Bria Graham

A systematic review of the effects of physical training on load carriage performance.

Knapik, JJ, Harman, EA, Steelman, RA, and Graham, BS. A systematic review of the effects of physical training on load carriage performance. J Strength Cond Res 26(2): 585–597, 2012—Soldiers are often required to carry heavy loads during military operations. This article reports on a systematic literature review examining the influence of physical training on load carriage performance. Several literature databases, reference lists, and other sources were explored to find studies that quantitatively examined the effects of physical training on the time taken for individuals to complete a set distance carrying an external load, with the majority of the load contained in a backpack. Effect sizes (Cohens d statistic) were used in meta-analyses to examine the changes in load carriage performance after various modes of physical training. Effect sizes quantified training-related changes in terms of SD units. Ten original research studies met the review criteria. Meta-analysis indicated that large training effects (≥0.8SD units) were apparent when progressive resistance training was combined with aerobic training and when that training was conducted at least 3 times per week, over at least 4 weeks. When progressive load-carriage exercise was part of the training program, much larger training effects were evident (summary effect size [SES] = 1.7SD units). Field-based training that combined a wide variety of training modes and included progressive load-carriage exercise was also very effective in improving load carriage performance (SES = 1.1SD units). Aerobic training alone or resistance training alone had smaller and more variable effects, depending on the study. This review indicates that combinations of specific modes of physical training can substantially improve load carriage performance.

A prospective investigation of injury incidence and injury risk factors among army recruits in military police training

BackgroundUnited States Army military police (MP) training is a 19-week course designed to introduce new recruits to basic soldiering skills, Army values and lifestyle, and law enforcement skills and knowledge. The present investigation examined injury rates and injury risk factors in MP training.MethodsAt the start of training, 1,838 male and 553 female MP recruits were administered a questionnaire containing items on date of birth, height, weight, tobacco use, prior physical activity, injury history, and menstrual history. Injuries during training were obtained from electronic medical records and the training units provided data on student graduation and attrition.ResultsSuccessfully graduating from the course were 94.3% of the men and 83.7% of the women. Experiencing at least one injury during training were 34.2% of the men and 66.7% of the women (risk ratio (women/men) = 1.95, 95% confidence interval = 1.79-2.13). Recruits were at higher injury risk if they reported that they were older, had smoked in the past, or had performed less frequent exercise or sports prior to MP training. Men were at higher injury risk if they reported a prior injury and women were at higher risk if they reported missing at least six menstrual cycles in the last year or had previously been pregnant.ConclusionThe present investigation was the first to identify injury rates and identify specific factors increasing injury risk during MP training.

A prospective investigation of injury incidence and risk factors among army recruits in combat engineer training

BackgroundUnited States Army combat engineer (ENG) training is an intense 14-week course designed to introduce new recruits to basic soldiering activities, Army values and lifestyle, and engineering skills and knowledge. The present investigation examined injury rates and injury risk factors in ENG training.MethodsAt the start of their training, 1,633 male ENG recruits were administered a questionnaire containing items on date of birth, height, weight, tobacco use, prior physical activity, and injury history. Injuries during training were obtained from electronic medical records and the training units provided data on student graduation and attrition. Risk factors were identified using Cox regression.ResultsNinety-two percent of the recruits successfully graduated from the course and 47% of the recruits experienced one or more injuries during training. Univariate Cox regression demonstrated that recruits were at higher injury risk if they reported that they were older, had a higher or lower body mass index, had smoked in the past, had performed less exercise (aerobic or muscle strength) or sports prior to ENG training, had experienced a previous time-loss lower limb injury (especially if they had not totally recovered from that injury), or had a lower educational level.ConclusionsThe present investigation was the first to identify injury rates and identify specific factors increasing injury risk during ENG training. The identified risk factors provide a basis for recommending future prevention strategies.

Activities Associated With Injuries in Initial Entry Training

Previous studies have not reported activities associated with injuries in initial entry training (IET) because these data were seldom available in medical records and not contained in electronic databases. This investigation obtained activities associated with outpatient encounters in IET recorded by primary medical care providers at Fort Leonard Wood, Missouri. Data were entered into a standard database that included fields for diagnosis and activity associated with the injury. Fifty percent of the new injury encounters (i.e., exclusive of follow-ups) were not associated with a specific event but were reported as having a gradual onset. Other activities included physical training (16%), road marching (15%), confidence/obstacle courses (5%), and barracks activities (3%). Risks per unit of training time were estimated at 13, 62, and 97 injuries per hour for physical training, road marching, and the confidence/obstacle courses, respectively. The most frequently recorded diagnoses were joint pain (27%), strains (15%), blisters (14%), sprains (13%), and tendonitis (12%). The types of injuries and their anatomical locations were similar to those reported in other IET investigations, although blister-related encounters were higher. This investigation identifies activities with the highest risk of injury in IET and those that should be targeted for injury prevention efforts.

Military parachuting injuries, associated events, and injury risk factors

INTRODUCTION The purpose of this investigation was to examine injury incidence, events associated with injury, and injury risk factors during parachuting in an Army airborne infantry unit. METHODS Injury data were obtained by the investigators on the drop zone and confirmed by a physician. Operational data (potential injury risk factors) were obtained from routine reports published by the infantry unit. Weather data were obtained using a Kestrel Model 4500 pocket weather tracker. RESULTS There were a total of 23,031 jumps resulting in 242 injured soldiers for a crude injury incidence of 10.5 per 1000 jumps. Parachute entanglement incidence was 0.5 per 1000 jumps. Where an event associated with the injury could be determined (67% of cases), these included ground impact (75%), static line problems (11%), tree landings (4%), entanglements (4%), and aircraft exits (3%). Univariate analysis showed that higher injury risk was associated with night jumps (versus day jumps), combat loads (versus unloaded jumps), higher wind speeds, higher dry bulb temperatures, higher humidity, C17 Globemaster or C130 Hercules aircrafts (compared to the other aircraft), exits through aircraft side doors (versus tailgates), and entanglements. Multivariate analysis indicated that independent risk factors for injuries included night jumps, combat loads, higher wind speeds, higher dry bulb temperatures, and entanglements. DISCUSSION This investigation provided injury incidence, events associated with injury, and quantitative assessments of injury risk factors and their interactions during military parachuting. An appreciation of these subjects can assist medical and operational planners in further reducing the incidence of injury during airborne operations.

Risk factors for closed-head injuries during military airborne operations.

INTRODUCTION One of the more serious adverse outcomes of military airborne operations is closed-head injuries. This investigation examined risk factors for closed-head injuries in an Army airborne infantry unit. METHODS Closed-head injuries were defined as energy exchanges in which the head contacted the ground or an object and the soldier sought medical care for external trauma, headache, loss of consciousness, or altered mental state. Injury data were obtained by investigators in the drop zone and diagnoses were confirmed by a physician. Operational data on potential injury risk factors were obtained from routine reports published by the infantry unit. Weather data were obtained using a pocket weather tracker. RESULTS There were 96,132 jumps resulting in 310 closed-head injuries for a crude incidence of 3.22/1000 jumps. In 98% of known cases the injury was associated with parachute landings. Multivariate logistic regression revealed that independent risk factors for closed-head injuries included night jumps, combat loads, higher wind speeds, higher temperatures, enlisted rank, and entanglements. CONCLUSIONS This study identifies the current incidence and extrinsic risk factors for closed-head injuries during military airborne operations. Although it is necessary to conduct airborne training under realistic conditions, trainers and commanders should be aware of these risks and plan airborne operations accordingly.