Background:
While the high rate of ulnar collateral ligament (UCL) injuries in professional baseball is widely discussed in the media and medical literature, the actual prevalence of UCL ...reconstruction has not been documented.
Hypothesis:
The prevalence of UCL reconstruction will be higher among pitchers than nonpitchers, and Major League Baseball (MLB) pitchers will have a higher prevalence than will minor league pitchers.
Study Design:
Descriptive epidemiology study.
Methods:
An online questionnaire was distributed to all 30 MLB organizations. Certified athletic trainers from each team administered the questionnaire to all players in the organization, including major league players and 6 levels of minor league players. Demographic data were compared between major and minor league players. Continuous variables (age, years of professional baseball, country of origin, etc) were compared with Student t tests (P < .05). Categorical variables (level, position, etc) were compared using chi-square analysis (P < .05).
Results:
A total of 5088 professional baseball players (722 major league and 4366 minor league) participated in the survey. Pitchers represented 53% of all players, and 497 players reported at least 1 UCL reconstruction, demonstrating a prevalence rate of 10% (497 of 5088). Pitchers reported a significantly higher prevalence of UCL reconstruction (16%; 437 of 2706) than nonpitchers (3%; 60 of 2382; P < .001). Among major league pitchers, 25% (96 of 382) had a history of UCL reconstruction, while minor league pitchers showed a 15% (341 of 2324) prevalence (P < .001). Major league pitchers were also significantly older (28.8 ± 3.9 years) than minor league pitchers (22.8 ± 3.0; P < .001). The majority of major leaguers (86%) had their UCL reconstruction as professional pitchers, whereas the majority of minor league pitchers (61%) underwent their UCL reconstruction during high school and college (P < .001). The rates of UCL revision, prior elbow surgery, prior shoulder surgery, and types of UCL graft were similar between the major league and minor league pitchers. No difference in prevalence was shown between pitchers born in the United States versus Latin American countries.
Conclusion:
Pitchers have a high prevalence of UCL reconstruction in professional baseball, with 25% of major league pitchers and 15% of minor league pitchers having a history of the surgery.
Genetic optimizations to achieve high-level production of three different proteins of medical importance for humans, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon alpha 2b ...(IFN-α2b), and single-chain antibody variable fragment (scFv-phOx), were investigated during high-cell-density cultivations of Escherichia coli. All three proteins were poorly expressed when put under control of the strong Pm/xylS promoter/regulator system, but high volumetric yields of GM-CSF and scFv-phOx (up to 1.7 and 2.3 g/liter, respectively) were achieved when the respective genes were fused to a translocation signal sequence. The choice of signal sequence, pelB, ompA, or synthetic signal sequence CSP, displayed a high and specific impact on the total expression levels for these two proteins. Data obtained by quantitative PCR confirmed relatively high in vivo transcript levels without using a fused signal sequence, suggesting that the signal sequences mainly stimulate translation. IFN-α2b expression remained poor even when fused to a signal sequence, and an alternative IFN-α2b coding sequence that was optimized for effective expression in Escherichia coli was therefore synthesized. The total expression level of this optimized gene remained low, while high-level production (0.6 g/liter) was achieved when the gene was fused to a signal sequence. Together, our results demonstrate a critical role of signal sequences for achieving industrial level expression of three human proteins in E. coli under the conditions tested, and this effect has to our knowledge not previously been systematically investigated.
Purpose: Bilateral force deficit occurs when the maximal generated force during simultaneous bilateral muscle contractions is lower than the sum of forces generated unilaterally. Neural inhibition is ...stated as the main source for bilateral force deficit. Based on differences in bilateral neural organization, there might be a pronounced neural inhibition for proximal compared to distal effectors. The aim of the present experiment was to evaluate potential differences in bilateral force deficit in proximal compared to distal effectors in lower extremities. Methods: Fifteen young adults performed single-joint maximal voluntary contractions in isometric dorsiflexion of ankle (distal) and knee (proximal) extension unilaterally and bilaterally. Results: Results showed a significant absolute bilateral force deficit for both proximal (123.46 ± 59.51 N) and distal effectors (33.00 ± 35.60 N). Interestingly, the relative bilateral force deficit for knee extension was significantly larger compared to dorsiflexion of ankle, 19.98 ± 10.04% and 10.27 ± 9.57%, respectively. Our results indicate a significantly higher bilateral force deficit for proximal effectors compared to distal effectors. Conclusion: Plausible explanations are related to neuroanatomical and neurophysiological differences between proximal effectors and distal effectors where proximal muscles have a higher potential for bilateral communication compared to distal muscles. In addition, higher forces produced with proximal effectors could cause a higher perceived exertion and cause a more pronounced bilateral force deficit to proximal effectors.
Abstract Genome-wide association studies have identified numerous genetic variants conferring autoimmune disease risk. Most of these genetic variants lie outside protein-coding genes hampering ...mechanistic explorations. Numerous mRNAs are also differentially expressed in autoimmune disease but their regulation is also unclear. The majority of the human genome is transcribed yet its biologic significance is incompletely understood. We performed whole genome RNA-sequencing RNA-seq to categorize expression of mRNAs, known and novel long non-coding RNAs lncRNAs in leukocytes from subjects with autoimmune disease and identified annotated and novel lncRNAs differentially expressed across multiple disorders. We found that loci transcribing novel lncRNAs were not randomly distributed across the genome but co-localized with leukocyte transcriptional enhancers, especially super-enhancers, and near genetic variants associated with autoimmune disease risk. We propose that alterations in enhancer function, including lncRNA expression, produced by genetics and environment, change cellular phenotypes contributing to disease risk and pathogenesis and represent attractive therapeutic targets.
High 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.
To examine the relationship between fastball velocity and elbow-varus torque in professional pitchers using between- and within-subjects statistical analyses.
Cross-sectional study.
Motion-analysis laboratory.
Using 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.
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.
The between-subjects analyses displayed a weak positive association between ball velocity and elbow-varus torque (
= 0.076,
= .03). The within-subjects analyses showed a considerably stronger positive association (
= 0.957,
< .001).
When 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.
Background:
Pitching biomechanics are associated with performance and risk of injury in baseball. Previous studies have identified biomechanical differences between youth and adult pitchers but have ...not investigated changes within individual young pitchers as they mature.
Hypothesis:
Pitching kinematics and kinetics will change significantly during a youth pitcher’s career.
Study Design:
Descriptive laboratory study.
Methods:
Pitching biomechanics were captured in an indoor laboratory with a 12-camera, 240-Hz motion analysis system for 51 youth pitchers who were in their first season of organized baseball with pitching. Each participant was retested annually for the next 6 years or until he was no longer pitching. Thirty kinematic and kinetic parameters were computed and averaged for 10 fastballs thrown by each player. Data were statistically analyzed for the 35 participants who were tested at least 3 times. Within-participant changes for each kinematic and kinetic parameter were tested by use of a mixed linear model with random effects (P < .05). Least squares means for sequential ages were compared via Tukey’s honestly significant difference test (P < .05).
Results:
Three kinematic parameters that occur at the instant of foot contact—stride length, lead foot placement to the closed side, and trunk separation—increased with age. With age, shoulder external rotation at foot contact decreased while maximum shoulder external rotation increased. Shoulder and elbow forces and torques increased significantly with age. Year-to-year changes were most significant between 9 and 13 years of age for kinematics and between 13 and 15 years for normalized kinetics (ie, scaled by bodyweight and height).
Conclusion:
During their first few years, youth pitchers improve their kinematics. Elbow and shoulder kinetics increase with time, particularly after age 13. Thus, prepubescent pitchers may work with their coaches to improve the motions and flexibility of the players’ bodies and the paths of their arms. Once proper mechanics are developed, adolescent pitchers can focus more on improving strength and power.
Background: In previous studies the presence of a distinct gene expression pattern has been shown in peripheral blood cells from patients with autoimmune disease. Objective: To determine whether ...other specific signatures might be used to identify subsets of these autoimmune diseases and whether gene expression patterns in early disease might identify pathogenetic factors. Methods: Peripheral blood mononuclear cells were acquired from patients with rheumatoid arthritis (RA) and analysed by microarrays containing over 4300 named human genes. Patients with RA for <2 years were compared with subjects with longstanding RA (average duration 10 years) and with patients with other immune or autoimmune diagnoses. Results: Cluster analyses permitted separation of the patients with early RA (ERA) from those with longstanding disease. Comparison with other patient groups suggested that the ERA signature showed some overlap with that seen in the normal immune response to viral antigen as well as with a subset of patients with systemic lupus erythematosus. Conclusions: The ERA signature may reflect, in part, a response to an unknown infectious agent. Furthermore, shared features with some lupus patients suggest that common aetiological factors and pathogenetic pathways may be involved in these two autoimmune disorders.
Background:
Lateral meniscal injury is a common and possibly career-threatening injury among players in the National Football League (NFL). The rate of return to play (RTP) and factors that affect ...RTP after lateral meniscal injury in NFL players are currently not defined.
Purpose:
The aims of this study were to determine the rate of RTP to regular-season NFL game play of NFL players after arthroscopic partial lateral meniscectomy and to identify factors that can predict the ability to return to play.
Study Design:
Case series; Level of evidence, 4.
Methods:
Seventy-two patients undergoing 77 arthroscopic lateral partial meniscectomies were followed to determine the rate of RTP (defined as successful RTP in at least 1 regular-season NFL game after meniscectomy) and factors predicting players’ ability to return to play. Perioperative variables were recorded using retrospective chart review. Players’ heights and weights, dates of return, draft rounds, and counts of games, starts, and seasons both before and after meniscectomy were all collected from statistical databases maintained by the NFL. Chi-square and Student t tests were performed to assess differences among covariates with respect to an athlete’s ability to return to play, and odds ratios were calculated as appropriate. All percentages were calculated as percent of total procedures performed (n = 77).
Results:
Of the 77 partial lateral meniscectomies performed, 61% (n = 47) resulted in the athlete returning to play at his previous level of competition with an average length of time to RTP of 8.5 months; 19 (40%) of those who returned were still active in the NFL at the time of follow-up. Age at time of surgery, games and seasons played before surgery, and individual position were not significantly different between those who did and did not return to play. Undergoing a concomitant procedure did not affect an athlete’s ability to return to play, nor did concurrent arthroscopic anterior cruciate ligament reconstruction affect a player’s likelihood to return to play. Players drafted in the first 4 rounds of the NFL draft were 3.7 times more likely to return to play than players drafted after the fourth round, and players who started more than 46.2% of their games played (the mean value for this population) were 2.8 times more likely to return to play. Speed-position players (running backs, receivers, linebackers, and defensive backs) were 4.0 times less likely to return to play than non–speed position players (linemen and tight ends).
Conclusion:
The majority of NFL players undergoing arthroscopic lateral meniscectomy are able to return to play. Players selected earlier in the NFL draft and who are listed as starters in more of their games are more likely to return to play, as are linemen and tight ends. It is significantly more difficult for running backs, receivers, linebackers, and defensive backs to return to play.
To determine if individuals with metabolic disorders possess unique gene expression profiles, we compared transcript levels in peripheral blood from patients with coronary artery disease (CAD), type ...2 diabetes (T2D) and their precursor state, metabolic syndrome to those of control (CTRL) subjects and subjects with rheumatoid arthritis (RA). The gene expression profile of each metabolic state was distinguishable from CTRLs and correlated with other metabolic states more than with RA. Of note, subjects in the metabolic cohorts overexpressed gene sets that participate in the innate immune response. Genes involved in activation of the pro-inflammatory transcription factor, NF-κB, were overexpressed in CAD whereas genes differentially expressed in T2D have key roles in T-cell activation and signaling. Reverse transcriptase PCR validation confirmed microarray results. Furthermore, several genes differentially expressed in human metabolic disorders have been previously shown to participate in inflammatory responses in murine models of obesity and T2D. Taken together, these data demonstrate that peripheral blood from individuals with metabolic disorders display overlapping and non-overlapping patterns of gene expression indicative of unique, underlying immune processes.
The purpose of this study was to determine how often flaws in pitching mechanics identified from biomechanical analysis are corrected. The biomechanics of 46 baseball pitchers were evaluated twice, ...with an average of 12 months (range 2-48 months) between evaluations. Pitchers were healthy at the time of both evaluations, competing at the high school, college, minor league or Major League level. After warming up, each participant pitched 10 full-effort fastballs. Automated three-dimensional motion analysis was used to compute eight kinematic parameters which were compared with a database of elite professional pitchers. Flaws-defined as deviations from the elite range-were explained to each participant or coach after his initial evaluation. Data from the second evaluation revealed that 44% of all flaws had been corrected. Flaws at the instant of foot contact (stride length, front foot position, shoulder external rotation, shoulder abduction, elbow flexion) or slightly after foot contact (time between pelvis rotation and upper trunk rotation) seemed to be corrected more often than flaws near the time of ball release (knee extension and shoulder abduction). Future research may determine which level athletes or which training methods are most effective for correcting flaws.
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