Karl B. Fields
University of North Carolina at Greensboro
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Current Sports Medicine Reports | 2010
Karl B. Fields; Jeannie C. Sykes; Katherine M. Walker; Jonathan C. Jackson
Evidence for preventive strategies to lessen running injuries is needed as these occur in 40%-50% of runners on an annual basis. Many factors influence running injuries, but strong evidence for prevention only exists for training modification primarily by reducing weekly mileage. Two anatomical factors - cavus feet and leg length inequality - demonstrate a link to injury. Weak evidence suggests that orthotics may lessen risk of stress fracture, but no clear evidence proves they will reduce the risk of those athletes with leg length inequality or cavus feet. This article reviews other potential injury variables, including strength, biomechanics, stretching, warm-up, nutrition, psychological factors, and shoes. Additional research is needed to determine whether interventions to address any of these will help prevent running injury.
Current Sports Medicine Reports | 2006
Ryan Modlinski; Karl B. Fields
Over the past several decades we have seen an increase in the prevalence of anabolic steroid use by athletes. Because use of anabolic steroids is illicit, much of our knowledge of their side effects is derived from case reports, retrospective studies, or comparisons with studies in other similar patient groups. It has been shown that high-dose anabolic steroids have an effect on lowering high-density lipoprotein, increasing low-density lipoprotein, and increasing the atherogenic-promoting apolipoprotein A. Steroid abuse can also be hepatotoxic, promoting disturbances such as biliary stasis, peliosis hepatis, and even hepatomas, which are all usually reversible upon discontinuation. Suppression of the hypothalamic adrenal axis can also lead to profound adrenal changes that are also reversible with time. Although rare, renal side effects have also been documented, leading to acute renal failure and even Wilms’ tumors in isolated cases. Much of our knowledge of these potentially severe but usually limited side effects is confounded by use of combinations of different steroid preparations and by the concomitant use with other substances. Physicians must target their efforts at counseling adolescents and other athletes about the potential harms of androgenic anabolic steroids and the legal options to improve strength and performance.
British Journal of Sports Medicine | 2016
Jonathan A. Drezner; Francis G. O'Connor; Kimberly G. Harmon; Karl B. Fields; Chad A. Asplund; Irfan M. Asif; David E. Price; Robert J. Dimeff; David T. Bernhardt; William O. Roberts
Cardiovascular screening in young athletes is widely recommended and routinely performed prior to participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for cardiovascular screening in athletes remains an issue of considerable debate. At the centre of the controversy is the addition of a resting ECG to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation cardiovascular screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcome-based evidence at this time precludes AMSSM from endorsing any single or universal cardiovascular screening strategy for all athletes, including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate cardiovascular screening strategy unique to their athlete population, community needs and resources. The decision to implement a cardiovascular screening programme, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physicians assessment in the context of an emerging evidence base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. AMSSM is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.
Current Sports Medicine Reports | 2009
Spencer T. Copland; John S. Tipton; Karl B. Fields
Hamstring tears are exceedingly common in a variety of athletic populations and contribute to a significant amount of morbidity and time lost from sport. Many modifiable and nonmodifiable risk factors have been identified with hamstring injury. There is strong evidence that Nordic hamstring exercises can decrease the risk of hamstring injury, limited evidence that sports specific anaerobic interval training and isokinetic strengthening can reduce injury rates, and limited evidence that daily static stretching after injury can increase recovery rate. The majority of medical, surgical, and rehabilitative intervention studies have limitations based on the total number of hamstring injuries included in a given study, reliance on retrospective cohort studies, and conclusions based on case series that limit the utility of the information. Most do not provide a level of evidence greater than expert opinion.
Current Sports Medicine Reports | 2011
Karl B. Fields
Running injuries are common. Recently the demographic has changed, in that most runners in road races are older and injuries now include those more common in master runners. In particular, Achilles/calf injuries, iliotibial band injury, meniscus injury, and muscle injuries to the hamstrings and quadriceps represent higher percentages of the overall injury mix in recent epidemiologic studies compared with earlier ones. Evidence suggests that running mileage and previous injury are important predictors of running injury. Evidence-based research now helps guide the treatment of iliotibial band, patellofemoral syndrome, and Achilles tendinopathy. The use of topical nitroglycerin in tendinopathy and orthotics for the treatment of patellofemoral syndrome has moderate to strong evidence. Thus, more current knowledge about the changing demographics of runners and the application of research to guide treatment and, eventually, prevent running injury offers hope that clinicians can help reduce the high morbidity associated with long-distance running.
Clinical Journal of Sport Medicine | 2016
Jonathan A. Drezner; Francis G. O'Connor; Kimberly G. Harmon; Karl B. Fields; Chad A. Asplund; Irfan M. Asif; David E. Price; Robert J. Dimeff; David T. Bernhardt; William O. Roberts
ABSTRACTCardiovascular (CV) screening in young athletes is widely recommended and routinely performed before participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for CV screening in athletes remains an issue of considerable debate. At the center of the controversy is the addition of a resting electrocardiogram (ECG) to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation CV screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcomes-based evidence at this time precludes AMSSM from endorsing any single or universal CV screening strategy for all athletes including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate CV screening strategy unique to their athlete population, community needs, and resources. The decision to implement a CV screening program, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physicians assessment in the context of an emerging evidence base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. American Medical Society for Sports Medicine is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.
Current Sports Medicine Reports | 2016
Jonathan A. Drezner; Francis G. O'Connor; Kimberly G. Harmon; Karl B. Fields; Chad A. Asplund; Irfan M. Asif; David E. Price; Robert J. Dimeff; David T. Bernhardt; William O. Roberts
Cardiovascular screening in young athletes is widely recommended and routinely performed prior to participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for cardiovascular screening in athletes remains an issue of considerable debate. At the center of the controversy is the addition of a resting electrocardiogram (ECG) to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation cardiovascular screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcomes-based evidence at this time precludes AMSSM from endorsing any single or universal cardiovascular screening strategy for all athletes, including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate cardiovascular screening strategy unique to their athlete population, community needs, and resources. The decision to implement a cardiovascular screening program, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physician’s assessment in the context of an emerging evidence-base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. AMSSM is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.
Current Sports Medicine Reports | 2012
Karl B. Fields; Thomas J. Thekkekandam; Sara Neal
Wheezing is a commonly encountered complaint by patients seen in sports medicine practice. Wheezes are a continuous musical sound heard best on expiration and can originate from one or more of several defined anatomical locations in the human airway. While common causes of wheezing include exercise-induced bronchoconstriction, postnasal drip, and asthma, wheezing also follows specific respiratory infections and can persist for months after the onset of symptoms. Abnormal lung physiology following pneumonia can persist for decades. These postinfectious pulmonary changes affect the ability of athletes to return to sports. In addition to history and physical examination, diagnosis may require pulmonary function testing and exercise challenge testing. The cornerstone to management is an accurate diagnosis and using lifestyle and pharmacologic intervention. Return to play should be gradual and allowed only after individuals demonstrate adequate pulmonary capacity to meet the demands of their sport. Providers also should be aware of governing body regulations regarding treatments and required therapeutic use exemptions.
Clinical Journal of Sport Medicine | 2011
Timothy J Von Fange; Karl B. Fields; James M Daniels; David M. Harsha
Dear Editor-in-Chief: Drs Borjesson and Dellborg present evidence to support mandating an electrocardiogram (ECG) as part of the preparticipation examination. The authors state, ‘‘the scientific reasons for including the ECG in pre-participation screening look clear and undisputable.’’ However, their arguments leave many key points and questions unanswered. One key point is the frequency of screening. In a cost-effectiveness analysis cited by the authors, the use of ECG plus history and physical will cost 42 000 USD per life-year saved compared with a cardiovascular-focused history and physical alone. This analysis, which uses a decision-based model to generate its output as opposed to a study population, uses a single ECG screening. The same analysis goes on to state ‘‘that annual screening of any kind, or extending screening to all middle school and high school students, is highly unlikely to be cost-effective in reduction of sudden cardiac death.’’ The appropriate timing of a single ECG screen and the liability of a negative result in which the phenotype has not yet been expressed remain unanswered. In addition, the incidence of sudden cardiac death (SCD) in athletes seems to be a moving target. In a review discussing the incidence and etiology previously authored by Dr Borjesson, the incidence of SCD in US high school and college-aged athletes is cited to be 0.5/100 000 participants per year. However, in this article, Dr Borjesson cites his own review and provides a number of 1 to 3/100 000 participants per year. Variability of this degree in the incidence of SCD will have dramatic effects on models analyzing the effectiveness of any screening program. In summary, it is our belief that the scientific reasoning for ECG screening is far from ‘‘clear and undisputable.’’ Further analysis that clearly defines the incidence of SCD, timing and interpretation of screening interventions, and target populations are necessary before mandating such interventions.
Current Sports Medicine Reports | 2016
Karl B. Fields; Michael D. Rigby