Glenn S Fleisig

Glenn S Fleisig
American Sports Medicine Institute

PhD

About

239
Publications
220,263
Reads
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Introduction
Thank you to those interested our research studies. For copies of specific papers, please find them at www.pubmed.gov, a library, or an online reference resource. - Glenn S. Fleisig, Ph.D. Research Director American Sports Medicine Institute Birmingham, Alabama www.asmi.org glennf@asmi.org 205-918-2139
Additional affiliations
July 1987 - present
American Sports Medicine Institute
American Sports Medicine Institute
Position
  • Research Director

Publications

Publications (239)
Article
Full-text available
Background Biomechanical efficiency, defined as fastball velocity per unit of normalized elbow varus torque, is a relatively new metric applied to improving the performance and health of baseball pitching. Purpose/Hypothesis The purpose of this work was to evaluate kinematic parameters influencing biomechanical efficiency among professional and co...
Article
Background Ulnar collateral ligament (UCL) surgery continues to demonstrate excellent clinical outcomes and a high return-to-play (RTP) rate with a low complication rate. Recent studies have demonstrated similar clinical outcomes for baseball players who have undergone either UCL reconstruction or UCL repair. In comparison, few studies have assesse...
Article
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Endoscopic gluteus medius repair is indicated after failed conservative management for debilitating peritrochanteric hip pain. In our experience, most of these surgeries are performed on women, 45 to 75 years old. Often for undersurface high-grade partial-thickness tears and some small full-thickness tears, a single-row repair technique is performe...
Article
Objective: To evaluate the outcomes of patients treated with a novel minimally-invasive complete release of the first dorsal compartment percutaneously under ultrasound guidance using an 18-gauge needle with an 18 blade at the tip. Design: Retrospective case series. Nine adults (ten wrists) were included in the study of this technique. All patie...
Article
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Background: Lateral epicondylitis is one of the most common causes of elbow pain. Most patients recover with conservative treatments; however, some patients require surgical intervention. There are 3 common procedures offered: open tenotomy, arthroscopic tenotomy, and percutaneous microtenotomy. In comparison, percutaneous microtenotomy has been p...
Article
Objectives In the medical literature regarding injuries of the ulnar collateral ligament (UCL), baseball players comprise a majority of the athletes studied. Baseball players endure repetitive valgus forces in the elbow that can cause damage to the UCL with the overhead throwing motion. However, there are limited studies in the literature regarding...
Article
The objective was to assess how patellofemoral loads (joint force and stress) change while lunging with step length and step height variations. Sixteen participants performed a forward lunge using short and long steps at ground level and up to a 10-cm platform. Electromyography, ground reaction force, and 3D motion were captured, and patellofemoral...
Article
Background: A plantar fasciotomy using a microdebrider coblation wand may be an effective treatment for treating chronic plantar fasciitis. The objective of this prospective study was to determine the success rate of performing a plantar fasciotomy using a microdebrider coblation wand to treat plantar fasciitis and determine utility of ultrasonogr...
Article
BACKGROUND Previous studies have reported return to play (RTP) rates for athletes after lumbar discectomy, but not specifically younger athletes. The purpose of this study was to evaluate RTP rate of young athletes after lumbar microdiscectomy. METHODS Medical records for a single spine surgeon were reviewed to identify lumbar microdiscectomy pati...
Article
The purpose of this study was to investigate potential differences in lead knee extension velocity, elbow varus torque and lead knee extension (the change in lead knee flexion from foot contact to ball release) in high and low velocity professional pitchers. Three-dimensional motion capture (480 Hz) was used to assess 322 professional pitchers. T-t...
Article
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Background: Forward and side lunge exercises strengthen hip and thigh musculature, enhance patellofemoral joint stability, and are commonly used during patellofemoral rehabilitation and training for sport. Hypothesis/purpose: The purpose was to quantify, via calculated estimates, patellofemoral force and stress between two lunge type variations...
Article
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Background Recent innovative techniques have led to renewed interest in ulnar collateral ligament (UCL) repair. Although early outcome data regarding the clinical outcome of overhead athletes undergoing UCL repair with augmentation have been encouraging, long-term data are still needed to evaluate both the appropriate indications and success rate f...
Article
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Objectives All-suture anchor use for rotator cuff repair is increasing. Potential benefits of these anchors include less bone loss from anchor hole drilling and decreased injury to the chondral surface with anchor pullout. Minimal evidence exists comparing clinical outcomes of all suture to solid medial row anchor fixation in double row suture brid...
Article
Background: Trends over time in the incidence of ulnar collateral ligament (UCL) surgeries in National Collegiate Athletic Association Division I baseball players are currently unknown. Purpose/hypothesis: The purpose of this study was to evaluate the trends in UCL surgeries over 3 years in Division I baseball programs. We hypothesized that surg...
Article
Introduction: Open surgical trigger finger release has limited success with complications; however, percutaneous techniques have a successful alternative. There is limited understanding of the success of percutaneous trigger finger release. Objective: To prospectively evaluate the functional outcomes of patients with Green classification Grade 2...
Article
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Baseball coaches often focus on the landing position of a pitcher’s front foot as a key aspect of mechanics. Furthermore, controversy persists regarding positioning the rear foot on the first base or third base end of the rubber. The purpose of this study was to determine the effect of rear and front foot placement on pitching biomechanics. Our hyp...
Article
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Background There is limited literature regarding outcomes after operative treatment of displaced medial epicondyle avulsion fractures in adolescent athletes. Most studies have had a relatively small sample size and have not assessed return to play of the overhead athlete. Purpose To examine return to play and outcomes of youth overhead athletes wh...
Article
Background: There is a lack of evidence regarding the success of ulnar collateral ligament (UCL) revision reconstruction. Understanding outcomes after UCL revision reconstruction is important in clinical decision making for overhead athletes. Purpose: To evaluate return to play and patient-reported outcomes after UCL revision reconstruction. Stud...
Article
Background: Bone marrow aspiration (BMA) is among a group of autologous cell-based therapies currently being explored to treat osteoarthritis (OA). Materials & methods: This retrospective case study observed ten patients (13 knees) with severe knee OA who failed extensive conservative treatment and were treated with BMA injection using a novel, pur...
Article
Background: Baseball pitching injuries are increasing at an alarming rate. While weighted ball throwing programs may be effective at increasing pitching velocity, previous research has identified a 24% injury rate and a 3.3° increase in shoulder external rotation (ER) range of motion (ROM) after performing a 6-week program. However, previous resea...
Article
Objective: Trigger finger at the A1 pulley is a common cause of hand pain leading to functional limitations. This study evaluated the outcomes of patients treated with a micro-invasive ultrasound-guided trigger finger release technique using an 18 blade and described three tests that confirm a complete release. Design: A retrospective chart revi...
Article
Objectives Understanding the differences in baseball pitching biomechanics between American and Japanese pitchers may help with training and developing these athletes. The purpose of this study was to investigate the kinematic and kinetic differences in collegiate baseball pitchers from United States of American and Japan. Design Controlled labora...
Article
Full-text available
Objective To compare screw fixation strength for subtalar arthrodesis. Methods Eight matched pairs of cadaver feet underwent subtalar joint arthrodesis with two 7.3mm cannulated screws. Randomization was used to assign screw orientation, such that one foot in each pair was assigned dorsal to plantar screw orientation (DP Group), and the other foot...
Article
Objectives: To determine whether increasing pitching distance for adult baseball pitchers would affect their upper extremity kinetics, full-body kinematics, and pitched ball kinematics (ball velocity, duration of ball flight, vertical and horizontal break, strike percentage). Design: Controlled laboratory study. Methods: Twenty-six collegiate...
Article
Background Plantar fasciitis is the most common cause of heel pain in adults. Multiple conservative treatment plans exist; however, some cases do not obtain significant clinical improvement with conservative treatment and require further intervention. This retrospective case study evaluated the success rate of percutaneous plantar fasciotomy and co...
Chapter
Participation in sports has been an important part of culture and childhood development. Injuries to the lumbar spine can preclude participation with devastating social, psychological, and physical consequences. The clinical presentation of adolescent lumbar disc herniations often differs from adult patients (less neurologic symptoms), frequently d...
Article
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Category Basic Sciences/Biologics, Hindfoot Introduction/Purpose Arthrodesis of the subtalar joint is performed for various arthritic and instability problems to correct alignment and relieve pain. For talocalcaneal pathologies, isolated subtalar arthrodesis has been advocated with the advantages of lower risk of adjacent joint arthritis and nonun...
Article
Background The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is unknown. Hypothesis (1) Elbow torque and ball velocity would increase as throwers progressed through a structured long-toss program. (2) Intrathrower reliability would be high while interthrower reliability would be...
Article
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Background Injury prevalence has been well described among baseball athletes; similarly, a better understanding of injuries in softball athletes is needed. Purpose To examine shoulder and elbow injury epidemiology among high school softball athletes in the United States. Study Design Descriptive epidemiological study. Methods Injury data were ob...
Article
The purpose of this study was to explore the relationship between variability in pitching kinematics and consistency in pitch location. Data were collected for 47 healthy baseball pitchers throwing ten full-effort fastballs to the centre of the strike zone. For each pitch, 20 kinematic parameters were calculated with an automated motion capture sys...
Article
Background Proximal hamstring tendon avulsions are debilitating and commonly cause pain, weakness, and functional limitations. Open surgical repair has been the standard, but improved endoscopic techniques have enabled proximal hamstring fixation with decreased risk of infection and numbness, without the morbidity of a large incision. Purpose/Hypo...
Article
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Background The probability of returning to competition for injured baseball pitchers is similar after ulnar collateral ligament (UCL) repair as after UCL reconstruction, but the time to return is significantly quicker after UCL repair. Previous research has found no differences in pitching biomechanics between pitchers with and without a history of...
Article
Major League Baseball (MLB) players represent a unique population of individuals in the United States: a select group of men who possess the athleticism, strength, and acumen to navigate into organized professional baseball at the highest level and who are compensated quite well. What do we know about their health and mortality risks? In this issue...
Article
Objectives: To determine whether mound height is associated with baseball movement (velocity, spin and break) and baseball pitching biomechanics (kinematics and kinetics). Design: Controlled laboratory study. Methods: Twenty collegiate baseball pitchers threw five fastballs and five curveballs from four different mound heights (15cm, 20cm, 25c...
Article
The anterior bundle of the ulnar collateral ligament (UCL) is the primary restraint to valgus force at the elbow, especially during the arm-cocking and arm-acceleration phases of the overheard throwing cycle. Injuries of the UCL can range from partial thickness tears, end avulsions, to chronic attritional ruptures with poor tissue quality. The inci...
Article
Full-text available
Objectives Recent studies in the literature have highlighted the progressive increase in the incidence of ulnar collateral ligament (UCL) injuries to the elbow in baseball players of all levels. However, knowledge of the incidence and other epidemiological factors regarding UCL injuries, specifically in college baseball players, is currently lackin...
Article
Full-text available
Objectives Return to play (RTP) are high following lower extremity injuries; however, objective sport specific clearance criteria are lacking. In ACL rehabilitation for example, current tests that are used such as single leg hop, isokinetic testing, and quad strength are not sport specific and do not take fatigue into account. With the development...
Article
Full-text available
Objectives The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is yet to be fully elucidated. The primary aims of this study were to assess various throwing metrics through a structured long-toss program using wearable technology and to quantify the intra and inter thrower variabili...
Article
Full-text available
Objectives Progressive throwing programs are a mainstay of rehabilitating the throwing athlete after injury or surgery. Athletes are commonly asked to throw at reduced levels of effort (i.e. “50% effort”, ”75%,” etc) to minimize stress to healing tissues. However, it is unknown whether players’ perceived exertion matches actual exertion. The purpos...
Article
Background: During rehabilitation throwing programs, baseball players are commonly asked to throw at reduced levels of effort (ie, 50% effort, 75% effort, etc) to moderate stress to healing tissues. It is currently unknown how changes in players' perceived exertion compares with changes in actual exertion during structured long-toss programs. Pur...
Article
Background:: There has been a renewed interest in ulnar collateral ligament (UCL) repair in overhead athletes because of a greater understanding of UCL injuries, an improvement in fixation technology, and the extensive rehabilitation time to return to play. Purpose/hypothesis:: To evaluate the clinical outcomes of a novel technique of UCL repair...
Article
Context: 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,...
Article
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Background: Although baseball injuries are common in both Japan and the United States, the majority of pitching injuries in Japanese players occur at the shoulder, whereas most pitching injuries in American players occur at the elbow. A biomechanical comparison between Japanese and American pitchers may help to identify the different injury mechan...
Article
Background: Pitching injuries continue to be a serious problem, with adolescents now representing the group with the most injuries. Some have proposed that lowering or eliminating the pitching mound in youth baseball may reduce joint stress and subsequent injuries. Another potential risk factor is advancing from youth to adult pitching distance wi...
Article
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Objectives There has been a renewed interest in UCL repair in overhead athletes. This is largely due to greater understanding of UCL pathology, improvement in fixation technology and the extensive rehab required to return from UCL reconstruction. Initial data regarding UCL repair in overhead athletes was poor and therefore UCL repair was largely ab...
Article
Full-text available
Background: Emphasis on enhancing baseball pitch velocity has become popular, especially through weighted-ball throwing. However, little is known about the physical effects or safety of these programs. The purpose of this study was to examine the effects of training with weighted baseballs on pitch velocity, passive range of motion (PROM), muscle...
Article
The purpose of this study was to assess biomechanical differences among overhand, three-quarter, and sidearm arm-slot professional baseball pitchers. It was hypothesized that kinematic-and-kinetic differences would be found among the three groups, with sidearm pitchers demonstrating greater movement along the transverse plane, and overhead pitchers...
Article
Full-text available
Background Recent reports have highlighted the progressive increase in the incidence of ulnar collateral ligament (UCL) injuries to the elbow in baseball players of all levels. However, knowledge of the incidence and other epidemiological factors regarding UCL injuries, specifically in college baseball players, is currently lacking. Purpose To eva...
Article
While 10% of the general population is left-handed, 27% of professional baseball pitchers are left-handed. Biomechanical differences between left- and right-handed college pitchers have been previously reported, but these differences have yet to be examined at the professional level. Therefore, the purpose of this study was to compare pitching biom...
Article
Research has shown relations between amount of baseball pitching and overuse injuries, as well as between poor mechanics and high loads on the elbow and shoulder. However, overuse injuries continue to be a problem from youth to professional sports. Emerging wearable technology may enable players, parents, coaches, leagues, and clinicians to monitor...
Article
Background: Few studies have documented the outcomes of superior labral anterior-posterior (SLAP) repairs in baseball players. Furthermore, the results of these previous studies varied widely and were based on small numbers of patients. Hypothesis/Purpose: The purpose was to report return-to-play (RTP) rates and validated subjective outcome scores...
Article
Background: In professional baseball pitchers, pitching biomechanics have not been examined for the slider, and the only known study for the curveball and changeup examined limited kinetics. Moreover, no known studies have investigated pitching biomechanics between strikes and balls. Purpose/Hypothesis: The purpose was to compare pitching biomecha...
Article
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 dur...
Article
Background: Likely due to the high level of strain exerted across the elbow during the throwing motion, elbow injuries are on the rise in baseball. To identify at-risk athletes and guide postinjury return-to-throw programs, a better understanding of the variables that influence elbow varus torque is desired. Purpose: To describe the within-subje...
Article
Full-text available
Forces imparted by the fingers onto a baseball are the final, critical aspects for pitching, however these forces have not been quantified previously as no biomechanical technology was available. In this study, an instrumented baseball was developed for direct measurement of ball reaction force by individual fingers and used to provide fundamental...
Article
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 schoo...
Article
Full-text available
Objectives Likely due to the high level of strain exerted across the elbow during the throwing motion, elbow injuries are on the rise in baseball. In order to identify at risk athletes and guide post-injury return to throw programs, a better understanding of the variables that influence elbow varus torque is desired. The purpose of this work was to...
Conference Paper
Full-text available
The purpose of this study was to investigate the kinematic and kinetic differences between American and Japanese baseball pitchers. Kinematic and kinetic data were analyzed for 11 American pitchers (21±2 y, 190±6 cm, 93±9 kg) and 11 Japanese pitchers (21±1 y, 180±6 cm, 81±7 kg) using 3D motion capture (480 Hz). The American pitchers generated faste...
Article
Background: Anterior cruciate ligament (ACL) injuries occur commonly in football. Recent work has reported ACL reconstruction (ACLR) as one of several orthopaedic procedures with unfavorable outcomes for professional athletes. The performance impact to defensive players after surgery has not been quantified. Purpose: To quantify the effect of AC...
Article
This article aims to evaluate factors associated with chondral and meniscal lesions in primary and revision anterior cruciate ligament (ACL) reconstructions. ACL reconstructions from 2001 to 2008 at a single institution were retrospectively analyzed. Logistic regression was used to estimate the association between chondral and meniscal injuries and...
Article
Full-text available
Background: Weighted-ball throwing programs are commonly used in training baseball pitchers to increase ball velocity. The purpose of this study was to compare kinematics and kinetics among weighted-ball exercises with values from standard pitching (ie, pitching standard 5-oz baseballs from a mound). Hypothesis: Ball and arm velocities would be...