scholarly journals Fastball Velocity and Elbow-Varus Torque in Professional Baseball Pitchers

2019 ◽  
Vol 54 (3) ◽  
pp. 296-301 ◽  
Author(s):  
Jonathan S. Slowik ◽  
Kyle T. Aune ◽  
Alek Z. Diffendaffer ◽  
E. Lyle Cain ◽  
Jeffrey R. Dugas ◽  
...  

ContextHigh loads in the elbow during baseball pitching can lead to serious injuries, including injuries to the ulnar collateral ligament. These injuries have substantial implications for individual pitchers and their teams, especially at the professional level of competition. With a trend toward increased ball velocity in professional baseball, controversy still exists regarding the strength of the relationship between ball velocity and elbow-varus torque.ObjectiveTo examine the relationship between fastball velocity and elbow-varus torque in professional pitchers using between- and within-subjects statistical analyses.DesignCross-sectional study.SettingMotion-analysis laboratory.Patients or Other ParticipantsUsing the previously collected biomechanical data of 452 professional baseball pitchers, we performed a retrospective analysis of the 64 pitchers (52 right-hand dominant, 12 left-hand dominant; age = 21.8 ± 2.0 years, height = 1.90 ± 0.05 m, mass = 94.6 ± 7.8 kg) with fastball velocity distributions that enabled between- and within-subjects statistical analyses.Main Outcome Measure(s)We measured ball velocity using a radar gun and 3-dimensional motion data using a 12-camera automated motion-capture system sampling at 240 Hz. We calculated elbow-varus torque using inverse-dynamics techniques and then analyzed the relationship between ball velocity and elbow torque using both a simple linear regression model and a mixed linear model with random intercepts.ResultsThe between-subjects analyses displayed a weak positive association between ball velocity and elbow-varus torque (R2 = 0.076, P = .03). The within-subjects analyses showed a considerably stronger positive association (R2 = 0.957, P < .001).ConclusionsWhen comparing 2 professional baseball pitchers, higher velocity may not necessarily indicate higher elbow-varus torque due to the confounding effects of pitcher-specific differences (eg, detailed anthropometrics and pitching mechanics). However, within an individual pitcher, higher ball velocity was strongly associated with higher elbow-varus torque.

2020 ◽  
Vol 3 (3) ◽  
pp. 76-87
Author(s):  
Muhammad Naeem ◽  
Abdul Sami

The present study was an examination of the relationship between product brand loyalty and purchase decision of automotive customers. The study focused on comparative analysis of two famous brands of automobile i-e Honda City and Toyota Corolla Xli and the various effects of product brand loyalty on purchase decision of automotive customers. A cross sectional quantitative research design was employed in the research study. In today’s competitive business world, now most of the marketers and manufacturers of various brands have encountered with multiple variables through which they can not only influence the purchase decision of their customers but also secure their buying preferences. The variables that are used and relevant to this study are product brand loyalty, perceived quality, price, and purchase decision. During examination of the relationship between these variables, study investigated that there is a positive association between product brand loyalty, product perceived quality, price and purchase decision.


2021 ◽  
Vol 10 (6) ◽  
pp. 1211
Author(s):  
Li-Te Lin ◽  
Kuan-Hao Tsui

The relationship between serum dehydroepiandrosterone sulphate (DHEA-S) and anti-Mullerian hormone (AMH) levels has not been fully established. Therefore, we performed a large-scale cross-sectional study to investigate the association between serum DHEA-S and AMH levels. The study included a total of 2155 infertile women aged 20 to 46 years who were divided into four quartile groups (Q1 to Q4) based on serum DHEA-S levels. We found that there was a weak positive association between serum DHEA-S and AMH levels in infertile women (r = 0.190, p < 0.001). After adjusting for potential confounders, serum DHEA-S levels positively correlated with serum AMH levels in infertile women (β = 0.103, p < 0.001). Infertile women in the highest DHEA-S quartile category (Q4) showed significantly higher serum AMH levels (p < 0.001) compared with women in the lowest DHEA-S quartile category (Q1). The serum AMH levels significantly increased across increasing DHEA-S quartile categories in infertile women (p = 0.014) using generalized linear models after adjustment for potential confounders. Our data show that serum DHEA-S levels are positively associated with serum AMH levels.


Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 759
Author(s):  
Byung Gon Kim ◽  
Seung Kil Lim ◽  
Sunga Kong

This study aims to assess the relationship between scapular upward rotation (SUR) across varying humeral-elevation angles (HEAs) and shoulder isokinetic strength and ratio in professional baseball pitchers. The subjects were professional baseball pitchers (n = 16) without a history of shoulder injury in the last six months. The subject’s SUR angles were measured with the humerus elevated at HEAs of 0° (at rest), 60°, 90°, and 120° to the scapular plane. Shoulder isokinetic strength was evaluated for shoulder internal rotation (IR) and external rotation (ER) strength (PT%BW and TW%BW), and the ER/IR strength ratios were determined at 60, 120 and 180°/s using an isokinetic dynamometer. The SUR angle at an HEA of 0° was positively correlated with IR strength at 120°/s (r = 0.535) and 180°/s (r = 0.522). The SUR angle at an HEA of 60° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.505) and 120°/s (r = −0.500). The SUR angle at an HEA of 90° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.574; r = −0.554) and 120°/s (r = −0.521; r = −0.589) as well as with ER strength at 180°/s (r = −0.591, r = −0.556). The SUR angle at an HEA of 120° was negatively correlated with ER strength at 60°/s (r = −0.558), 120°/s (r = −0.504; r = −0.524), and 180°/s (r = −0.543) and the ER/IR strength ratio at 60°/s (r = −0.517). In this study, we found that the ratio of isokinetic strength between ER and IR became closer to the normal range on increasing the SUR angle. In particular, an HEA of 90°, which resembles the pitching motion, showed a clear relationship between SUR, shoulder ER, and the ratio of ER/IR isokinetic strength in professional baseball pitchers.


Author(s):  
Oi-Ling Siu ◽  
Qianting Kong ◽  
Ting-Kin Ng

The COVID-19 pandemic has created more occupational stressors, particularly work–family interface issues. The purpose of this study was to investigate the moderating role of occupational stressors in the relationship between a personal resource (psychological capital) and family satisfaction. A cross-sectional study was carried out with a sample of 787 employees (367 males, 420 females) from the Greater Bay Area of China between October and November 2020. Participants completed an online survey which included the Chinese version of the Psychological Capital Questionnaire, measures of occupational stressors from the Work Stress Management DIY Kit and a measure of family satisfaction. Latent moderated structural equation modeling revealed that family satisfaction was positively associated with psychological capital and negatively associated with occupational stressors. Furthermore, occupational stressors weakened the positive association between psychological capital and family satisfaction. These findings provided empirical evidence for the work–home resources model and may suggest that it would be beneficial to boost psychological capital and reduce occupational stressors of employees.


2021 ◽  
Author(s):  
Pooja Sahni ◽  
Jyoti Kumar

History is replete with examples where humans have sought refuge in nature for psychological restoration. In this cross-sectional study we explore the relationship of nature experience and mindfulness. Nature experience is assessed through “nature in the neighbourhood”, “frequency of visit” to nature-rich spaces, as well as one's inherent connection with nature described as “nature relatedness”. The study sample consisted of 334 Indian adults. The findings from this study show that frequency of visit to nature-rich spaces has a significant positive association with mindfulness. The hierarchical regression analysis suggests an interaction effect of “nature relatedness” in the association of the presence of nature rich spaces in the neighbourhood, frequency of visit as well as mindfulness. Interestingly, when childhood experiences were explored they had a significant association with “nature relatedness” and mindfulness. The evidence from this research suggests that nature experience may find its application as one of the mindfulness techniques prescribed for self-management of mental health problems.


Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Mana Kogure ◽  
Tomohiro Nakamura ◽  
Naho Tsuchiya ◽  
Takumi Hirata ◽  
Akira Narita ◽  
...  

Introduction: Recently, the balance between sodium and potassium intake, i.e. sodium-to-potassium (Na/K) ratio, has received significant attention for prevention of hypertension. Previous studies reported the positive association between urinary Na/K (uNa/K) ratio and hypertension. However, even the same uNa/K ratio value, there might be high Na/ high K ratio or low Na/ low K ratio. Hypothesis: We assessed the hypothesis that blood pressure (BP) is higher in high Na/ high K group than that in low Na/ low K group even at the same uNa/K ratio in general population in cross-sectional study. Methods: The subjects were 20 to 74 years old who participated in The Tohoku Medical Megabank Project Community-based Cohort Study. Of these participants, we targeted 54,011 subjects (men: 20,505 women: 33,506 mean age: 59.9 years) who had information of BP, urinary Na and K. We estimated 24-h urinary excretion of Na and K using Tanaka formula. Urinary Na and K were each classified into quartiles (Na; Q1~Q4, K; Q1~Q4), and set all 16 groups of uNa/K ratio by combining Na and K respectively. To assess the relationship between casual uNa/K ratio and BP, we performed an analysis of covariance to calculate the adjusted mean systolic BP (SBP). We included covariate factors as age, sex, BMI and alcohol intake. We also assessed the relationship between uNa/K ratio and SBP using multiple regression analyses adjusted for covariate factors. We stratified the participants into two groups: ‘under treatment for hypertension’ (n=17,091) and ‘without treatment for hypertension (n=36,920)’. Results: The mean of uNa/K ratio for each group of Na (Q1)/K(Q1), Na (Q2)/K(Q2), Na (Q3)/K(Q3) and Na (Q4)/K(Q4) was all 4.0. As previous report showed, higher uNa/K ratio group showed higher SBP and lower uNa/K group showed lower BP. When we compared adjusted mean SBP of Na (Q1)/K(Q1) and Na (Q4)/K(Q4) the value were comparable, but the value were significantly higher in Na (Q4)/K(Q4) group (The adjusted mean SBP of Na (Q1)/K(Q1), Na (Q2)/K(Q2), Na (Q3)/K(Q3) and Na (Q4)/K(Q4) was 123.6, 124.9, 124.7 and 125.5 mmHg, respectively). The uNa/K was significantly positively associated with SBP independently of age, sex, BMI, and alcohol intake. The finding was unchanged the results in under treatment group. Conclusions: BP was significantly higher in high Na/ high K group than in low Na/ low K group even at the same uNa/K ratio. We suggested that not only increasing K intake but also reducing salt is important for preventing hypertension.


2018 ◽  
Vol 39 (8) ◽  
pp. 1024-1036 ◽  
Author(s):  
Jana Matošková ◽  
Lucie Macurová ◽  
Lucie Tomancová

Purpose The purpose of this paper is to examine whether and to what extent knowledge-oriented leadership (KOL) is associated with knowledge sharing (KS) in an organization as well as the dimensions of this leadership style. Design/methodology/approach Opinion-based questionnaires were applied in the study. A principal axis factor analysis was conducted to find the main factors in KOL (n=236). The relationship between KS and KOL was tested with Pearson’s correlation coefficient method. Findings The findings support the importance of high-quality leader–member exchange for KS because KOL had a strong significant positive association with the extent of KS in the organization (n=96, r=0.521). The principal axis factor suggested three factors, all of which were moderately significantly related to KS: the perceived support from the superior, enough time for KS and information flow from the superior. Research limitations/implications The research design in this study was cross-sectional. Thus, the interpretations of the cause–effect relationship among the variables could not be determined. Furthermore, the findings should be confirmed using a larger sample. Practical implications The study indicates that if innovativeness and the use of human capital are important for an organization’s competitive ability, it is vital to train managers to be able to apply KOL. Originality/value Few studies have addressed the relationship between leadership and KS. Hence, this study contributes to a better understanding of the relation between KS and KOL style. Additionally, KOL is probably a multidimensional construct, but little empirical work has been done to explore it.


2019 ◽  
Vol 47 (5) ◽  
pp. 1103-1110 ◽  
Author(s):  
Timothy B. Griffith ◽  
Christopher S. Ahmad ◽  
Prakash Gorroochurn ◽  
John D’Angelo ◽  
Michael G. Ciccotti ◽  
...  

Background: Professional baseball pitchers are at high risk for tears of the ulnar collateral ligament (UCL) of the elbow, often requiring surgical reconstruction. Despite acceptable published return-to-play outcomes, multiple techniques and graft types have been described. Purpose: This study compares UCL reconstruction (UCLR) outcomes based on tunnel configuration and graft type. Study Design: Cohort study; Level of evidence, 3. Methods: After approval from our institutional review board and Major League Baseball (MLB), 566 professional baseball pitchers who underwent UCLR between 2010 and 2014 were identified and included. The following patient characteristics were analyzed: age, pitching role (starter vs reliever), level of play (MLB vs Minor League Baseball [MiLB]), and throwing side dominance. Surgical factors analyzed included reconstruction technique, graft type, and concomitant procedures. Primary outcome measures consisted of the ability to return to play at any level (RTP), ability to return to the same level of play (RSL), time to return, subsequent elbow injuries, and need for subsequent or revision elbow surgery. The effects of patient and surgical factors on outcomes were analyzed using multivariate linear and logistic regression modeling. Results: The RTP rate was 79.9%, and the RSL rate was 71.2%. Grafts used to reconstruct the UCL included the palmaris longus autograft (n = 361, 63.7%), the gracilis autograft (n = 135, 23.8%), and other grafts (n = 70, 12.5%). Surgical techniques utilized were the docking technique (n = 171, 30.2%), the modified Jobe technique (n = 290, 51.2%), and other techniques (n = 105, 18.6%). There were no significant differences in the time to RTP or RSL based on reconstruction technique or graft type. RTP rates were similar for the docking versus modified Jobe technique (80.1% vs 82.4%, respectively; P = .537) and for the 2 primary graft types (83.1% for palmaris longus vs 80.7% for gracilis; P = .596). The rate of subsequent elbow surgery was 10.5% for the docking technique versus 14.8% for the modified Jobe technique ( P = .203), and the rate of revision UCLR was 2.9% versus 6.2% for the docking versus modified Jobe technique, respectively ( P = .128). Significant trends toward an increasing use of the palmaris longus autograft ( P = .023) and the docking technique ( P = .006) were observed. MLB pitchers were more likely than MiLB pitchers to RTP ( P < .001) and RSL ( P < .001), but they required a longer time to return (mean difference, 35 days; P = .039) and had a higher likelihood of subsequent elbow (odds ratio [OR], 3.58 [95% CI, 2.06-6.23]; P < .001) and forearm injuries (OR, 5.70 [95% CI, 1.99-16.30]; P = .004) but not subsequent elbow surgery. No specific variables correlated with the rates of subsequent elbow surgery or revision UCLR in the multivariate analysis. The use of concomitant ulnar nerve transposition did not affect outcomes. Conclusion: Surgical outcomes in professional baseball players are not significantly influenced by UCLR technique or graft type. There was a high rate (46.3%) of subsequent throwing elbow injuries. MLB pitchers were more likely to RTP and RSL, but they had a higher frequency of subsequent elbow and forearm injuries than MiLB pitchers. Both the docking technique and the palmaris longus autograft are increasing in popularity among surgeons treating professional baseball players.


2019 ◽  
Vol 2 (2) ◽  
pp. 100-109
Author(s):  
Dalal Usamah Alkazemi ◽  
Roberts Jackson

ObjectivesBreastfeeding (BF) has many benefits for both infants and mothers. However, despite evidence in support of BF, its prevalence has remained low in Kuwait. The purpose of this study was to (1) assess and describe BF attitudes and knowledge among women at a college campus; (2) evaluate BF exposures and sociodemographic factors associated with attitudes toward BF; (3) determine the association between BF knowledge and attitudes.Materials and methodsThis survey was a cross-sectional descriptive study conducted from February to April 2016. A convenience sample of 330 women (students, faculty and staff) from the College of Life Sciences (CLS) at Kuwait University participated in the survey.ResultsMost of the participants respected women who breast fed (81.8%). Some participants believed that BF a baby is painful (43.3%), makes the breasts sag (35.8%), and restricts the mothers’ freedom (51.5%). Additionally, 47.6% of the participants reported that they would feel embarrassed if they saw a woman BF her baby. Acceptability of BF in public was low and most participants preferred BF only around friends and family (52.4%). A statistically significant positive association was observed between BF knowledge and attitudes (R2=6.5%, p<0.001); however, the relationship was not independent and was also associated with nationality and having been breast fed as a baby (R2=10.3%, p=0.021).ConclusionBF knowledge is important to encourage positive BF attitudes, and both are enforced with family values and practice across generations.


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