The Use of Force Plate Vertical Jump Scans to Identify Special Warfare Trainees at Risk for Musculoskeletal Injury: A Large Cohort Study.

BACKGROUND: Vertical jump scans from commercially available force plate systems are increasingly used in military settings to screen for musculoskeletal injury (MSKI) risk. However, to date, no studies have determined the ability of these tools to identify tactical athletes at elevated risk for MSKI. PURPOSE: To (1) determine associations between scores from a force plate vertical jump test and the likelihood of experiencing an MSKI and to (2) establish the test-retest reliability of the output scores from the force plate system used. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 823 male Air Force Special Warfare trainees underwent force plate vertical jump screenings before entering an 8-week training course at US Air Force Special Warfare Training Wing. MSKI data were collected for the 8-week surveillance period for each trainee. Logistic regression analyses were used to identify associations between baseline force plate jump scores and the likelihood of MSKI (any region) or a lower extremity MSKI (significance level, P = .05). The test-retest portion of the study collected force plate output scores from 12 trainees performing 3 trials of the standard test procedures. The reliability of 5 output scores was assessed with intraclass correlation coefficients (ICCs) using a single rater. RESULTS: All force plate output scores demonstrated excellent test-retest reliability (ICC >0.90). Overall 308 (36.4%) trainees had an MSKI during the surveillance period. However, no significant associations were found between the proprietary force plate vertical jump scan output scores and the likelihood of experiencing either an MSKI or a lower extremity MSKI. CONCLUSION: Output scores from this commercially available force plate system did not identify Air Force Special Warfare trainees at elevated risk of experiencing an MSKI.

Association Between Markerless Motion Capture Screenings and Musculoskeletal Injury Risk for Military Trainees: A Large Cohort and Reliability Study.

BACKGROUND: Markerless motion capture (MMC) systems used to screen for musculoskeletal injury (MSKI) risk have become popular in military and collegiate athletic settings. However, little is known regarding the test-retest reliability or, more importantly, the ability of these systems to accurately identify individuals at risk for MSKI. PURPOSE: To determine the association between scores from a proprietary MMC movement screen test and the likelihood of suffering a subsequent MSKI and establish the test-retest reliability of the MMC system used. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Trainees for the Air Force Special Warfare program underwent MMC screenings immediately before entering the 8-week training course. MSKI data were extracted from a database for the surveillance period for each trainee. Logistic regression analyses were performed to identify associations between baseline MMC scores and the likelihood of suffering any MSKI or, specifically, a lower extremity MSKI. The test-retest portion of the study collected MMC scores from 10 separate participants performing 4 trials of the standard test procedures. Reliability was assessed using intraclass correlation coefficients by a single rater. RESULTS: Overall, 1570 trainees, of whom 800 (51%) suffered an MSKI, were included in the analysis. MMC scores poorly predicted the likelihood of any or a lower extremity MSKI (odds ratio, 1.01-1.02). Further, receiver operating characteristic curve analyses demonstrated poor sensitivity and specificity for prediction of MSKI with MMC scores (area under the curve = 0.53). Finally, intraclass correlation coefficients from the test-retest analysis of MMC scores ranged from 0.157 to 0.602. CONCLUSION: This MMC system displayed poor to moderate test-retest reliability and did not demonstrate the ability to discriminate between individuals who were and were not likely to suffer an MSKI.

Sexually transmitted infections in U.S. Air Force recruits in basic military training.

This study reports the counts, prevalence, and trends of five common sexually transmitted infections (STIs) among U.S. Air Force recruits during 2012-2014. Chlamydia and genital herpes simplex virus (HSV) were the most commonly identified STIs in females, with a prevalence of 4,841.2 and 432.3 per 100,000, respectively. Genital HSV was the most commonly identified STI in males at 133.4 per 100,000. There were 13 cases of chlamydia and gonorrhea co-infection among females and none among males. STI prevalence was lower than in a similarly aged U.S. civilian population.

Description and Rate of Musculoskeletal Injuries in Air Force Basic Military Trainees, 2012-2014.

CONTEXT: Musculoskeletal injuries are common in military trainees and have significant medical and operational effects. OBJECTIVE: To provide current musculoskeletal injury epidemiology data for US Air Force basic military trainees. DESIGN: Descriptive epidemiologic study with cross-sectional features. SETTING: US Air Force Basic Military Training, Joint Base San Antonio-Lackland, Texas. PATIENTS OR OTHER PARTICIPANTS: All recruits who entered training between July 1, 2012, and June 30, 2014. MAIN OUTCOME MEASURE(S): Incidence density rate of all musculoskeletal injuries (stratified by body region and type) and factors and costs associated with injuries. RESULTS: Of the 67 525 trainees, 12.5% sustained 1 or more musculoskeletal injuries. The overall incidence density rate was 18.3 injuries per 1000 person-weeks (15.1 for men and 29.4 for women). The most common diagnosis (n = 2984) was Pain in joint, lower leg, as described in the International Classification of Diseases, Ninth Revision, Clinical Modification, code 719.46. Injuries were more common among those with lower levels of baseline aerobic and muscular fitness. Injured trainees were 3.01 times (95% confidence interval = 2.85, 3.18) as likely to be discharged, and injured trainees who did graduate were 2.88 times (95% confidence interval = 2.72, 3.04) as likely to graduate late. During the surveillance period, injuries resulted in more than $43.7 million in medical ($8.7 million) and nonmedical ($35 million) costs. CONCLUSIONS: Musculoskeletal injuries, predominantly of the lower extremities, have significant fiscal and operational effects on Air Force Basic Military Training. Further research into prevention and early rehabilitation of these injuries in military trainees is warranted.

Measles, Mumps, and Rubella Titers in Air Force Recruits: Below Herd Immunity Thresholds?

INTRODUCTION: Preventable diseases like measles and mumps are occurring with increasing frequency in the U.S. despite the availability of an effective vaccine. Given concern that an outbreak may occur among military recruits, we compared serologic evidence of immunity to measles, mumps, and rubella among military recruits with known herd immunity thresholds and determined whether the current Department of Defense policy of presuming mumps immunity based on measles and rubella titers is reliable. METHODS: Serum antibody levels for measles, mumps, and rubella were obtained from all new recruits upon arrival at Joint Base San Antonio-Lackland, Texas, from 25 April 2013 through 24 April 2014. Seroprevalence of each disease was assessed by age and sex, and concordance between mumps titers and measles and rubella titers was calculated. Data analysis was performed in 2014-2015. RESULTS: Among 32,502 recruits, seroprevalences for measles, mumps, and rubella antibodies were 81.6%, 80.3%, and 82.1%, respectively. Of the 22,878 recruits seropositive for both measles and rubella antibodies, 87.7% were also seropositive for mumps. CONCLUSIONS: Seroprevalences for measles, mumps, and rubella antibodies among a large cohort of recruits entering U.S. Air Force basic training were generally lower than levels required to maintain herd immunity. In order to reduce the incidence of mumps infections, the Department of Defense should consider obtaining antibody titers for measles, mumps, and rubella and vaccinating all individuals susceptible to one or more of the viruses.

The effects of prenatal vitamin supplementation on operationally significant health outcomes in female air force trainees.

OBJECTIVES: A prenatal vitamin supplementation program for female basic military trainees at Joint Base San Antonio-Lackland was initiated in June 2012 with the goals of decreasing attrition and improving performance. This project examined whether supplementation influences attrition rates, incidence of stress fractures and iron deficiency anemia, and physical performance. METHODS: This was a cohort-based pilot study with an historical control group. Primary outcome measures included all-cause attrition, medical attrition, stress fractures, and iron deficiency anemia. RESULTS: Incidence rates of all-cause attrition, medical attrition, stress fractures, and anemia were similar in both groups, although the lower medical attrition in the supplementation group approached statistical significance (risk ratio, 0.74; 95% confidence interval, 0.54-1.01). CONCLUSION: Although this study found no statistical benefit, the operationally significant reduction in medical attrition of 26% suggests that providing prenatal vitamin supplementation to female basic trainees in the Air Force may be worthwhile.

Concurrent bilateral femoral neck stress fractures in a military recruit: a case report.

BACKGROUND: Stress fractures are overuse injuries that historically afflict a large number of military recruits, likely because of the sudden increase of high-intensity activity, such as running and marching. CASE: A 23-year-old male U.S. Air Force recruit presented with hip pain during his second week of basic training and was diagnosed with bilateral femoral neck stress fractures, grade 4 on the right and grade 3 on the left. This is the first known case of concurrent bilateral femoral neck stress fractures in a U.S. military recruit reported in the medical literature. CONCLUSION: This report describes a severe case of stress fracture in an individual with no readily identifiable risk factors.

Prevalence and Impact of Anemia on Basic Trainees in the US Air Force.

BACKGROUND: Anemia has been implicated in adverse health outcomes of athletes and military trainees, ranging from overuse injuries to degraded physical and cognitive performance. The purpose of this study was to investigate prevalence of anemia among US Air Force (USAF) basic trainees, to compare physical performance and discharge rates between anemic and non-anemic trainees, and to determine the risks and relative risks of being discharged for anemic versus non-anemic women and men. METHODS: All USAF basic trainees were screened for anemia between July 2013 and January 2014, during an 8-week basic training course at Joint Base San Antonio-Lackland, TX. Age, sex, screening hemoglobin, anthropometric measurements, initial/final physical fitness assessment scores, and discharge data were collected from trainees. Those identified as anemic (hemoglobin <13.5 g/dL for males and <12.0 g/dL for females) received additional labwork, nutritional counseling, and oral iron-replacement, if indicated. Mean percent improvement was calculated for all performance parameters from beginning to end of training. Anemic trainees were compared to non-anemic trainees by t test with Welch modification. Results were stratified by sex and anemia severity with post-hoc Bonferroni correction. RESULTS: Prevalence of anemia was 12.6 % (N = 18,827). Respective prevalence of borderline, moderate, and severe anemia was 12.6, 10.9, and 1.9 % for females and 4.8, 3.8, and 0.3 % for males. Mean 1.5-mile run-time, push-up and sit-up counts improved from beginning to end of training for both anemic and non-anemic trainees (p < 0.001 both). Non-anemic trainees had slightly greater run-time improvements than borderline and moderate anemics (female: 17.7 vs. 15.2, and 15.1 % improvement, p < 0.05 both; male: 14.9 vs. 13.2, and 13.5 % improvement, p < 0.05 both). One-way ANOVA demonstrated statistically significant differences between initial and final fitness data for all measures and both genders (p < 0.001) with the exception of final sit-up counts for male trainees (p = 0.082). Discharge rate for anemic trainees was 9.0 % (20 % for severely anemic trainees) as compared to 5.7 % for non-anemics. CONCLUSIONS: Anemia was prevalent among USAF basic trainees. Identification and treatment of anemia may optimize physical performance and decrease the rate of medical discharge.

Staphylococcus aureus and other skin and soft tissue infections among basic military trainees, Lackland Air Force Base, Texas, 2008-2012.

Military training environments have been identified as high-risk settings for acquisition of skin and soft tissue infections (SSTIs), including those caused by methicillin-resistant Staphylococcus aureus (MRSA). Among the 148,355 basic military trainees at Lackland Air Force Base, Texas, between 1 October 2008 and 30 September 2012, there were 289 SSTIs, including 48 cases of culture-confirmed MRSA and 48 cases of possible MRSA-defined as SSTIs treated with both incision and drainage and MRSA drug coverage (i.e., trimethoprim-sulfamethoxazole, clindamycin, a tetracycline, or linezolid). The period prevalence rates of all SSTIs and MRSA SSTIs increased annually since fiscal year 2010. Of the 87 SSTIs cultured during the surveillance period, 74 were positive: MRSA (n=48); methicillin-sensitive Staphylococcus aureus (n=24); Haemophilus parainfluenzae (n=1); and viridans Streptococcus (n=1). Among MRSA positive cultures, three were resistant to clindamycin, one to tetracycline, and one to both clindamycin and tetracycline; none was resistant to trimethoprim-sulfamethoxazole. An algorithmic clinical approach and heightened public health measures may reduce rates of future SSTIs among basic trainees at Lackland Air Force Base.