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Brittany Dowling, Glenn S Fleisig
Determining and understanding baseball batting mechanics at various competition levels may help players and coaches identify key kinematics crucial to being a successful hitter. The purpose of this study was to compare batting kinematics across competition levels. Kinematic and temporal data were analysed for 170 male batters (youth n = 33; high school n = 69; college n = 22; professional n = 46) using 3D motion capture (480 Hz). The results showed differences in angular positions between competition levels during the five phases of the swing, with the greatest differences seen between the youth and professional batters...
September 2016: Sports Biomechanics
Jeffrey R Dugas, Benjamin B Bedford, John S Andrachuk, Anthony J Scillia, Kyle T Aune, E Lyle Cain, James R Andrews, Glenn S Fleisig
PURPOSE: To determine common mechanisms of anterior cruciate ligament (ACL) injury in baseball players and to quantify the rate of return to play after primary surgical reconstruction and review intermediate clinical outcomes. METHODS: Surgical injuries involving the ACL in youth, high school, collegiate, and professional baseball players were queried for an 11-year period (2001 to 2011). Over the study period, 42 baseball players were identified who had undergone arthroscopically assisted primary ACL reconstruction by 1 of 3 attending surgeons...
May 5, 2016: Arthroscopy: the Journal of Arthroscopic & related Surgery
Glenn S Fleisig, Walter A Laughlin, Kyle T Aune, E Lyle Cain, Jeffrey R Dugas, James R Andrews
Controversy continues whether curveballs are stressful for young baseball pitchers. Furthermore, it is unproven whether professional baseball pitchers have fewer kinematic differences between fastballs and off-speed pitches than lower level pitchers. Kinematic and kinetic data were measured for 111 healthy baseball pitchers (26 youth, 21 high school, 20 collegiate, 26 minor league, and 18 major league level) throwing fastballs, curveballs, and change-ups in an indoor biomechanics laboratory with a high-speed, automated digitising system...
June 2016: Sports Biomechanics
Walter A Laughlin, Glenn S Fleisig, Kyle T Aune, Alek Z Diffendaffer
Swing trajectory and ground reaction forces (GRF) of 30 collegiate baseball batters hitting a pitched ball were compared between a standard bat, a bat with extra weight about its barrel, and a bat with extra weight in its handle. It was hypothesised that when compared to a standard bat, only a handle-weighted bat would produce equivalent bat kinematics. It was also hypothesised that hitters would not produce equivalent GRFs for each weighted bat, but would maintain equivalent timing when compared to a standard bat...
2016: Sports Biomechanics
Jeffrey R Dugas, Brian L Walters, David P Beason, Glenn S Fleisig, Justin E Chronister
BACKGROUND: The number of throwing athletes with ulnar collateral ligament (UCL) injuries has increased recently, with a seemingly exponential increase of such injuries in adolescents. In cases of acute proximal or distal UCL insertion injuries or in partial-thickness injuries that do not respond to nonoperative management, UCL repair and augmentation rather than reconstruction may be a viable option. PURPOSE/HYPOTHESIS: The purpose of this study was to biomechanically compare a new technique of augmented UCL repair versus a typical modified Jobe UCL reconstruction technique...
March 2016: American Journal of Sports Medicine
Kevin E Wilk, Leonard C Macrina, Glenn S Fleisig, Kyle T Aune, Ron A Porterfield, Paul Harker, Timothy J Evans, James R Andrews
BACKGROUND: Shoulder injuries from repetitive baseball pitching continue to be a serious, common problem. PURPOSE: To determine whether passive range of motion of the glenohumeral joint was predictive of shoulder injury or shoulder surgery in professional baseball pitchers. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Passive range of motion of the glenohumeral joint was assessed with a bubble goniometer during spring training for all major and minor league pitchers of a single professional baseball organization over a period of 8 successive seasons (2005-2012)...
October 2015: American Journal of Sports Medicine
David P Beason, Jay P Shah, James W Duckett, Patrick W Jost, Glenn S Fleisig, E Lyle Cain
BACKGROUND: Humeral fracture following subpectoral biceps tenodesis has been previously reported; however, there are no published biomechanical studies reporting the resulting torsional strength of the humerus. Our purpose was to determine if there is an increased risk of humerus fracture after subpectoral biceps tenodesis with an interference screw and to determine if screw size is also a factor. We hypothesized that limbs receiving the procedure would have reduced failure torque and rotation under external rotation compared to untreated controls and that the larger screw size would result in inferior mechanical properties compared to the smaller...
November 2015: Clinical Biomechanics
Brent A Ponce, E Lyle Cain, Ryan Pflugner, Glenn S Fleisig, Bradley L Young, Hikel A Boohaker, Thomas A Swain, James R Andrews, Jeffrey R Dugas
Purpose The purpose of this study was to identify risk factors for revision surgery following primary anterior cruciate ligament (ACL) reconstruction. Methods A retrospective analysis of 2,965 patients who underwent a primary ACL reconstruction were separated into two groups: those who returned to our center for revision of their reconstruction (n = 67) and those who did not return to our center for revision of their reconstruction (n = 2,898). Patient characteristics assessed at the time of primary reconstruction include age, gender, graft type, graft source, meniscal and/or chondral injury, sport, side of effected extremity, level of competition, and surgeon...
May 2016: Journal of Knee Surgery
Stan A Conte, Glenn S Fleisig, Joshua S Dines, Kevin E Wilk, Kyle T Aune, Nancy Patterson-Flynn, Neal ElAttrache
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...
July 2015: American Journal of Sports Medicine
H B Fleisig, K R Hukezalie, C A H Thompson, T T T Au-Yeung, A T Ludlow, C R Zhao, J M Y Wong
Reactivation of telomerase reverse transcriptase (TERT) expression is found in more than 85% of human cancers. The remaining cancers rely on the alternative lengthening of telomeres (ALT), a recombination-based mechanism for telomere-length maintenance. Prevalence of TERT reactivation over the ALT mechanism was linked to secondary TERT function unrelated to telomere length maintenance. To characterize this non-canonical function, we created a panel of ALT cells with recombinant expression of TERT and TERT variants: TERT-positive ALT cells showed higher tolerance to genotoxic insults compared with their TERT-negative counterparts...
January 14, 2016: Oncogene
J R Dugas, A M Barrett, D P Beason, M F Plymale, G S Fleisig
Meniscocapsular separations are often seen in knees with other intra-articular pathology. The consequences of these tears with regard to knee contact mechanics are currently unknown, and the biomechanical advantages of repair have not been measured. We hypothesize that tears to the meniscocapsular junction will cause an increase in tibiofemoral contact pressure and a decrease in contact area, with a return to more normal conditions after repair. 10 fresh-frozen cadaver knees each underwent 10 cycles of axial compressive loading in full extension under three different testing conditions: intact, meniscocapsular separation, and repair...
June 2015: International Journal of Sports Medicine
Glenn S Fleisig, Charles E Leddon, Walter A Laughlin, Michael G Ciccotti, Bert R Mandelbaum, Kyle T Aune, Rafael F Escamilla, Toran D MacLeod, James R Andrews
BACKGROUND: A relatively high number of active professional baseball pitchers have a history of ulnar collateral ligament reconstruction (UCLr) on their throwing elbow. Controversy exists in the literature about whether professional baseball pitchers regain optimal performance after return from UCLr. It has been suggested that pitchers may have different biomechanics after UCLr, but this has not been previously tested. HYPOTHESIS: It was hypothesized that, compared with a control group without a history of UCLr, professional pitchers with a history of UCLr would have (1) significantly different throwing elbow and shoulder biomechanics; (2) a shortened stride, insufficient trunk forward tilt, and excessive shoulder horizontal adduction, characteristics associated with "holding back" or being tentative; (3) late shoulder rotation; and (4) improper shoulder abduction and trunk lateral tilt...
May 2015: American Journal of Sports Medicine
Anthony J Scillia, Kyle T Aune, John S Andrachuk, E Lyle Cain, Jeffrey R Dugas, Glenn S Fleisig, James R Andrews
BACKGROUND: Knee injuries, including articular cartilage damage, are common in football players and are potentially career threatening. The rate of return to play (RTP) as well as the factors affecting return after arthroscopic chondroplasty of the knee is performed in National Football League (NFL) athletes are not known. PURPOSE: To determine the rate of return to regular season NFL competition after arthroscopic knee surgery including chondroplasty of articular cartilage lesions...
March 2015: American Journal of Sports Medicine
Mickey Plymale, Glenn S Fleisig, Stephen M Kocaj, William P Cooney, Timothy J Evans, E Lyle Cain, Jeffrey R Dugas
Meniscal injuries commonly occur concomitantly with anterior cruciate ligament (ACL) injuries. Although many types of meniscal injuries have been described in the literature, there has not been much focus on meniscal capsular junction (MCJ) tears. This lack of attention is concerning given that, in a survey of 67 orthopedic surgeons, 88% indicated that MCJ tears could be a source of chronic pain. In addition, we reviewed 781 ACL reconstructions at our clinic and found a 12.3% incidence of MCJ tear with primary ACL injury and a 23...
November 2014: American Journal of Orthopedics
Walter A Laughlin, Glenn S Fleisig, Anthony J Scillia, Kyle T Aune, E Lyle Cain, Jeffrey R Dugas
BACKGROUND: Baseball pitchers who undergo superior labrum anterior-posterior (SLAP) repair often have trouble returning to their previous level of performance. While the reason is often assumed to be diminished shoulder range of motion or other mechanical changes, differences in pitching biomechanics between baseball pitchers with a history of SLAP repair and pitchers with no injury history have not been studied previously. HYPOTHESIS: The primary hypothesis was that compared with the control group, the SLAP group would exhibit compromised shoulder range of motion (external rotation and horizontal abduction) and internal rotation torque during pitching...
December 2014: American Journal of Sports Medicine
Kevin E Wilk, Leonard C Macrina, Glenn S Fleisig, Kyle T Aune, Ron A Porterfield, Paul Harker, Timothy J Evans, James R Andrews
BACKGROUND: Injuries to the elbow joint in baseball pitchers appear common. There appears to be a correlation between shoulder range of motion and elbow injuries. PURPOSE: To prospectively determine whether decreased ROM of the throwing shoulder is correlated with the onset of elbow injuries in professional baseball pitchers. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: For 8 consecutive years (2005-2012), passive range of motion of both the throwing and nonthrowing shoulders of all major and minor league pitchers within a single professional baseball organization were measured by using a bubble goniometer during spring training...
September 2014: American Journal of Sports Medicine
Stuart J Warden, Sara M Mantila Roosa, Mariana E Kersh, Andrea L Hurd, Glenn S Fleisig, Marcus G Pandy, Robyn K Fuchs
The skeleton shows greatest plasticity to physical activity-related mechanical loads during youth but is more at risk for failure during aging. Do the skeletal benefits of physical activity during youth persist with aging? To address this question, we used a uniquely controlled cross-sectional study design in which we compared the throwing-to-nonthrowing arm differences in humeral diaphysis bone properties in professional baseball players at different stages of their careers (n = 103) with dominant-to-nondominant arm differences in controls (n = 94)...
April 8, 2014: Proceedings of the National Academy of Sciences of the United States of America
Jingzhen Yang, Barton J Mann, Joseph H Guettler, Jeffrey R Dugas, James J Irrgang, Glenn S Fleisig, John P Albright
BACKGROUND: There are relatively few published epidemiological studies that have correlated pitching-related risk factors with increased pitching-related arm problems as well as injuries. HYPOTHESIS: High pitching volume and limited recovery will lead to arm fatigue, thus placing young pitchers at a greater risk for elbow and shoulder problems and, subsequently, an increased risk for arm injuries. STUDY DESIGN: Cross-sectional study; Level of evidence, 3...
June 2014: American Journal of Sports Medicine
Glenn S Fleisig, Wellington K Hsu, Dave Fortenbaugh, Andrew Cordover, Joel M Press
The purpose of this study was to quantify trunk axial rotation and angular acceleration in pitching and batting of elite baseball players. Healthy professional baseball pitchers (n = 40) and batters (n = 40) were studied. Reflective markers attached to each athlete were tracked at 240 Hz with an eight-camera automated digitizing system. Trunk axial rotation was computed as the angle between the pelvis and the upper trunk in the transverse plane. Trunk angular acceleration was the second derivative of axial rotation...
November 2013: Sports Biomechanics
R Meredith Elkins, Donna B Pincus, Jonathan S Comer
The Panic Disorder Severity Scale (PDSS; Shear et al., 1997) is a well-validated measure that assesses symptoms of panic disorder with or without agoraphobia (PDA) in adults. The Panic Disorder Severity Scale for Children (PDSS-C) is an adaptation of the PDSS for youth ages 11-17. The current study evaluated the psychometric properties of the PDSS-C. Participants included 60 adolescents from a randomized controlled trial investigating the efficacy of an intensive cognitive behavioral treatment (CBT) for adolescent PDA...
June 2014: Psychological Assessment
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