Hillary Plummer

U.S. Army Aeromedical Research Laboratory

The purpose of the current study was to quantitatively examine the muscle activations of 3 common isometric core exercises (abdominal bridge, single-leg abdominal bridge, and superman) along with a newly introduced isometric exercise (flying squirrel) and determine if muscle activations differed among the exercises. The design was a comparison stud...

The baseball pitching motion is a total kinetic chain activity that must efficiently utilize both the upper and lower extremity. Of particular importance is the scapular motion, which is critical for humeral positioning as well as proper alignment of shoulder musculature. It was hypothesized that scapular stability is enhanced by pelvic girdle stab...

Abstract The catcher has the most demanding position in the games of baseball and softball with no regulations on how many throws they make during game. It was the purpose of this study to describe the kinematics and kinetics of the throwing motion in catchers when throwing down to second base. It was hypothesised that younger and older catchers wo...

Lacrosse is one of the oldest team sports in the United States and it has become the fastest growing sport in the country. The purpose of this study was to describe the kinematics of the overhead shot in youth male lacrosse players in attempt to gain an understanding of the movement patterns of the upper extremity. It was hypothesized that the kine...

Background Ulnar collateral ligament (UCL) tears in the throwing elbow are classified according to grade and location using magnetic resonance arthrography (MRA). However, the frequency of each tear type and the association to age, competition level, and radiographic findings in adolescent baseball pitchers are unknown. Purposes The primary purpos...

Background: Hip strength is an important factor for control of the lumbo-pelvic-hip complex. Deficits in hip strength may affect throwing performance and contribute to upper extremity injuries. Hypothesis: Deficits in hip abduction isometric strength would be greater in those who sustained an upper extremity injury and hip strength would predict i...

Background Inconsistent findings exist between drive-leg ground-reaction forces (GRFs) and pitching mechanics. Previous literature has largely reported drive-leg mechanics and GRFs at the start of the pushoff phase for their role in initiating force development. Little research has assessed drive-leg kinematics that includes a pitcher’s windup moti...

Background Autologous platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMC) are being used clinically as therapeutic agents for the treatment of knee osteoarthritis. Purpose/Hypothesis The purpose of this study was to compare the efficacy of BMC and PRP on pain and function in patients with knee osteoarthritis up to 24 months after...

Purpose The purpose of this study was to determine the effects of blood flow restriction (BFR) using a pneumatic tourniquet on CD34⁺ cells, platelets, white blood cells, neutrophils, lymphocytes, lactate, and glucose compared with standard exercise. Methods Fifteen healthy volunteers (8 males and 7 females, 28.6 ± 3.6 years old) who were able to p...

# Background Deficits in shoulder range of motion (ROM) and strength are associated with risk of arm injury in baseball players. # Purpose The purpose of this study was to assess the effectiveness of a standardized exercise program, during the fall season, on shoulder ROM and rotational strength in collegiate baseball players. # Study Design P...

Background High shoulder distraction force has been observed in softball pitchers during the acceleration phase (top of the pitch to ball release) of a pitch. Increasing elbow flexion may reduce shoulder forces and the susceptibility to pain by shortening the lever arm of the throwing arm. Purpose To determine the association of peak elbow flexion...

Background: Examining range of motion deficits across levels of baseball competition can result in a better understanding of the extent of altered range of motion patterns and identify competition levels that may require preventative interventions that target the deficits. Purpose: The purpose of this study was to compare shoulder range of motio...

Purpose The objective of this study was to perform a systematic review of clinical outcome studies exploring cellular augmentation of ACL surgery, including stem cell techniques. Methods A systematic search was performed according to the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) guidelines utilizing the Cochrane, P...

Background: Limitations in passive hip range of motion (PROM) may negatively affect pitching mechanics in baseball pitchers. Understanding the relationships between PROM and mechanics can assist in the development of injury prevention protocols. Purpose: The purpose of this study was to examine the association of hip rotational PROM with pelvis...

Background The paucity of longitudinal clinical studies limits our understanding of the development of shoulder pain with repetitive shoulder tasks, and its association with underlying mind and body mechanisms. Tendon thickening characterizes painful shoulder supraspinatus tendinopathy, and the perception of pain can be affected by the presence of...

Background Glenohumeral internal rotation deficit (GIRD) and total arc of motion difference (TAMD) have been associated with elbow injuries in throwing athletes. Hypothesis Youth pitchers with elbow pain will have greater GIRD and TAMD compared with youth pitchers without elbow pain. Study Design Cross-sectional study. Level of Evidence Level 3....

# Background Shoulder strength deficits are implicated in arm injuries and performance deficits in baseball players. # Purpose To characterize shoulder external (ER) and internal (IR) rotation strength in professional baseball players, and compare strength across player type (pitchers, position players) and geographic origin (North America, Lat...

Objective: To characterize recurrent instability, return to sport (RTS), and patient-reported outcomes (PROs) after arthroscopic Bankart repair for acute traumatic anterior shoulder instability in National Collegiate Athletic Association (NCAA) and National Football League (NFL) football players. Design: Case series. Setting: Orthopaedic and s...

Purpose: The primary objective of this study was to reproduce and validate the harvest, processing and storage of peripheral blood stem cells for a subsequent cartilage repair trial, evaluating safety, reliability, and potential to produce viable, sterile stem cells. Methods: Ten healthy subjects (aged 19-44 years) received three consecutive dai...

Background: The single-leg step down task (SLSD) is a clinical tool to assess movement and control of the lower extremity and trunk. Hip abduction weakness may impact movement quality during the SLSD, however the relationships between movement and strength are unclear. Purpose: To determine the relationship between hip abduction isometric streng...

Purpose To analyze the cellular response and chemokine profiles following exercise using cooling and blood flow restriction on the Vasper system. Methods Healthy male patients between the ages of 20 and 39 years were recruited. Testing was performed on the Vasper system, a NuStep cross-trainer with concomitant 4-limb venous compression with proxim...

Purpose To determine the effects of blood flow restriction (BFR) exercise on CD34⁺ cells, platelets, white blood cells, neutrophils, lymphocytes, lactate, and glucose. Methods Healthy participants aged 20 to 39 years who were able to perform the exercise sessions were recruited. Participants underwent an experimental (EXP) occluded testing session...

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...

Purpose: The purpose of this study was to assess if point of care devices designed for collecting cellular components from blood or bone marrow could be used to isolate viable stem cells from synovial fluid. Methods: Male and female patients greater than 18 years old with either an acute, anterior cruciate ligament (ACL) injury or knee osteoarth...

Purpose The primary purpose of this study was to determine the cellular composition of a product created with peripheral blood harvested after systemic mobilization with filgrastim and processed with one point-of-care blood concentrating system, i.e. platelet rich plasma (PRP) system. The second purpose was to compare M-PRP to a concentrated bone m...

Objective To characterise whether preseason screening of shoulder range of motion (ROM) is associated with the risk of shoulder and elbow injuries in overhead athletes. Design Systematic review and meta-analysis. Data sources Six electronic databases up to 22 September 2018. Eligibility criteria Inclusion criteria were (1) overhead athletes from...

Objectives: Though pitchers often throw during multiple games in a day, there are currently no pitch count restrictions in softball. The accumulation of high pitch counts over time may contribute to the development of upper extremity pain. The purpose of our study was to examine functional characteristics of shoulder and hip range of motion (ROM),...

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...

The purpose of this study was to assess the effects of a standardized exercise program on shoulder ROM, shoulder and hip strength and lumbopelvic stability over the course of a playing season in collegiate baseball players.

Background: To compare the activation of shoulder and trunk muscles between six pairs of closed (CC) and open chain (OC) exercises for the upper extremity, matched for performance characteristics. The secondary aims were to compare shoulder and trunk muscle activation and shoulder activation ratios during each pair of CC and OC exercise. Methods:...

The number of ulnar collateral ligament (UCL) injuries in adolescent baseball pitchers has risen over the past 2 decades with the incidence of UCL reconstructions also increasing dramatically over that time period. The Joyner-Andrews magnetic resonance imaging (MRI) classification of UCL tears has previously been described to describe the grade and...

Context: Rowers are at risk for overuse injuries, including low back pain (LBP). Defining the utility of screening tests for identifying those at risk for LBP can aid in the development of guidelines for injury prevention. Objective: To determine if the Functional Movement Screen (FMS) and impairments can identify rowers at risk for developing L...

Background: Fastpitch softball is a popular sport for young females. However, data are limited describing youth pitching mechanics. Normative data describing pitching mechanics in the two youngest player pitch leagues are critical to gaining an improved understanding of proper mechanics in an attempt to establish injury prevention programs. Purpo...

Background: Impaired trunk motion during pitching may be a risk factor for upper extremity injuries. Specifically, increased forces about the shoulder and elbow have been observed in pitchers with excessive contralateral trunk lean during pitching. Because of the difficulty in identifying abnormal trunk motions during a high-speed task such as pitc...

Hematopoetic stem cells (HSC) have recently been studied to improve healing and rehabilitation from musculoskeletal injury. HSC are currently collected using invasive bone marrow aspiration and peripheral harvest after pharmaceutical mobilization. Animal studies show environmental stresses including heat, hypoxia, and cold mobilize HSC. HSC have al...

Context: Hip abductor musculature contributes to the stability of the pelvis, which is needed for efficient energy transfer from the lower extremity to the upper extremity during overhead throwing. Objective: The purpose of this study was to examine the effects of a hip abduction fatigue protocol on overhead throwing kinematics and hip passive r...

For kinematic studies of the shoulder, electromagnetic sensors are commonly placed on the humerus, scapula, and trunk. The trunk sensor is used to describe humeral and scapular kinematics with respect to the trunk. There are two common trunk sensor placements, the sternum or third thoracic vertebrae (T3). It is currently unclear if placement of the...

Study Design Cross-sectional. Background The scapular dyskinesis test (SDT) has demonstrated reliability and validity, but the utility for clinical decision-making is unclear. Objectives Characterize the prevalence of scapular dyskinesis in participants with and without shoulder pain, and to determine the influence of blinding to the presence of sh...

Study design: Cross-sectional cohort. Introduction: Tendon collagen organization can be estimated by peak spatial frequency radius (PSFR) on ultrasound images. Characterizing PSFR can define the contribution of collagen disruption to shoulder symptoms. Purpose of the study: The purpose of this was to characterize the (1) supraspinatus tendon P...

Background: Throwing requires proper stability and orientation of the pelvis and scapula for efficient energy transfer during pitching. Fatigue of the pelvis and scapular musculature throughout the course of a game can impair pitching performance, and place excessive demands on the throwing arm leading to injury. The purpose of this study was to e...

The purpose of this study was to examine the effects of game exposure on pitchers and catchers' hip and glenohumeral range of motion (ROM), isometric strength, and vertical jump performance and power. Five college female softball pitchers (174.24 ± 7.53 cm; 82.10 ± 11.27 kg; 20 ± 1.82 years) and four catchers (165.10 ± 9.04 kg; 68.61 ± 3.87 cm; 20...

Background and purpose: Range of motion deficits at the hip and glenohumeral joint (GHJ) may contribute to the incidence of injury in softball players. With injury in softball players on the rise, softball related studies in the literature are important. The purpose of this study was to examine hip and GHJ passive range of motion (PROM) patterns i...

The purpose of this study was to examine activations of selected scapular stabilizing musculature while performing an overhead throw with a hold (not releasing the ball) in two different throwing positions—standing with a crow hop and kneeling on the ipsilateral knee. Surface electromyography was used to examine activations of throwing side lower t...

Shoulder injuries are prevalent in the sport of team handball however no guidelines currently exist in the implementation of an interval throwing protocol for players returning from an upper extremity injury. These guidelines exist for the sport of baseball but team handball may present additional challenges due to greater ball mass that must be ac...

Team handball is a popular sport worldwide that requires numerous throws to be made throughout the course of a game. Because of the upper extremity demands of repetitive throwing, it is possible that fatigue can alter the mechanics of a shot. The purpose of this study was to determine the influence of localised fatigue on jump shot kinematics and k...

Proper utilization of the kinetic chain allows for efficient kinetic energy transfer from the proximal segments to the distal segments. The aims of this study were to describe muscle activations in four kinetic chain pre-throwing exercises and compare these muscle activations to three traditional resistance-band exercises.Twenty-six healthy college...

Background: With shoulder pain and injury on the rise in overhead athletes, clinicians are often examining preventative exercises to address functional abnormalities. Because shoulder impingement is prevalent in overhead athletes, much focus is on scapular stability and the function of the stabilizing force couple of the upper and lower trapezius...

Background: Aerobic fatigue from running may contribute to altered kinematics and as a result the possibility of injury exists. The purpose of this study was to examine the effects of aerobic fatigue on jump shot kinematics in team handball players. Methods: Ten male team handball players (23.60 ± 3.06 years; 184.68 ± 8.78 cm; 84.76 ± 9.23 kg) volu...

The overhead throwing motion requires the coordination of efficient segmental actions between the lower and upper extremity. The complexity of the overhead throwing motion, especially in pitching, may be affected by restriction in lower extremity range of motion [ROM]. The purpose of this study was to determine the relationship between lower extrem...

The purpose of this study was to determine the relationship between gluteal muscle activation and pelvis and trunk kinematics when catchers throw to second base. Forty-two baseball and softball catchers (14.74 ± 4.07 years; 161.85 ± 15.24 cm; 63.38 ± 19.98 kg) participated. Muscle activity of the bilateral gluteus maximus and medius were analyzed a...

The purpose of this study was to examine knee valgus in drop landings during three different footwear conditions and to examine the ground reaction forces exhibited during the drop landing in the three different footwear conditions. Sixteen male and female Reserve Officer Training Corps (ROTC) university undergraduate cadets (21 +/- 3 yrs, 79 +/- 1...

The aims of the present study were to examine quantitatively ground reaction forces, kinematics, and muscle activations during the windmill softball pitch, and to determine relationships between knee valgus and muscle activations, ball velocity and muscle activation as well as ball velocity and ground reaction forces. It was hypothesized that there...

Strength deficits in the quadriceps and hamstrings have been linked to several lower extremity injuries. The most common protocol used in testing for these deficits is isokinetic strength testing, which is both costly and time consuming. Therefore, the purpose of this study was to employ common vertical and horizontal power field tests to identify...

Fast-pitch softball has become an increasingly popular sport for female athletes. There has been little research examining the windmill softball pitch in the literature. The purpose of this study was to describe the muscle activation patterns of 3 upper extremity muscles (biceps, triceps, and rhomboids [scapular stabilizers]) and 2 lower extremity...