Francis G. O'Connor

National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses.

OBJECTIVE To present best-practice recommendations for the prevention, recognition, and treatment of exertional heat illnesses (EHIs) and to describe the relevant physiology of thermoregulation. BACKGROUND Certified athletic trainers recognize and treat athletes with EHIs, often in high-risk environments. Although the proper recognition and successful treatment strategies are well documented, EHIs continue to plague athletes, and exertional heat stroke remains one of the leading causes of sudden death during sport. The recommendations presented in this document provide athletic trainers and allied health providers with an integrated scientific and clinically applicable approach to the prevention, recognition, treatment of, and return-to-activity guidelines for EHIs. These recommendations are given so that proper recognition and treatment can be accomplished in order to maximize the safety and performance of athletes. RECOMMENDATIONS Athletic trainers and other allied health care professionals should use these recommendations to establish onsite emergency action plans for their venues and athletes. The primary goal of athlete safety is addressed through the appropriate prevention strategies, proper recognition tactics, and effective treatment plans for EHIs. Athletic trainers and other allied health care professionals must be properly educated and prepared to respond in an expedient manner to alleviate symptoms and minimize the morbidity and mortality associated with these illnesses.

Functional Movement Screening:Predicting Injuries in Officer Candidates

PURPOSE Functional movement screening (FMS) is a musculoskeletal assessment method that incorporates seven movements and yields an overall score based on movement quality. The objectives of this study were to document the distribution of scores and to determine whether FMS scores could predict injury in a large military cohort. METHODS A cohort of 874 Marine officer candidates were recruited, consented, completed demographic questionnaires, and had FMS performed during medical in-processing. Candidates were enrolled in either long-cycle (LC: 68 d; n = 427) or short-cycle (SC: 38 d; n = 447) training and followed up for injuries occurring in training. RESULTS The mean FMS score (score range = 0-21) among all candidates was 16.6 ± 1.7; approximately 10% of candidates had FMS scores ≤14. A score of ≤14 on the FMS predicted any injury with a sensitivity of 0.45 and a specificity of 0.71 and serious injury with a sensitivity of 0.12 and a specificity of 0.94. Both LC and SC cohorts demonstrated higher injury risk among candidates who had scores ≤14 compared with those with scores >14 (LC: risk ratio (RR) = 1.65, 95% confidence interval = 1.05-2.59, P = 0.03; SC: RR = 1.91, 95% confidence interval = 1.21-3.01, P < 0.01). Overall, 79.8% of persons with scores ≤14 were in the group with fitness scores <280 (/300), whereas only 6.6% of candidates in the group with fitness scores ≥280 had scores ≤14. CONCLUSIONS This was the first large-scale study performed in an active-duty military cohort to examine the utility of FMS during medical in-processing. Further work is warranted to evaluate FMS and the potential for injury prediction and prevention.

American college of sports medicine Roundtable on exertional heat stroke - Return to duty/return to play: Conference proceedings

On October 22-23, 2008, an ACSM Roundtable was convened at the Uniformed Services University (Bethesda, MD) to discuss return-to-play or return-to-duty for people who have experienced exertional heat illness (EHI) and to develop consensus-based recommendations. The conference assembled experts from the civilian sports medicine community and the Department of Defense to discuss relevant EHI issues, such as potential long-term consequences, the concept of thermotolerance, and the role of thermal tolerance testing in return-to-play decisions. Although the group was unable to move forward with new consensus recommendations, they clearly documented critical clinical concerns and scientific questions, including the following: 1) no uniform core definitions of EHI; 2) limited validated criteria to assess recovery from exertional heat stroke (EHS); and 3) inadequate ability to predict who may be predisposed to a subsequent heat injury after EHS. Areas of potential future research are identified.

Consortium for Health and Military Performance and American College of Sports Medicine Consensus Paper on Extreme Conditioning Programs in Military Personnel

A potential emerging problem associated with increasingly popularized extreme conditioning programs (ECPs) has been identified by the military and civilian communities. That is, there is an apparent disproportionate musculoskeletal injury risk from these demanding programs, particularly for novice participants, resulting in lost duty time, medical treatment, and extensive rehabilitation. This is a significant and costly concern for the military with regard to effectively maintaining operational readiness of the Force. While there are certain recognized positive aspects of ECPs that address a perceived and/or actual unfulfilled conditioning need for many individuals and military units, these programs have limitations and should be considered carefully. Moreover, certain distinctive characteristics of ECPs appear to violate recognized accepted standards for safely and appropriately developing muscular fitness and are not uniformly aligned with established and accepted training doctrine. Accordingly, practical solutions to improve ECP prescription and implementation and reduce injury risk are of paramount importance.

Exercise-associated collapse: an evidence-based review and primer for clinicians

Exercise-associated collapse (EAC) commonly occurs after the completion of endurance running events. EAC is a collapse in conscious athletes who are unable to stand or walk unaided as a result of light headedness, faintness and dizziness or syncope causing a collapse that occurs after completion of an exertional event. Although EAC is perhaps the most common aetiology confronted by the medical provider attending to collapsed athletes in a finish-line tent, providers must first maintain vigilance for other potential life-threatening aetiologies that cause collapse, such as cardiac arrest, exertional heat stroke or exercise-associated hyponatraemia. Previously, it has been believed that dehydration and hyperthermia were primary causes of EAC. On review of the evidence, EAC is now believed to be principally the result of transient postural hypotension caused by lower extremity pooling of blood once the athlete stops running and the resultant impairment of cardiac baroreflexes. Once life-threatening aetiologies are ruled out, treatment of EAC is symptomatic and involves oral hydration and a Trendelenburg position – total body cooling, intravenous hydration or advanced therapies is generally not needed.

Return to physical activity after exertional rhabdomyolysis.

Exertional rhabdomyolysis (ER) is a condition characterized by muscle pain, swelling, and weakness following some exertional stress, with or without concomitant heat stress. Athletes who experience ER often present to the emergency department, the training room, or the physicians office seeking guidance and care for this condition, often feeling it is simply normal delayed onset muscle soreness. The astute clinician must perform a thorough history and focused exam, in addition to ordering a serum creatine kinase (CK) and urinalysis. In this clinical setting, a CK equal to or greater than five times normal or a urine dipstick testing positive for blood with no demonstrable red blood cells upon microscopic assessment confirms the diagnosis. A urine or serum myoglobin is more definitive when expeditiously available. After treatment for ER, the provider must risk-stratify the athlete for risk of recurrence, consider further testing, and make the difficult decision on when, if, and under what conditions the athlete can safely return to play.

Managing Overuse Injuries: A Systematic Approach

Cumulative, repetitive microtrauma can cause tissue damage that leads to overuse injuries, which constitute a large share of sports-related disorders. The authors explain their five-step approach to treating overuse injuries: establishing a pathoanatomic diagnosis, controlling inflammation, promoting healing, increasing fitness, and controlling tissue abuse. The case of a 28-year-old male runner with heel pain demonstrates their management of overuse injuries.

AMSSM Position Statement on Cardiovascular Preparticipation Screening in Athletes: current evidence, knowledge gaps, recommendations and future directions

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.

Cold-water dousing with ice massage to treat exertional heat stroke: a case series.

INTRODUCTION We sought to determine the rate of cooling via a novel water ice therapy (WIT) as an alternative to cold-water immersion for the acute treatment of exertional heat stroke (EHS). METHODS Observations were made at the 2004-2008 Marine Corps Marathons (mean +/- SD: 16.3 +/- 4.9 degrees C dry bulb, 32 +/- 6% RH). Nine (seven men, two women) EHS patients (33 +/- 6 yr of age; 268 +/- 54 min average race time for six who finished) were observed during on-site treatment. Patients were treated while lying supine on a porous stretcher resting on a tub filled with cold water (approximately 10-12 degrees C). Medical personnel monitored T(re), doused the patient with water and massaged major muscle groups with ice bags until T(re) decreased to 38.9 degrees C. Patients were not immersed in water. Serial T(re) and time were used to calculate cooling rates. RESULTS Final T(re) (39.12 +/- 0.63 degrees C) was significantly lower than initial T(re) (41.43 +/- 0.71 degrees C, P < 0.05). Cooling rates were 0.13 +/- 0.04 degrees C min(-1). The decrease in T(re) for the initial 6 min of WIT (0.38 +/- 0.13 degrees C) was significantly less than for the subsequent 6-min time period (1.31 +/- 0.34 degrees C, P < 0.001). Cooling rates for these time periods were significantly different (0.06 +/- 0.02 degrees C x min(-1) and 0.22 +/- 0.06 degrees C x min(-1), respectively, P < 0.05). Initial T(re) was not correlated with overall cooling rate (r = 0.434, P = 0.244), or total cooling time required (17 +/- 4 min; r = 0.207, P = 0.593). Survival rate was 100%. CONCLUSION WIT provided cooling rates that were 70% as effective as those published for cold-water immersion with 8 degrees C water (0.19 degrees C x min(-1)) and resulted in 100% patient survival.

Heat Tolerance Testing: Association Between Heat Intolerance and Anthropometric and Fitness Measurements

This study investigated associations between heat intolerance, as determined by performance on a heat tolerance test (HTT), and anthropometric measurements (body surface-to-mass ratio, percent body fat, body mass index, and waist circumference) and cardiorespiratory fitness (maximal oxygen uptake [VO2max]). Relationships between predictive variables and specific physiological measurements recorded during the HTT were examined. A total of 34 male and 12 female participants, recruited from the military community, underwent anthropometric measurements, a maximal aerobic exercise test, and a standardized HTT, which consisted of walking on a treadmill at 5 km/h at 2% grade for 120 minutes at 40°C and 40% relative humidity. VO2max negatively correlated with maximum core temperature (r = -0.30, p < 0.05) and heart rate (HR) (r = -0.48, p < 0.01) although percent body fat showed a positive correlation with maximum HR (r = 0.36, p < 0.05). VO2max was the only independent attribute that significantly influenced both the maximum HR and core temperature attained during HTT. Logistic regression analyses indicated that VO2max was the only independent parameter (OR = 0.89, p = 0.026) that significantly contributed to overall HTT performance. Low cardiorespiratory fitness was associated with heat intolerance, as defined by HTT performance, and can be addressed as a preventative measure for exertional heat illness. This study provides further evidence that the HTT can be an effective tool for assessment of thermoregulatory patterns.