Gordon L Warren

Gordon L Warren
Georgia State University | GSU · Department of Physical Therapy

PhD

About

186
Publications
190,421
Reads
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8,109
Citations
Introduction
My most recent research efforts have focused on: 1) how cellular- and molecular-level inflammatory processes modulate the functional recovery following traumatic and exercise/work-induced musculoskeletal injuries, 2) how aging and loss of estrogen in females modulate muscle strength and recovery from traumatic muscle injury, and 3) how adjacent tissues (i.e., muscle and bone) affect the other’s recovery from traumatic wounds mimicking those occurring on the battlefield. These studies have involved both human and rodent models, including in vitro and in vivo muscle models.
Additional affiliations
July 2005 - present
Georgia Institute of Technology
Position
  • Adjunct Professor
August 1998 - June 2005
Georgia State University
Position
  • Professor (Associate)
April 1993 - July 1998
Texas A&M University
Position
  • Research Associate
Education
September 1986 - December 1989
University of Georgia
Field of study
  • Exercise Physiology
August 1984 - May 1986
Massachusetts Institute of Technology
Field of study
  • Biomedical Engineering / Radiological Sciences
September 1976 - June 1980
Georgia Institute of Technology
Field of study
  • Nuclear Engineering

Publications

Publications (186)
Article
Full-text available
Our objective was to perform a systematic review and meta-analysis of the research literature assessing the effect of caffeine ingestion on maximal voluntary contraction (MVC) strength and muscular endurance. Thirty-four relevant studies between 1939 and 2008 were included in the meta-analyses of caffeine's effects on MVC strength (n = 27 studies)...
Article
A primary feature of skeletal muscle lacking the protein dystrophin, as occurring in Duchenne muscular dystrophy, is a hypersensitivity to contraction-induced strength loss. We tested the hypothesis that the extensive strength loss results from an impairment in the electrophysiological function of the plasmalemma, specifically impaired action poten...
Article
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Background: An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first three days post-injury. Objective: The objective of this analysis was to conduct a systematic review and meta-analysis of the research lit...
Article
Key points: The female hormone oestrogen may protect muscle from injury by reducing inflammation but this is debatable. In this study, the inflammatory response of injured muscle from oestrogen-replete mice was comprehensively compared to that from oestrogen-deficient mice. We show that oestrogen markedly promotes movement of neutrophils, an infla...
Article
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Weakness and atrophy are key features of Duchenne muscular dystrophy (DMD). Dystrophin is one of the many proteins within the dystrophin glycoprotein complex (DGC) that maintains plasmalemmal integrity and cellular homeostasis. The dystrophin-deficient mdx mouse is also predisposed to weakness, particularly when subjected to eccentric (ECC) contrac...
Article
Purpose: Although quadriceps weakness after ACL reconstruction (ACLR) is well documented, the magnitude of reported weakness varies considerably. Such variation raises the possibility that certain patients may be more susceptible to quadriceps weakness after ACLR. This meta-analysis identified factors explaining between-study variability in quadri...
Article
Introduction Clinical trials addressing treatments for Duchenne muscular dystrophy (DMD) require reliable and valid measurement of muscle contractile function across all disease severity levels. This work aimed to evaluate a protocol combining voluntary and evoked contractions to measure strength and excitability of wrist extensor muscles, for safe...
Article
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Volumetric muscle loss (VML) injuries after extremity trauma results in an important clinical challenge often associated with impaired healing, significant fibrosis, and long-term pain and functional deficits. While acute muscle injuries typically display a remarkable capacity for regeneration, critically sized VML defects present a dysregulated im...
Article
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The purpose of this systematic review and meta-analysis was to determine if raising grandchildren is related to diminished mental health well-being in custodial grandparents compared to contemporaries who are not raising grandchildren. Relevant studies were identified via comprehensive literature searches of electronic databases. We included six st...
Article
The actions of selective estrogen receptor modulators are tissue dependent. The primary objective of the current study was to determine the tissue selective effects of bazedoxifene (BZA) on the musculoskeletal system of ovariectomized (OVX) female mice, focusing on strengths of muscle-bone pairs in the lower hindlimb. Treatment with BZA after ovari...
Article
BACKGROUND: While extreme changes in body position (e.g., standing vs. sitting) have been shown to affect knee extensor strength, little is known regarding how less extreme changes in body position affect knee extensor strength and activation. OBJECTIVE: This study evaluated the effect of four seated positions on the maximum voluntary isometric con...
Article
C-type natriuretic peptide (CNP) activation of guanylyl cyclase (GC)-B, also known as NPR2, stimulates cGMP synthesis and bone elongation. CNP activation requires the phosphorylation of multiple GC-B residues and dephosphorylation inactivates the receptor. GC-B7E/7E knockin mice, expressing a glutamate-substituted, “pseudophosphorylated,” form of G...
Article
Objective To examine whether BMI impacts the outcomes of mechanically ventilated patients. Methods Data was collected retrospectively among patients involved in motor vehicle accidents in intensive care at a major trauma center in Atlanta, GA. Patients were categorized into five BMI groups: underweight (BMI < 18.5), normal weight (BMI of 18.5-24.9...
Article
Objective(s): Stroke is a leading causes of long-term disability[1], often requiring rehabilitation to regain function[2]. While no consensus exists on how to optimize rehabilitation features, i.e. dose[3,4], evidence suggests a positive dose-response relationship with increased scheduled time and outcome[3,4,5]. Unfortunately, scheduled time[5], m...
Article
Increased demands associated with caregiving may lead to deleterious physical and mental health outcomes. Caregiving has proven to have consequences that affect both physical and psychological well-being. The purpose of this systematic review and meta-analysis was to assess the effects of exercise training on the mental and physical health of careg...
Article
Our goal was to understand the impact of regenerative therapies on the functional capacity of skeletal muscle following volumetric muscle loss (VML) injury. An extensive database search (e.g., PubMed, Cochrane Library, ClinicalTrials.gov) was conducted up through January 2019 to evaluate: "In humans or animals with VML injury, is treatment better t...
Article
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Purpose: Muscle that lacks dystrophin, as in the mdx mouse, has a heightened sensitivity to eccentric (ECC) contraction-induced strength loss, but an enhanced rate of recovery. However, the timeline and mechanisms underlying why mdx muscle recovers quicker has yet to be determined. We used an electromyographic (EMG) approach to analyze plasmalemma...
Article
Objective: This study examined the effects of reduced and elevated weight bearing on post-traumatic osteoarthritis (PTOA) development, locomotor joint kinematics, and degree of voluntary activity in rats following medial meniscal transection (MMT). Design: Twenty-one adult rats were subjected to MMT surgery of the left hindlimb and then assigned...
Conference Paper
Full-text available
PURPOSE: Dystrophin is responsible for maintaining plasmalemmal integrity and cellular homeostasis. A key feature of skeletal muscle that lacks dystrophin, as in the mdx mouse model for Duchenne muscular dystrophy (DMD), is a heightened sensitivity to eccentric (ECC) contraction-induced strength loss. However, the mechanisms responsible for the exa...
Article
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Purpose Post-tetanic potentiation (PTP) is the enhancement of twitch force following tetanic stimulation and is an important component when studying skeletal muscle physiology and plasticity. Mechanistically, it is plausible that PTP could be associated with an increase in fiber excitability and/or any event following sarcoplasmic reticulum (SR) ca...
Article
Brandenberger, KJ, Warren, GL, Ingalls, CP, Otis, JS, and Doyle, JA. Downhill running impairs activation and strength of the elbow flexors. J Strength Cond Res 35(8): 2145-2150, 2021-The purpose of this study was to determine if knee extensor injury induced by 1 hour of downhill running attenuated force production in the elbow flexors. Subjects com...
Article
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Caffeine (CAF) and carbohydrate (CHO) ingestion delay fatigue during prolonged exercise; however, this is primarily documented in endurance trained (ET) athletes. Our purpose was to determine if these ergogenic aids are also effective to improve exercise tolerance in age-matched sedentary (SED) adults. Using a double-blind crossover design, ET and...
Article
INTRODUCTION The causes of degenerative rotator cuff (RTC) tears are unclear but certain acromion morphology may contribute. This study's objective was to determine using a systematic review and meta‐analysis the association of acromion type and acromial index with the prevalence of RTC tears. MATERIALS AND METHODS Six databases were searched elec...
Article
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Background: Volumetric muscle loss (VML) injuries occur due to orthopaedic trauma or the surgical removal of skeletal muscle and result in debilitating long-term functional deficits. Current treatment strategies do not promote significant restoration of function; additionally appropriate evidenced-based practice physical therapy paradigms have yet...
Article
BACKGROUND: There is debate as to whether the use of nonsteroidal anti-inflammatory drugs (NSAIDs) is beneficial after acute skeletal muscle injury. Some studies have suggested that NSAID use may be detrimental to injured muscle. PURPOSE: To determine whether NSAID use affects recovery from skeletal muscle injury as assessed by strength loss, soren...
Article
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Caffeine (CAF) and small amounts of carbohydrate (CHO) ingested or simply exposed to the oral cavity appear to delay fatigue during prolonged exercise, possibly through central nervous system mechanisms. However, this has been primarily documented in endurance trained (ET) athletes. PURPOSE: To determine if: 1) CAF and/or a low dose of CHO (equival...
Article
High velocity impact injuries can often result in loss of large skeletal muscle mass, creating defects devoid of matrix, cells, and vasculature. Functional regeneration within these regions of large volumetric muscle loss (VML) continues to be a significant clinical challenge. Large cell-seeded, space-filling tissue engineered constructs that may a...
Article
The anomalous distal musculotendinous junction of the fibularis brevis muscle has been hypothesized to contribute to the development of longitudinal fibularis brevis tendon tears. Specifically, the mass effect of the low-lying fibularis brevis muscle belly was thought to increase the pressure on the superior peroneal retinaculum and increase the pr...
Article
Although most ACL injury prevention programmes encourage greater hip and knee flexion during landing, it remains unknown how this technique influences tibiofemoral joint forces. We examined whether a landing strategy utilising greater hip and knee flexion decreases tibiofemoral anterior shear and compression. Twelve healthy women (25.9 ± 3.5 years)...
Article
Volumetric muscle loss (VML) injuries present a large clinical challenge with a significant need for new interventions. While there have been numerous reviews on muscle injury models, few have critically evaluated VML models. The objective of this review is to discuss current preclinical models of VML in terms of models, analytical outcomes, and th...
Article
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HOUSLEY, Stephen N.1, James E. LEWIS2, and Deon L. OMPSON 1. 1Department of Physical Therapy, Georgia State University, Atlanta, GA 30302, USA; 2Department of Physical Therapy, Brenau University, Gainesville, Georgia, 30501, USA. Proximal peroneus brevis muscle belly insertion and the prevalence of longitudinal split tendon: a cadaveric study. INT...
Article
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Strength of a muscle group is determined by its physiological cross-sectional area and one’s ability to activate the muscle group. Injury and disuse are associated with a decreased ability to maximally activate a muscle group. Clinical orthopedic measures such as manual muscle testing may provide an indication of muscle strength but no direct insig...
Article
Because caffeine ingestion has been found to increase muscle strength, our aim was to determine if caffeine when combined with other potential ergogenic ingredients, such as those in commercial energy drinks, would have a similar effect. Fifteen young healthy subjects were used in a double-blind, repeated measures experimental design. Each subject...
Article
Background: Indirect calorimetry measured via the traditional indirect calorimeter is considered the "gold standard" for determining resting metabolic rate (RMR). Portable devices for assessing RMR are a less expensive option for measuring RMR in the clinical setting. This pilot study tested the reliability and validity of a portable device for me...
Article
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AIM: To determine if the addition of hip-strengthening exercises decreases pain and improves function in patients with patellofemoral pain syndrome. METHODS: The authors completed a systematic review searching eight databases (i.e. , PubMed, Cochrane, CINHAL, MEDLINE, SportsDiscus, EMBASE, APTA Hooked on Evidence, and PEDro). Two independent review...
Conference Paper
Full-text available
Proximal peroneus brevis muscle insertion and the prevalence of split tendons: a cadaveric study. INTRODUCTION. The anomalous distal musculotendinous (MT) junction of the peroneus brevis (PB) muscle has been hypothesized to contribute to the development of longitudinal PB tendon tears. Specifically, mass action of the PB muscle belly was thought to...
Article
Full-text available
Aging-induced declines in muscle size and quality are thought to contribute to catabolic alterations in bone, but changes in bone with age also profoundly alter its response to muscle-derived stimuli. This review provides an overview of some of the alterations that occur in muscle and bone with aging, and discusses the cellular and molecular mechan...
Article
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Bone loss due to age and disuse contributes to osteoporosis and increases fracture risk. It has been hypothesized that such bone loss can be attenuated by modulation of the C-C chemokine receptor 2 (CCR2) and/or its ligands. The objectives of this study were to examine the effects of genetic elimination of CCR2 on cortical and trabecular bones in t...
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The objective of the study was to determine if low intensity, high frequency vibration training impacted the musculoskeletal system in a mouse model of Duchenne muscular dystrophy, relative to healthy mice. Three-week old wildtype (n = 26) and mdx mice (n = 22) were randomized to non-vibrated or vibrated (45 Hz and 0.6 g, 15 min/d, 5 d/wk) groups....
Article
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Objective: To systematically examine the research literature on the effectiveness of constraint-induced movement therapy on improving arm function in children with cerebral palsy, and to assess the association between the study effect size and the characteristics of the patients and intervention protocol. Data sources: A systematic literature se...
Article
Severe injuries to the extremities often result in muscle trauma and, in some cases, significant volumetric muscle loss (VML). These injuries continue to be challenging to treat, with few available clinical options, a high rate of complications, and often persistent loss of limb function. To facilitate the testing of regenerative strategies for ske...
Article
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Extremity injuries involving large bone defects with concomitant severe muscle damage are a significant clinical challenge often requiring multiple treatment procedures and possible amputation. Even if limb salvage is achieved, patients are typically left with severe short and long-term disabilities. Current pre-clinical animal models do not adequa...
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The purpose of this study was to determine the extent to which prednisolone treatment and restricted physical activity caused deleterious changes in inherently compromised mdx bone. Four week-old male mdx mice (n=36) were treated for 8-wk either with or without prednisolone (0.8-1.3 mg/kg/d) and were housed in traditional or small cages (restricted...
Article
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An estimated 70% of people will experience low back pain at some point in their lives, and recurrence rates can be as high as 85%. Recent studies suggest that yoga – a widely practiced physical/mental discipline – may relieve back pain and reduce functional disability. The objective of this study was to conduct a systematic review and meta-analysis...
Article
Full-text available
The objective of this study was to determine the functional recovery and adaptation of dystrophic muscle to multiple bouts of contraction-induced injury. Because lengthening (i.e., eccentric) contractions are extremely injurious for dystrophic muscle, it was considered that repeated bouts of such contractions would exacerbate the disease phenotype...
Article
Full-text available
Many aspects of skeletal muscle regeneration are now considered to be controlled by the innate immune system, specifically macrophages, but the mechanisms for activation and modulation of the innate immune system during injury are not well understood. We analyzed the expression of toll-like receptors (TLRs) and adenosine receptors during traumatic...