = 19.8 ± 1.2 years, height = 167.0 ± 4.7 cm, body mass = 69.2 ± 8.6 kg, lean body mass = 49.6 ± 3.6 kg, % body fat = 27.9 ± 5.9) participated in a warm-up with 1 of 8 resistance devices on separate days. Each of the 8 testing sessions had players perform a standardized dynamic warm-up, 3 maximal dry swings mimicking their normal game swing with the assigned warm-up device, 2 comfortable dry swings with a standard 83.8-cm, 652-g (33-in., 23-oz) softball bat followed by 3 maximal game swings (20-second rest between swings) while hitting a softball off a batting tee with the same standard softball bat. Results indicated that there were no statistically significant differences in BV after using any of the 8 warm-up devices (510.3-2,721.5 g or 18-96 oz) similar to in previous baseball research. This indicates that the results for both male and female intercollegiate players are similar and that intercollegiate softball players can use any of the 8 warm-up devices in the on-deck circle and have similar BVs. However, similar to in other previous baseball research, it is not recommended that female intercollegiate softball players warm up with the popular commercial donut ring in the on-deck circle because it produced the slowest BV.

Effects of various warm-up devices and rest period lengths on batting velocity and acceleration of intercollegiate baseball players.

It is common among competitive baseball players to swing bats while in the batter's box in an attempt to improve their batting performance. Players use bats of different weights during this time, and only a few studies have evaluated the optimal bat weight to increase performance. Previous studies have not investigated the optimal rest period after a warm-up with bats of varying weights. Therefore, we tested the peak bat velocity of 16 National Collegiate Athletic Association Division II intercollegiate baseball players at 1, 2, 4, and 8 minutes, after warming up with bats of 5 different weights. Measured variables were peak bat velocity at peak acceleration (PVPA), peak bat velocity of the swing (PV), peak bat acceleration (PA), and time to reach peak acceleration (TPA) using a chronograph, which measured the batting velocity in real time every 10 milliseconds throughout the swing. A repeated measure analysis of variance was run to assess group, time, and group by time interactions. If any main effects were found, a Tukey post hoc was employed to locate differences. There were significant (p ≤ 0.05) time effects for PVPA, PV, and PA but not for TPA. The PVPA, PV, and PA all increased over time, peaking from 4 to 8 minutes. There were no significant differences in any of the variables among the 5 bat weights used in the warm-up (p > 0.05). However, there were significant differences in PVPA, PV, and PA after 2, 4, and 8 minutes of rest compared with the preexperimental warm-up and 1-minute post-warm-up. From a practical standpoint, batters should warm up early and quickly in the batter's box to maximize the amount of recovery time before they swing at the plate. In addition, batters may want to take their time getting ready at the plate or take some pitches while at-bat in an attempt to maximize performance. Alternatively, the data imply that pitchers should throw their fastest pitch near the beginning of the at-bat to correspond with the potentially slower bat speeds of the batter.

Effect of various warm-up devices on bat velocity of intercollegiate baseball players.

A variety of warm-up devices are available to baseball players to use before their game at-bat. Past baseball research evaluating warm-up devices indicates that implements that are ±12% of standard game bat weight produce the greatest bat velocities for high school and intercollegiate players. The purpose of this study was to examine the effect of various warm-up devices on bat velocity (BV) of intercollegiate baseball players. Twenty-two Division I intercollegiate baseball players (age = 20.0 ± 1.5 years, height = 182.6 ± 8.3 cm, body mass = 91.4 ± 11.4 kg, lean body mass = 78.8 ± 8.9 kg, % body fat = 13.6 ± 3.8) participated in a warm-up with 1 of 10 weighted devices on separate days. Each of the 10 testing sessions consisted of a standardized warm-up, 3 dry swings as hard as possible with the assigned warm-up device, 2 comfortable dry swings with a standard game baseball bat followed by 3 game swings (20-second rest between swings) while hitting a baseball off of a batting tee with the same standard game baseball bat. Results indicated that there were no statistically significant differences in BV after using any of the 10 warm-up devices. For male intercollegiate baseball players, results indicate that warm-up devices varying from 623.7 to 2,721.5 g (22-96 oz.) did not change mean BV of a standard game baseball bat, suggesting that intercollegiate players can use any of the 10 warm-up devices in the on-deck circle and maintain their BV. Therefore, personal preference as to which warm-up implement to use in the on-deck circle is advised.

The relation between anthropometric and physiological variables and bat velocity of high-school baseball players before and after 12 weeks of training.

The purpose of this article was to investigate the relation between anthropometric and physiological variables to linear bat swing velocity (BV) of 2 groups of high-school baseball players before and after completing a 12-week periodized resistance exercise program. Participants were randomly assigned to 1 of 2 training groups using a stratified sampling technique. Group 1 (n = 24) and group 2 (n = 25) both performed a stepwise periodized resistance exercise program and took 100 swings a day, 3 d·wk-1, for 12 weeks with their normal game bat. Group 2 performed additional rotational and full-body medicine ball exercises 3 d·wk-1 for 12 weeks. Fourteen variables were measured or calculated before and after 12 weeks of training. Anthropometric and physiological variables tested were height, body mass, percent body fat, lean body mass (LBM), dominant torso rotational strength (DTRS) and nondominant torso rotational strength (NDTRS), sequential hip-torso-arm rotational strength measured by a medicine ball hitter's throw (MBHT), estimated 1 repetition maximum parallel squat (PS) and bench press (BP), vertical jump (VJ), estimated peak power, angular hip velocity (AHV), and angular shoulder velocity (ASV). The baseball-specific skill of linear BV was also measured. Statistical analysis indicated a significant moderately high positive relationship (p ≤ 0.05) between prelinear BV and pre-NDTRS for group 1, pre-LBM, DTRS, NDTRS, peak power, and ASV for group 2; moderate positive relationship between prelinear BV and preheight, LBM, DTRS, peak power, BP, PS, and ASV for group 1, preheight, body mass, MBHT, BP, and PS for group 2. Significantly high positive relationships were indicated between postlinear BV and post-NDTRS for group 1, post-DTRS and NDTRS for group 2; moderately high positive relationships between postlinear BV and post-LBM, DTRS, peak power, BP, and PS for group 1, postheight, LBM, VJ, peak power for group 2; moderate positive relationships between postlinear BV and postheight, body mass, MBHT, and VJ for group 1, postbody mass, MBHT, BP, PS, and ASV for group 2. Significantly low positive relationships were indicated between prelinear BV and prebody mass, MBHT, and VJ for group 1, pre-VJ and AHV for group 2; postlinear BV and post-AHV for group 2. These data show that significant relationships do exist between height, body mass, LBM, rotational power, rotational strength, lower body power, upper and lower body strength, AHV, and ASV to linear BV of high-school baseball players. Strength coaches may want to consider using this information when designing a resistance training program for high-school baseball players. Those recruiting or scouting baseball players may want to use this information to further develop ways of identifying talented players. However, one should be cautious when interpreting this information when designing strength training programs for high-school baseball players to increase linear BV.

Validity of 2 skinfold calipers in estimating percent body fat of college-aged men and women.

There is a need for cost-effective techniques that accurately predict percent body fat (%BF) and require little skill to administer. There are 2 commercially available skinfold calipers, 1 digital and the other self-administered, that claim to accurately predict %BF. The primary purpose of this study was to validate these calipers using dual-energy x-ray absorptiometry (DXA) as a reference method in a sample of college-aged men and women. A secondary purpose of this study was to compare the validity of these calipers to the validity of arm-to-arm bioempedance analysis (BIA) (Omron, Shelton, Connecticut, U.S.A.), leg-to-leg BIA (Tanita, Arlington Heights, Illinois, U.S.A.), and 3-site skinfold equations (SUM3) using DXA as a reference method. Fifty college students (25 men and 25 women) from a kinesiology department who ranged in fitness levels volunteered to have %BF measured by the digital and self-administered skinfold calipers, Omron, Tanita, and SUM3. The digital and self-administered skinfold calipers had the poorest group predictive accuracy for the men and women (total error ranged from 7.9 to 10.9%BF) when compared to the other field methods. The digital skinfold caliper had good individual predictive accuracy in the men (95% limits of agreement [LOA] = ± 6.4%BF) and women (95% LOA = ± 4.9%BF) when compared to the other field methods. However, the self-administered skinfold caliper had poor individual predictive accuracy for the men (LOA = ± 8.6%BF) and the women (LOA = ± 7.5%BF) when compared to the other field methods. Compared to DXA, Tanita, Omron, and SUM3, we would not recommend using the digital or self-administered skinfold calipers for estimating %BF in college-aged men and women with similar body composition as the men and women in this study. We recommend using the SUM3 to estimate %BF.

Contributing factors for increased bat swing velocity.

Bat swing velocity is an important characteristic of successful hitters in baseball and softball. The purpose of this literature review is threefold. First, before describing what components and training methods have been investigated to improve bat swing velocity, it is necessary to discuss the importance of bat swing velocity and batted-ball velocity. The second purpose is to discuss bat weight during on-deck circle warm-up, bat weight during resistance training, resistance training with an overload of force, performance of additional supplemental resistance exercises, the relationship between strength, power, lean body mass, and angular velocity and bat swing velocity, and the relationship between improvements in strength, power, lean body mass, and angular velocity and improvements in bat swing velocity. The third purpose of this review is to recommend some practical applications based on research results.

Effect of torso rotational strength on angular hip, angular shoulder, and linear bat velocities of high school baseball players.

This investigation examined the effect of torso rotational strength on angular hip (AHV), angular shoulder (ASV), linear bat-end (BEV), and hand velocities (HV) and 3 repetition maximum (RM) torso rotational and sequential hip-torso-arm rotational strength (medicine ball hitter's throw) in high school baseball players (age 15.4 +/- 1.2 y). Participants were randomly assigned to 1 of 2 training groups. Group 1 (n = 24) and group 2 (n = 25) both performed a stepwise periodized resistance exercise program and took 100 swings a day, 3 days a week, for 12 weeks with their normal game bat. Group 2 performed additional rotational and full-body medicine ball exercises 3 days a week for 12 weeks. A 3RM parallel squat and bench press were measured at 0 and after 4, 8, and 12 weeks. Participants were pre- and posttested for 3RM dominant and nondominant torso rotational strength and medicine ball hitter's throw. Angular hip velocities, ASV, BEV, and HV were recorded pre- and posttraining by a motion capture system that identified and digitally processed reflective markers attached to each participant's bat and body. Groups 1 and 2 increased (p < or = 0.05) BEV (3.6 and 6.4%), HV (2.6 and 3.6%), 3RM dominant (10.5 and 17.1%) and nondominant (10.2 and 18.3%) torso rotational strength, and medicine ball hitter's throw (3.0 and 10.6%) after 12 weeks. Group 2 increased AHV (6.8%) and ASV (8.8%). Group 2 showed greater improvements in BEV, AHV, ASV, 3RM dominant and nondominant torso rotational strength, and medicine ball hitter's throw than group 1. Groups 1 and 2 increased predicted 1RM parallel squat (29.7 and 26.7%) and bench press (17.2 and 16.7%) strength after 12 weeks. These data indicate that performing additional rotational medicine ball exercises 2 days a week for 12 weeks statistically improves baseball performance variables.

Effect of twelve weeks of medicine ball training on high school baseball players.

This study examined the effect of 12 weeks of medicine ball training on high school baseball players. Forty-nine baseball players (age 15.4 +/- 1.2 years) were randomly assigned using a stratified sampling technique to 1 of 2 groups. Group 1 (n = 24) and group 2 (n = 25) performed the same full-body resistance exercises according to a stepwise periodized model and took 100 bat swings a day, 3 days per week, with their normal game bat for 12 weeks. Group 2 performed additional rotational and full-body medicine ball exercises 3 days per week for 12 weeks. Pre- and post-testing consisted of a 3 repetition maximum (RM) dominant and nondominant torso rotational strength and sequential hip-torso-arm rotational strength (medicine ball hitter's throw). A 3RM parallel squat and bench press were measured at 0 and after 4, 8, and 12 weeks of training. Although both groups made statistically significant increases (p < or = 0.05) in dominant (10.5 vs. 17.1%) and nondominant (10.2 vs. 18.3%) torso rotational strength and the medicine ball hitter's throw (3.0 vs. 10.6%), group 2 showed significantly greater increases in all 3 variables than group 1. Furthermore, both groups made significant increases in predicted 1RM parallel squat and bench press after 4, 8, and 12 weeks of training; however, there were no differences between groups. These data indicate that performing a 12-week medicine ball training program in addition to a stepwise periodized resistance training program with bat swings provided greater sport-specific training improvements in torso rotational and sequential hip-torso-arm rotational strength for high school baseball players.

Effect of wrist and forearm training on linear bat-end, center of percussion, and hand velocities and on time to ball contact of high school baseball players.

This study examined the effects of 12 weeks of wrist and forearm training on linear bat-end velocity (BV), center of percussion velocity (CV), hand velocity (HV), and time to ball contact of high school baseball players. Forty-three baseball players were randomly assigned by a stratified sampling technique to 1 of 2 training groups. Group 1 (n = 23) and group 2 (n = 20) performed the same full-body resistance exercises while training 3 days a week for 12 weeks according to a stepwise periodized model. Group 2 also performed wrist and forearm exercises 3 days a week for 12 weeks. Wrist and forearm strength were measured pre- and posttraining. Linear BV, CV, HV, and time to ball contact were recorded pre- and posttraining by a motion-capture system. A 3 repetition maximum (RM) parallel squat and bench press were measured at baseline and after 4, 8, and 12 weeks of training. Both groups showed statistically significant increases (p < or = 0.01) in linear BV, CV, and HV (m.s(-1) +/- SD) after 12 weeks of training; however, there were no differences between the 2 groups. Both groups statistically increased wrist and forearm strength (p < or = 0.05). Group 2 had statistically greater increases (p < or = 0.05) in 10 of 12 wrist and forearm strength measures than did group 1. Both groups made statistically significant increases in predicted 1RM parallel squat and bench press after 4, 8, and 12 weeks of training; however, there were no differences between groups. These data indicate that a 12-week stepwise periodized training program can significantly increase wrist and forearm strength, linear BV, CV, and HV among high school baseball players. However, increased wrist and forearm strength did not contribute to further increases in linear BV, CV, or HV.

Effect of 12 weeks of wrist and forearm training on high school baseball players.

This study examined the effect of 12 weeks of wrist and forearm training on male high school baseball players (mean age = 15.3 +/- 1.1 years). Participants (N = 43) were tested for 10 repetition maximum (RM) wrist barbell flexion, wrist barbell extension, dominant (D) and nondominant (ND) hand-forearm supination, D and ND forearm pronation, D and ND wrist radial deviation, D and ND wrist ulnar deviation, D and ND grip strength, and a 3RM parallel squat (PS) and bench press (BP). Group 1 (n = 23) and group 2 (n = 20), randomly assigned by a stratified sampling technique, performed the same resistance exercises while training 3 days a week for 12 weeks according to a stepwise periodized model. Group 2 also performed wrist and forearm exercises 3 days a week for 12 weeks to determine if additional wrist and forearm training provided further wrist and forearm strength improvements. All wrist and forearm strength variables were measured before and after 12 weeks of training. The 3RM PS and BP were measured at 0 and after 4, 8, and 12 weeks of training. Both groups significantly increased wrist and forearm strength (kg +/- SD) except 10RM D and ND forearm supination for group 1 (p < 0.05). Group 2 showed statistically greater improvements (p < 0.05) in all wrist and forearm strength variables than did group 1 except for D and ND grip strength. Predicted 1RM (kg +/- SD) PS and BP increased significantly (p < 0.05) after weeks 4, 8, and 12 for both groups. These data indicate that a 12-week stepwise periodized training program can significantly increase wrist, forearm, PS, and BP strength for both groups. Additionally, group 2 had further wrist and forearm strength gains.