scholarly journals Effects of Game Pitch Count and Body Mass Index on Pitching Biomechanics in 9- to 10-Year-Old Baseball Athletes

2018 ◽  
Vol 6 (4) ◽  
pp. 232596711876565 ◽  
Author(s):  
Jim D. Darke ◽  
Eshan M. Dandekar ◽  
Arnel L. Aguinaldo ◽  
Scott J. Hazelwood ◽  
Stephen M. Klisch

Background: Pitching while fatigued and body composition may increase the injury risk in youth and adult pitchers. However, the relationships between game pitch count, biomechanics, and body composition have not been reported for a study group restricted to 9- to 10-year-old athletes. Hypothesis: During a simulated game with 9- to 10-year-old athletes, (1) participants will experience biomechanical signs of fatigue, and (2) shoulder and elbow kinetics will correlate with body mass index (BMI). Study Design: Descriptive laboratory study. Methods: Thirteen 9- to 10-year-old youth baseball players pitched a simulated game (75 pitches). Range of motion and muscular output tests were conducted before and after the simulated game to quantify fatigue. Kinematic parameters at foot contact, maximum external rotation, and maximum internal rotation velocity (MIRV), as well as maximum shoulder and elbow kinetics between foot contact and MIRV were compared at pitches 1-5, 34-38, and 71-75. Multivariate analyses of variance were used to test the first hypothesis, and linear regressions were used to test the second hypothesis. Results: MIRV increased from pitches 1-5 to 71-75 ( P = .007), and head flexion at MIRV decreased from pitches 1-5 to 34-38 ( P = .022). Maximum shoulder horizontal adduction, external rotation, and internal rotation torques increased from pitches 34-38 to 71-75 ( P = .031, .023, and .021, respectively). Shoulder compression force increased from pitches 1-5 to 71-75 ( P = .011). Correlations of joint torque/force with BMI were found at every pitch period: for example, shoulder internal rotation ( R2 = 0.93, P < .001) and elbow varus ( R2 = 0.57, P = .003) torques at pitches 1-5. Conclusion: Several results differed from those of previous studies with adult pitchers: (1) pitch speed remained steady, (2) shoulder MIRV increased, and (3) shoulder kinetics increased during a simulated game. The strong correlations between joint kinetics and BMI reinforce previous findings that select body composition measures may be correlated with pitching arm joint kinetics for youth baseball pitchers. Clinical Relevance: The results improve our understanding of pitching biomechanics for 9- to 10-year-old baseball pitchers and may be used in future studies to improve evidence-based injury prevention guidelines.

2005 ◽  
Vol 33 (11) ◽  
pp. 1716-1722 ◽  
Author(s):  
Michelle B. Sabick ◽  
Young-Kyu Kim ◽  
Michael R. Torry ◽  
Michael A. Keirns ◽  
Richard J. Hawkins

Background The effects of repetitive throwing on the shoulders of developing athletes are not well understood because of the paucity of data describing the biomechanics of youth pitchers and the plasticity of the developing skeleton. Hypothesis The direction and magnitude of the stresses that exist at the proximal humeral physis during the fastball pitching motion are consistent with the development of proximal humeral epiphysiolysis (Little League shoulder) and/or humeral retrotorsion. Study Design Descriptive laboratory study. Methods A total of 14 elite youth baseball pitchers (mean age, 12.1 ± 0.4 years) were filmed from the front and dominant side while throwing fastballs in a simulated game. The net force and torque acting on the humerus throughout the throwing motion were calculated using standard biomechanical techniques. Results The external rotation torque about the long axis of the humerus reached a peak value of 17.7 ± 3.5 N.m (2.7% ± 0.3% body weight × height) just before maximum shoulder external rotation. A shoulder distraction force of 214.7 ± 47.2 N (49.8% ± 8.3% body weight) occurred at, or just after, ball release. Conclusion Shear stress arising from the high torque late in the arm-cocking phase is large enough to lead to deformation of the weak proximal humeral epiphyseal cartilage, causing either humeral retrotorsion or proximal humeral epiphysiolysis over time. The stresses generated by the external rotation torque are much greater than those caused by distraction forces generated during the pitching motion of youth baseball pitchers. Clinical Relevance The motion of throwing fastballs by youth baseball pitchers results in force components consistent with proposed mechanisms for 2 clinical entities.


2018 ◽  
Vol 46 (9) ◽  
pp. 2148-2153 ◽  
Author(s):  
Kelechi R. Okoroha ◽  
Vincent A. Lizzio ◽  
Fabien Meta ◽  
Christopher S. Ahmad ◽  
Vasilios Moutzouros ◽  
...  

Background: There has been an increasing incidence of overuse elbow injuries among youth and adolescent pitchers. Pitch type has been implicated as a risk factor for excess torque at the medial elbow; however, this has not been definitively demonstrated. Purpose: To assess predictors of torque across the medial elbow in youth and adolescent pitchers with a mobile sensor. In addition, the authors aimed to determine the differences in elbow torque produced according to pitch type (fastball, curveball, changeup) and pitcher demographics. Study Design: Descriptive laboratory study. Methods: Twenty youth and adolescent pitchers were instructed to throw 8 fastballs, 8 curveballs, and 8 changeups in a standardized but randomized sequence over a 25-minute period. Five pitchers were evaluated each day. A sensor placed at the medial elbow reported elbow torque, arm speed, arm slot, and shoulder rotation for each pitch, while a radar gun measured peak ball velocity. The primary outcome was a determination of thrower and pitch characteristics associated with elevated torque across the medial elbow. Secondary outcomes included the evaluation of differences in throwing biomechanics among different pitch types. Outcomes were assessed via a multivariable model, which controlled for possible covariates. Results: In total, 20 youth baseball pitchers with a mean age of 14.1 years (range, 12-17 years) were included in the study. On average, fastballs caused the greatest torque across the medial elbow (least squares mean ± SE, 47.3 ± 0.5 N·m) as compared with changeups (44.2 ± 0.5 N·m; P < .001) and curveballs (45.0 ± 0.5 N·m; P = .002). However, curveballs produced the greatest arm speed (917.8 rpm). Pitchers who started throwing curveballs at an older age experienced less elbow torque ( P < .001). A multivariable model demonstrated that increased ball velocity and body mass index and decreased arm slot were independent predictors of increased elbow torque. Conversely, increasing age, longer arm length, and greater elbow circumference were independent protectors against elbow torque. Conclusion: This study found that among youth and adolescent pitchers, fastballs generate the highest elbow torque while curveballs generated the greatest arm speed. Increased ball velocity and body mass index and decreased arm slot were predictors of elbow torque; however, increasing age and size of a pitcher’s arm were protectors against elbow torque. These findings are important to better understand risk factors for overuse injury in this at-risk athletic population. Clinical Relevance: These findings may inform future pitching recommendations with intentions of curtailing medial elbow injuries experienced by young pitchers, such as ulnar collateral ligament injuries.


2020 ◽  
pp. 1-26
Author(s):  
Jéssica Cumpian Silva ◽  
Ana Elisa Madalena Rinaldi ◽  
Francisco de Assis Guedes Vasconcelos ◽  
Maria Alice Altenburg Assis ◽  
Camila Medeiros Mazzeti ◽  
...  

ABSTRACT Objective: Our study aimed to describe body phenotypes (BP) estimated by multivariate analysis and their association with body mass. Design: Body phenotypes were defined based on demographic variables, anthropometric data (body mass, height, skinfolds and circumferences), body composition (phase angle measured by bioelectrical impedance analysis), biochemical parameters (triglycerides, glucose, total cholesterol ratio/Low Density Lipoproteins (LDL), haemoglobin and sexual maturation (pubic hair and breasts or gonads). Analysis of variance (ANOVA) was performed to verify the differences between skin colour and the stages of pubertal development, body phenotypes, body composition, anthropometric, and biochemical variables. Setting: Cities of São Paulo-SP, Piracicaba-SP and Florianópolis-SC from Brazil and the United States. Participants: 9269 adolescents aged between 10 to 15 years old. Results: The composition of BP was similar in all surveys, which are: BP1 was composed by skinfolds, body mass and circumferences variables; BP2 by pubic hair, breast in girls or gonad in boys, height and age; BP3 by cholesterol, triglycerides and glucose; and BP4 by phase angle, haemoglobin and glucose (negative loading). There was a strong correlation (r = 0.9, p <0.001) between BP1 and body mass index. Conclusion: We highlighted independence observed between biochemical parameters, anthropometry, body composition and sexual maturation. BP may support the calculation of scores for diagnosis of obesity based on anthropometric variables and overcome ambiguity in the isolated use of body mass index.


2020 ◽  
pp. 1-17
Author(s):  
Ilana Eshriqui ◽  
Angélica Marques Martins Valente ◽  
Luciana Dias Folchetti ◽  
Bianca de Almeida-Pititto ◽  
Sandra Roberta G. Ferreira

Abstract Objective: To investigate the association between maternal pre-pregnancy body mass index (BMI) and offspring body composition in adulthood. Design: Retrospective cohort. Undergraduates of nutrition or nutritionists were recruited at the baseline of the Nutritionists’ Health Study between 2014 and 2017. Maternal pre-pregnancy BMI and current life aspects were self-reported through online questionnaires. Three body compartments were DXA-determined. The following variables were obtained: body-fat (%), fat mass index (FMI) (kg/m2), android-to-gynoid fat ratio, visceral adipose tissue (VAT) (cm3), appendicular skeletal muscle mass index (ASMI) (kg/m2), total bone and femur mineral content (g) and density (g/cm2). Linear regression adjusted according to directed acyclic graphs recommendation was performed. Setting: São Paulo, Brazil. Participants: Healthy non-pregnant women (aged 20-45 years) (n=150). Results: Median age and BMI were 22 years (IQR=20; 29) and 22.3 kg/m2 (IQR=20.4; 25.3). Pre-pregnancy BMI≥25 kg/m2 was reported by 14.7% of mothers. In fully adjusted models, maternal pre-pregnancy BMI was associated with their daughters’ body-fat % (β=0.31; 95%CI=0.0004; 0.63), FMI (β=0.17; 95%CI=0.03; 0.30, android-to-gynoid ratio (β=0.01; 95%CI=0.004; 0.02) and VAT (β=0.09; 95%CI=0.02; 0.16), but not with total bone density (β=0.001; 95%CI=-0.003; 0.006) and content (β=7.13; 95%CI=-4.19; 18.46). Direct association with ASMI was also detected, but lost statistical significance when participants whose mothers were underweight were excluded. Conclusions: Maternal pre-pregnancy body mass index was directly associated with offspring general and visceral adiposity but seem not to be associated with bone mass. Results reinforce importance of avoiding excess of maternal adiposity, as an attempt to break the vicious cycle of obesity transmission.


2020 ◽  
Vol 05 (01) ◽  
pp. E8-E13
Author(s):  
Kenzie B. Friesen ◽  
Adam W. Anz ◽  
Jeffrey R. Dugas ◽  
James R. Andrews ◽  
Gretchen D. Oliver

AbstractCurrently it is hypothesized that increased body mass index may contribute to overuse injuries. Thus, if hip or shoulder range of motion is affected by body mass index, pitchers may be placing additional stress on joints as they seek to pitch at maximal velocity. The purpose of this study was to examine if range of motion at the hips and shoulders were related to body mass index classification. A sample of 147 female softball pitchers (17.0±4.2 years; 167.6±11.8 cm; 70.6±17.5 kg; body mass index=24.8±4.7 kg/m2) participated. Bilateral hip and shoulder range of motion were assessed. Multivariate analysis of variance results indicated body mass index [Wilks’ Λ=0.742, F=1.722, p=0.014, η2=0.095] significantly affected range of motion of the shoulder and hip. Post hoc results indicated the underweight group had significantly more range of motion than the obese group in hip internal range of motion on both the throwing side (mean difference=12.39, p=0.005) and glove side (mean difference=11.98, p=0.004). Although body composition is not overly emphasized among softball pitchers, the current study reveals excess weight may inhibit proper mechanics. Coaches, athletic trainers, strength and conditioning personnel, and athletes should acknowledge the role that body composition can play in affecting pitch outcomes.


2021 ◽  
Vol 13 (16) ◽  
pp. 8775
Author(s):  
Laura Redondo-Flórez ◽  
Domingo Jesus Ramos-Campo ◽  
Vicente Javier Clemente-Suárez

The aim of the present study was to analyse body composition, anxiety, cardiovascular, and physical activity factors related with academic performance of school students as well as to analyse differences, by age, in these factors. We analysed in 266 primary school students’ (8.81 ± 1.62 years, range: 5–13 years) heart rate, anthropometric variables to calculate body mass index, physical activity performance, anxiety levels and academic results by the average of marks. Students were divided in two different groups, firstly by their lower or higher academic performance, and secondly by age. Results showed a negative correlation between academic performance and age, weight, body mass index and trait anxiety variables. Additionally, significant differences were found by age, presenting older students higher scores in body mass index and lower physical activity, trait anxiety, heart rate and academic performance values than younger students. Overweight and obesity may have a great impact in academic performance in children and we pointed out the necessity to establish programs related with healthy habits which include improvements in physical activity and nutrition behaviours with the objective to enhance children’s health general status, psychological profile, cognitive and motor development, and academic performance.


2020 ◽  
Vol 40 ◽  
pp. 550-551
Author(s):  
E. Cereda ◽  
F. Lobascio ◽  
S. Masi ◽  
S. Crotti ◽  
S. Cappello ◽  
...  

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