Effects of a Simulated Game on Upper Extremity Pitching Mechanics and Muscle Activations Among Various Pitch Types in Youth Baseball Pitchers.

BACKGROUND: Throwing requires proper stability and orientation of the pelvis and scapula for efficient energy transfer during pitching. Fatigue of the pelvis and scapular musculature throughout the course of a game can impair pitching performance, and place excessive demands on the throwing arm leading to injury. The purpose of this study was to examine differences in pelvis, torso, and upper extremity pitching mechanics and muscle activations between the fastball, change-up, and curveball pitches in youth baseball pitchers following a simulated game. METHODS: Fourteen youth baseball pitchers with no history of injury participated. Pitching mechanics were collected using an electromagnetic tracking system. Surface electromyography data were collected on the bilateral gluteus medius and maximus; and throwing arm side latissimus dorsi, lower trapezius, upper trapezius, and serratus anterior. Participants were instructed to throw maximum effort pitches during a simulated game that provided random game situations similar to those that occur in competition. Participants were limited to 85 pitches based on age-restricted pitch counts. Data from 3 fastballs, curveballs, and change-ups thrown in the first and last innings were selected for analysis. RESULTS: Repeated measures multivariate analyses of variance revealed that neither pitch type nor the effect of a simulated game resulted in statistically significant changes in pitching mechanics (F(10,600)=0.55, P=0.85), or muscle activations (pelvic: F(4,195)=0.07, P=0.85; scapular: F(4,118)=0.09, P=0.52). CONCLUSIONS: The principle findings of this study revealed that pitching to the age-restricted pitch count limit did not result in altered pitching mechanics or muscle activations, and no differences occurred between the 3 pitches. These results support previous research that indicate the curveball pitch is no more dangerous for youth than the other pitches commonly thrown. This is supported by the pitcher's ability to maintain a proper arm slot during all 3 pitches and indicates that they are obtaining the spin on the ball from their grip and not by altering upper extremity mechanics. LEVEL OF EVIDENCE: Level 5.

Effects of Game Performance on Softball Pitchers and Catchers.

Oliver, GD, Plummer, HA, Washington, JK, Weimar, WH, and Brambeck, A. Effects of game performance on softball pitchers and catchers. J Strength Cond Res 33(2): 466-473, 2019-The purpose of this study was to examine the effects of game exposure on pitchers and catchers' hip and glenohumeral range of motion (ROM), isometric strength, and vertical jump performance and power. Five college female softball pitchers (174.24 ± 7.53 cm; 82.10 ± 11.27 kg; 20 ± 1.82 years) and 4 catchers (165.10 ± 9.04 kg; 68.61 ± 3.87 cm; 20 ± 1.41 years) participated. Hip and glenohumeral rotational ROM; hip and glenohumeral rotational isometric strength; hip abduction and adduction strength; and vertical jump height were assessed pre- and postgame exposure. The catchers displayed significantly greater throwing side hip internal rotation (IR) ROM (mean difference = +6.88°, p = 0.03) postgame exposure, whereas the pitchers exhibited less IR (mean difference = -2.02%, p = 0.013) and external rotation (ER; mean difference = -1.95%, p = 0.026) strength in the nonthrowing side hip pre vs. postgame exposure. The performance demands of pitchers and catchers vary greatly, causing position-specific decreases/increases in various tests following game performance. Pitchers exhibited significant decreases in nonthrowing side hip IR and ER strength. In catchers, throwing side hip IR ROM significantly increased following game exposure. Further evaluation of ROM, strength, and power is necessary as it is unknown how these changes following a game affect sports performance or risk of injury.

HIP AND GLENOHUMERAL PASSIVE RANGE OF MOTION IN COLLEGIATE SOFTBALL PLAYERS.

BACKGROUND AND PURPOSE: Range of motion deficits at the hip and glenohumeral joint (GHJ) may contribute to the incidence of injury in softball players. With injury in softball players on the rise, softball related studies in the literature are important. The purpose of this study was to examine hip and GHJ passive range of motion (PROM) patterns in collegiate softball players. HYPOTHESIS: It was hypothesized that the position players would exhibit significantly different PROM patterns than pitchers. Additionally, position players would exhibit significantly different side-to-side differences in PROM for both the hip and GHJ compared to pitchers. STUDY DESIGN: Prospective cohort study. METHODS: Forty-nine collegiate softball players (19.63 ± 1.15 years; 170.88 ± 8.08 cm; 72.96 ± 19.41 kg) participated. Passive hip and GHJ internal (IR) and external rotation (ER) measures were assessed. Glenohumeral PROM was measured with the participants supine with the arm abducted to 90 °. The measurements were recorded when the scapula began to move or a firm capsular end-feel was achieved. The hip was positioned in 90 ° of flexion and passively rotated until a capsular end-feel was achieved. Total PROM was calculated by taking the sum of IR and ER for both the hip and GHJ. RESULTS: No significant side-to-side PROM differences were observed in pitchers, at the GHJ or hip joint. Position players throwing side hip IR was significantly greater than the non-throwing side hip (p = 0.002). The non-throwing side hip had significantly greater ER compared to the throwing side hip (p = 0.002). When examining side-to-side differences at the GHJ, IR was significantly greater in the non-throwing shoulder (p = 0.047). No significant differences in total range of motion of the hip and GHJ were observed. CONCLUSION: In the current study, position players displayed side-to-side differences in hip and GHJ IR PROM while no statistically significant differences were observed in the softball pitchers. The findings of the current study add to the body of literature related to PROM in throwing athletes, additionally these are the first hip IR and ER PROM data presented in softball players. LEVEL OF EVIDENCE: Level 3.