The role of strength and power during performance of high intensity military tasks under heavy load carriage.

OBJECTIVE: Previous research has investigated the physiological determinants of heavy load carriage while performing medium to long distance road marching, yet research examining the physiological underpinnings of high-intensity battlefield tasks is limited. This study sought to examine the role of strength and power during high-intensity combat tasks under heavy load carriage. METHODS: Eighteen recreationally trained men (mean±SD: age, 21±2 years; height, 172±6 cm; weight, 80±13 kg) participated in this study and performed an anaerobic combat course under 2 randomized experimental conditions; unloaded and loaded. Subjects performed 3 trials under each condition on separate days, with a 5-minute rest between each trial. In the unloaded trial, subjects wore a uniform with boots weighing approximately 3.2 kg. During the loaded trial, in addition to the uniform and boots, subjects wore Interceptor body armor (6.94 kg-9.10 kg) and a MOLLE rucksack weighing 30 kg. The course consisted of 3 consecutive tasks, which began from the prone position, led into a 30 m sprint, followed by a 27 m zigzag run, and ended with a 10 m casualty drag weighing approximately 79.4 kg. RESULTS: Pearson correlations showed significant (P≤.05) strong correlations between lower body strength (r=-0.63, -0.62), lower body power (r=-0.67, -0.67) and upper body strength (r=-0.60, -0.62) and overall performance times in the unloaded and loaded condition, respectively. CONCLUSION: Strength and power are strongly related to high-intensity military tasks with and without heavy load carriage.

Investigation of the Impact of Sports, Exercise, and Recreation Participation on Psychosocial Outcomes in a Population of Veterans with Disabilities: A Cross-sectional Study.

OBJECTIVE: The aim of this study was to investigate possible effects that participation in sports, exercise, and recreation may have on self-esteem and quality-of-life in service members/veterans with disabilities. DESIGN: Two hundred twenty service members/veterans with disabilities who were participants in one of three annual adaptive sporting events took part in this cross-sectional study. Variables of interest were years of sport, exercise, and recreation participation since the onset of disability as well as the type of activity they engaged in. Main outcome measures were self-esteem and quality-of-life. RESULTS: A positive relationship was found between participant quality-of-life and the number of years spent participating in sports, exercise, and recreation since the onset of their disability. A significant difference was found between pre-event and postevent self-esteem scores. A significant difference was also found in self-esteem scores between the levels of years of participation in sports, exercise, and recreation when averaged across activity type. Finally, there were significant differences found on self-esteem scores between the levels of type of activity averaged across years of participation. CONCLUSIONS: Our results indicate that participation in sports, exercise, and recreation has a positive influence on self-esteem and quality-of-life in individuals with disabilities.

Factors related to high-level mobility in male servicemembers with traumatic lower-limb loss.

The purpose of this study was to examine the possible relationship between factors modifiable by rehabilitation interventions (rehabilitation factors), other factors related to lower-limb loss (other factors), and high-level mobility as measured by the Comprehensive High-Level Activity Mobility Predictor (CHAMP) in servicemembers (SMs) with traumatic lower-limb loss. One-hundred eighteen male SMs with either unilateral transtibial amputation (TTA), unilateral transfemoral amputation (TFA), or bilateral lower-limb amputation (BLLA) participated. Stepwise regression analysis was used to develop separate regression models of factors predicting CHAMP score. Regression models containing both rehabilitation factors and other factors explained 81% (TTA), 36% (TFA), and 91% (BLLA) of the variance in CHAMP score. Rehabilitation factors such as lower-limb strength and dynamic balance were found to be significantly related to CHAMP score and can be enhanced with the appropriate intervention. Further, the findings support the importance of salvaging the knee joint and its effect on high-level mobility capabilities. Lastly, the J-shaped energy storage and return feet were found to improve high-level mobility for SMs with TTA. These results could help guide rehabilitation and aid in developing appropriate interventions to assist in maximizing high-level mobility capabilities for SMs with traumatic lower-limb loss.

Comparison of prosthetic feet prescribed to active individuals using ISO standards.

BACKGROUND: Little research has been done on the robustness of prosthetic feet prescribed to military personnel, and manufacturers are not required to test their products prior to sale. This is problematic because the prosthetic feet used by active individuals are subjected to loading conditions not seen in normal gait. OBJECTIVES: To evaluate whether commercially available heavy-duty prosthetic feet intended for use by military personnel meet ISO 10328 standards. STUDY DESIGN: Bench testing of heavy-duty prosthetic feet using ISO 10328 standards. METHODS: Prosthetic feet from three different manufacturers were tested according to ISO 10328 standards, using a testing frame fitted with axial load and displacement transducers. Pass/fail information was recorded as well as the stiffness and creep of each foot before and after cyclic testing. RESULTS: All feet passed the ISO 10328 standards at the highest loading level, and some significant differences were found within a given model of prosthesis when comparing stiffness and creep before and after cyclic testing. CONCLUSIONS: This study demonstrated that manufacturers of heavy-duty prosthetic feet adhere to the voluntary ISO 10328 standards. However, these standards may be insufficient because the tests simulate only idealized gait. Further development of the standards may be necessary to reproduce the circumstances that occur during extreme usage to ensure that prosthetic feet do not fail.

Wheeled mobility: factors influencing mobility and assistive technology in veterans and servicemembers with major traumatic limb loss from Vietnam war and OIF/OEF conflicts.

Returning wounded veterans and servicemembers to their highest level of function following traumatic injury is a priority of the Departments of Defense and Veterans Affairs. We surveyed 245 veterans from the Vietnam war and 226 servicemembers and veterans from Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) conflicts with at least one major traumatic lower-limb loss to determine their use of mobility assistive technology (AT) and patterns of limb abandonment. Prosthetic device use without wheelchair use is found in 50.5% of Vietnam and 42.8% of OIF/OEF groups. Prostheses and supplementary wheelchairs are used by Vietnam (32%) and OIF/OEF (53%) groups (p < 0.01). Exclusive wheelchair use is more frequent in the Vietnam group (18%) than in the OIF/OEF group (4.0%, p < 0.01). In Vietnam participants, multivariate analysis found that multiple-limb loss (adjusted odds ratio [AOR] = 14.5; 95% confidence interval [CI] 5.5-38.5), bilateral lower-limb loss (AOR = 12.7; 95% CI 6.2-26.1), and number of comorbidities (AOR = 1.3; 95% CI 1.2-1.5) are associated with increased likelihood of wheelchair use. In OIF/OEF participants, bilateral lower-limb loss (AOR = 29.8; 95% CI 11.0-80.7), multiple-limb loss (AOR = 16.3; 95% CI 3.1-85.3), cumulative trauma disorder (AOR = 2.4; 95% CI 1.2-4.9), and number of combat injuries (AOR = 1.4; 95% CI 1.2-1.7) are associated with wheelchair use. Combined use of different types of mobility ATs promotes improved rehabilitation and ability to function.

Advances in lower-limb prosthetic technology.

The boundaries once faced by individuals with amputations are quickly being overcome through biotechnology. Although there are currently no prosthetics capable of replicating anatomic function, there have been radical advancements in prosthetic technology, medical science, and rehabilitation in the past 30 years, vastly improving functional mobility and quality of life for individuals with lower-limb amputations. What once seemed impossible is rapidly becoming reality. The future seems limitless, and the replication of anatomic function now seems possible.