Patricia A. Deuster

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.

Plasma Growth Hormone and Prolactin Responses to Graded Levels of Acute Exercise and to a Lactate Infusion

The effect of acute exercise at three graded intensities on plasma growth hormone (GH) and prolactin (PRL) concentrations was examined in three groups of healthy male volunteers. According to their training status these subjects were divided into untrained, moderately trained and highly trained. A clear response of GH to exercise was registered already at an intensity of 50% of maximal oxygen uptake (VO2max) with a maximal response at 70% VO2max and no further effect at 90% VO2max. In contrast, no PRL response was observed at 50% VO2max, a small PRL rise was seen at 70% VO2max and the highest response occurred at 90% VO2max. Basal and exercise-stimulated plasma GH and PRL concentrations were similar in the three groups tested at similar relative workloads, suggesting that physical training induces adaptive changes whereby higher absolute workloads induce similar hormonal and metabolic changes. To examine a potential causative role of lactate in inducing the GH and PRL responses, sodium L-lactate was infused intravenously to normal sedentary volunteers at doses producing plasma lactate concentrations within the range of those seen between 70 and 90% VO2max. This resulted in a significant elevation of plasma GH and PRL concentrations, which, however, were smaller than those obtained at an exercise-induced matched plasma lactate concentration. We conclude that physical training causes adaptive changes in highly trained runners so that identical GH and PRL responses to exercise are recorded at higher absolute workloads. Lactate may be involved in the exercise-induced GH and PRL response; however, it does not appear to play an exclusive role.

Depressive mood symptoms and fatigue after exercise withdrawal: the potential role of decreased fitness.

Objective: Depressive symptomatology is more prevalent among sedentary than physically active individuals. The present prospective study examines whether withdrawal of regular aerobic activity provokes depressive mood symptoms and fatigue, and to what extent reductions in fitness levels contribute to the development of these symptoms. Methods: Forty participants (mean age of 31.3 ± 7.5 years, 55% women) who exercised regularly (≥30 minutes aerobic exercise ≥3 times/week) were randomized to aerobic exercise withdrawal (n = 20) or to continue regular exercise (n = 20) for 2 weeks. Protocol adherence was documented using ambulatory actigraphy. Negative mood was measured with the Profile of Mood States (POMS), depressive symptoms with the Beck Depression Inventory–II (somatic and cognitive–affective components), and fatigue with the Multidimensional Fatigue Inventory (MFI). Fitness levels were documented by cycle ergometry testing. Results: Fatigue and somatic depressive symptoms emerged after 1 week of exercise withdrawal (p = .05) and subsequently predicted the development of cognitive–affective depressive symptoms at 2 weeks (&bgr; = 0.62; p = .046). Exercise withdrawal also resulted in increased negative mood (POMS; p ≤ .01), and this increase was correlated with decreases in fitness level (r = −0.36, p = .03). Decreased fitness was related to increased POMS fatigue (p = .003) when statistically adjusting for baseline fitness levels and group condition. Conclusion: Depressed mood and fatigue are commonly observed in individuals deprived of usual exercise activities, and the increase in fatigue may be partially mediated by reduced fitness levels. These findings may explain mood changes in response to short-term exercise withdrawal such as injuries and recovery from medical procedures that do not require full bedrest. BDI-II = Beck Depression Inventory–II; BMI = body mass index; HR = heart rate; MET = metabolic equivalent of task; MFI = Multidimensional Fatigue Inventory; POMS = Profile of Mood States; TMD = total mood disturbance; VO2max = maximum volume of oxygen that can be used per minute; index of maximal aerobic power.

Functional Movement Screen and Aerobic Fitness Predict Injuries in Military Training

PURPOSE This study investigated associations between injuries and individual components of the Marine Corps physical fitness test (PFT), self-reported exercise and previous injury history, and Functional Movement Screen (FMS) scores. METHODS A cohort of 874 men enrolled in either 6 wk (n = 447) or 10 wk (n = 427) of Marine Corps officer candidate training was recruited. They completed an exercise history questionnaire, underwent an FMS during medical in-processing, and completed the standardized PFT (pull-ups, abdominal crunch, and 3-mile run) within 1 wk of training. Injury data were gathered throughout training from medical records and classified into overuse, traumatic, and any injury. RESULTS Three-mile run time (RT) was the only PFT component predictive of injury: candidates with RT ≥20.5 min were 1.7 times (95% confidence interval = 1.29-2.31, P < 0.001) more likely to experience an injury compared with those with RT <20.5 min. Prior injury, frequency of general exercise and sport participation, and length of running history were predictive of any, overuse, and traumatic injuries, respectively. Combining slow RT and low FMS scores (≤14) increased the predictive value across all injury classifications: candidates scoring poorly on both tests were 4.2 times more likely to experience an injury. The pull-up to exhaustion test was related to four of the seven FMS tests and the only PFT test positively related to total FMS score, although correlations were generally low (r ≤ 0.11). CONCLUSION Slow RT was associated with increased injury risk, and combining poor RT and low FMS scores significantly increased the injury predictive value. Additional research is warranted to further clarify what combination of PFT and FMS tests are most suitable for predicting injuries.

Should triglycerides and the triglycerides to high-density lipoprotein cholesterol ratio be used as surrogates for insulin resistance?

The aims of the present study were to examine whether triglycerides (TG) and the triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C) could predict insulin resistance in healthy African Americans and whites. This cross-sectional study included 99 African American and 50 white men and women between 18 and 45 years of age with body mass indexes between 18.5 and 38.0 kg/m(2). Anthropometric measures were obtained; and overnight fasting blood was collected for TG, HDL-C, glucose, and insulin. Insulin resistance was defined by fasting insulin concentration of at least 13.13 microU/mL and homeostasis model assessment of insulin resistance (HOMA-IR) of at least 2.5. Receiver operating characteristic curves were used to analyze the data. African Americans and whites had comparable demographic and anthropometric measures. Fasting insulin was higher in African Americans (12.4 +/- 7.8 microU/mL) than whites (10.2 +/- 7.5 microU/mL), but HOMA-IR did not differ significantly (African Americans, 2.9 +/- 2.0; whites, 2.4 +/- 1.9). Triglycerides and TG/HDL-C were significantly lower in African Americans (TG, 68.2 +/- 43.3 mg/dL; TG/HDL-C, 1.8 +/- 2.1) compared with whites (TG, 105.4 +/- 55.2 mg/dL; TG/HDL-C, 2.8 +/- 1.8). Area under the receiver operating characteristic curves revealed that both TG and TG/HDL-C were acceptable markers of insulin resistance, as defined by fasting insulin concentration, in whites, 0.770 and 0.765, respectively, but poor predictors in African Americans, 0.633 and 0.651, respectively. Similarly, TG and TG/HDL-C were acceptable in predicting insulin resistance, as measured by HOMA-IR, in whites, 0.763 and 0.770, respectively, but poor in predicting HOMA-IR in African Americans, with areas of 0.625 and 0.639, respectively. In conclusion, the relationship between TG and TG/HDL-C with insulin resistance differs by ethnicity; and using TG and TG/HDL-C to predict insulin resistance in African Americans would not be appropriate.

Orthopedic history and examination in the etiology of overuse injuries.

Overuse injuries, and stress fractures in particular, afflict many runners and military recruits. This investigation sought to identify pretraining factors which may predispose to overuse injuries. Orthopedic and running history questionnaires and an orthopedic examination were administered to 505 trainees entering an intensive military training school. A novel method for evaluating ankle dorsiflexion was developed, and alignment measures, in units of centimeters rather than degrees, were obtained. Over 10% of the trainees were removed from the school for overuse-related injuries, and over half of these were tibial stress fractures. The incidence of clinically diagnosed stress fractures was 6.3%. No single orthopedic history question or combination of questions could discriminate between trainees who did or did not subsequently incur overuse injuries. Results from the running history indicated that those running 25 or more miles.wk-1 (mpw) had a significantly (P less than 0.027) lower incidence of stress fractures (3.0%) than those running 4 or fewer mpw over the previous year (11.5%). The orthopedic examination did not identify any predisposing alignment characteristics, perhaps due to the low incidence of overuse injuries. Population means are presented for future use in comparative studies.

Physiological and Psychological Fatigue in Extreme Conditions: Overtraining and Elite Athletes

This article will review relevant mechanisms and markers associated with overtraining syndrome (OTS), and discuss signs and symptoms, differential diagnosis, and current assessment tools for fatigue within the context of overtraining. The findings are drawn from original research and review articles referenced by PubMed and ScienceDirect databases. Sources were selected for their contributions to the current knowledge of biological, psychological, and molecular mechanisms. Data were reviewed for relevance to OTS and then evaluated against criteria that included significant OTS outcomes and findings. Information was systematically analyzed to identify patterns, dependencies, connections, and causal factors. Comparative analysis was confounded by inconsistent metrics, terminology, and variable methodology; potential biomarkers, treatment and prevention approaches, and future research directions are identified. Diagnosing OTS is difficult because underlying cause(s) are unknown; one must exclude other factors that degrade performance and mood status. Many studies are confounded by inadequate experimental designs, poor measures of performance, and different methods for characterizing OTS. OTS is complex because the demands of excessive training in combination with other biologic, psychological, and social stressors are difficult to quantify. However, changes in mood are always noted. Interrelations among dietary patterns; social, psychological and physiological profiles; and the neuroendocrine, immune, and central nervous systems are complex and not adequately elucidated.

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.

Neurohormonal and Inflammatory Hyper-Responsiveness to Acute Mental Stress in Depression

Depression is associated with dysregulated hypothalamic-pituitary-adrenal (HPA) axis function, overactivity of the sympathoadrenal system, and increased levels of inflammation markers. It is not known whether these biological processes are disproportionately elevated in response to acute negative emotional arousal by mental stress (MS). The present study investigates responses of neurohormones and inflammatory markers to MS in 14 clinically depressed (age: 42+/-10 years; 50% female) and 14 non-depressed control (age: 39+/-6 years; 50% female) participants. Heightened acute MS reactivity was documented in depressed participants (adrenocorticotropic hormone, rho=0.001; norepinephrine, rho=0.042; epinephrine, rho=0.039), and a delayed increase in cortisol was observed (rho=0.002). Inflammation markers increased more strongly in depressed versus non-depressed participants (IL-6, rho=0.027; tumor necrosis factor-alpha, rho=0.050; and recovery C-reactive protein, rho=0.003). It is concluded that depressed individuals display hyper-reactivity of neuroimmunological markers in response to acute negative emotions. This hyper-reactivity may serve a pathologic role in the elevated morbidity and mortality risk associated with depression.