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Multidirectional ground reaction forces (GRFs) and jump tests within baseball pitchers provide insight into athletic ability and coordination to produce lower-body force and power. Lowerbody power is a biomechanical feature that denotes physiological capacity through dynamic and passive tissue stretch-shortening in transferring energy from the ground through the kinetic chain. Optimized lower-body power may lessen the magnitude of forces on the upper extremity. Insufficient lower-body power may create a greater risk of upper-body injury. Lower-body power and its relationship to ball velocity have been minimally investigated, yet some research points to a correlation between jumping ability and fastball velocity. Because pitching is unilateral, practitioners should consider unilateral jumps to determine the extent of bilateral asymmetry or stride to drive leg differences that can guide training to remediate deficiencies. The purposes of this brief review are to (a) examine factors that influence vertical jump performance among baseball players, (b) examine research on pitching multidirectional GRFs, and (c) examine literature concerning jump performances to baseball pitching performance. Collectively, this review can assist coaches and practitioners in lower-body power testing and training for baseball pitchers. [ABSTRACT FROM AUTHOR]

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 (Irl < 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. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is Available in the Text. Baseball and softball base running involve appropriate body position and maximal sprinting that may require curvilinear sprinting and subsequent changes of direction depending on the situational context. Traditionally, the pro-agility test has been used in baseball and softball to evaluate agility performance. When evaluating the specific tests that could be used to record change of direction speed (CODS) time in base running, it is advised to record not only the total time to complete the test but also to record the time to complete each running segment because this will provide greater information about the CODS strengths and weaknesses for each athlete. Furthermore, it is important to consider whether an additional test integrating curvilinear and CODS characteristics to simulate base running provides further objective data to evaluate base running ability. This article introduces a new field assessment called the Curvilinear Ability Test (CAT) that measures both curvilinear and CODS properties in base running. The CAT is believed to provide greater assessment value versus the pro-agility and 505 agility tests in evaluating base running ability. The video abstract is available as Supplemental Digital Content 1, http://links.lww.com/SCJ/A381. [ABSTRACT FROM AUTHOR]

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, η² = 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. [ABSTRACT FROM AUTHOR]

Beam, JR, and Szymanski, DJ. Validity of 2 skinfold calipers in estimating percent body fat of college-aged men and women. J Strength Cond Res 24(12): 3448-3456, 2010--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] = [+ or -] 6.4%BF) and women (95% LOA = [+ or -] 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 = [+ or -] 8.6%BF) and the women (LOA = [+ or -] 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. KEY WORDS dual-energy x-ray absorptiometry, body composition, bioelectrical impedance analysis

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 x wk-1, for 12 weeks with their normal game bat. Group 2 performed additional rotational and full-body medicine ball exercises 3 d x 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 [less than or equal to] 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. KEY WORDS bat speed, correlations, performance variables

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. WORDS baseball, bat speed, resistance training, overweighted training, underweighted training

Szymanski, D.J., J.S. McIntyre, J.M. Szymanski, J.M. Molloy, N. H. Madsen, and D.D. Pascoe. 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. J. Strength Cond. Res. 20(1):231-240. 2006.--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 [less than or equal to] 0.01) in linear BV, CV, and HV (m*[s.sup.-1] [+ or -] SD) after 12 weeks of training; however, there were no differences between the 2 groups. Both groups statistically increased wrist and forearm strength (p [less than or equal to] 0.05). Group 2 had statistically greater increases (p [less than or equal to] 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. KEY WORDS. bat speed, grip strength, strength, resistance training

The present article addresses issues within U.S. collegiate sport as it pertains to the physical preparation and health and well-being of intercollegiate athletes. Specifically, the sport coach is often perceived as "all knowing" about every facet of their sport when, in fact, they typically are not formally educated or well-trained in current methods of enhancing sport performance. Often strength and conditioning coaches, who may also be poorly trained, are tied directly (financially and administratively) to the sport coach--a situation which has led to a subservient role heavily influenced by the wishes of the sport coach. This has unfortunately resulted in the multidimensional well-being of the athlete clearly not being a primary objective in many programs. [ABSTRACT FROM AUTHOR]

This study examined the effect of 12 weeks of wrist and forearm training on male high school baseball players (mean age = 15.3 [+ or -] 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 [+ or -] 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 [+ or -] 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. KEY WORDS. athlete, grip strength, periodization, resistance training

The purpose of this article is to provide a practical framework for athletic administrators and senior coaches to use in evaluating a strength and conditioning coach (SCC) under their supervision. A formal objective evaluation process may improve training outcomes, prevent common troublesome issues in the field, increase accountability, and optimize organizational dynamics. Recommendations include planned, systematic, and documented observation of work performed, review of performance testing data, and developmental feedback meetings between the SCC and the supervisor. Some modification may be necessary for each sector of the field. However, the general themes may still be followed by supervisors. [ABSTRACT FROM AUTHOR]