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

INTRODUCTION Currently, many servicemembers (SMs) who experience traumatic lower-limb loss (LLL) seek return to Active Duty and return to high-level mobility activities such as sports. Between 2001 and 2009, it is estimated that between 11 to 16 percent of SMs with traumatic LLL at various levels of amputation returned to duty [1-2]. Of SMs with unilateral and multiple LLL, 26 percent from Operation Enduring Freedom and 19 percent from Operation Iraqi Freedom returned to high-level activities such as basketball and skiing [3]. Because many SMs seek return to high-level mobility but not all achieve it, it is important for both the SMs and clinicians involved in their rehabilitation to understand those factors modifiable by rehabilitation interventions (rehabilitation factors) as well as other factors related to LLL that are associated with achieving this goal. Unfortunately, many of these factors are not well understood, in part because, until recently, there was no way to measure high-level mobility at various stages in the rehabilitation process for this population. The Comprehensive High-Level Activity Mobility Predictor (CHAMP) was created to quantify the ability of SMs with limb loss to perform high-level mobility activities. The CHAMP assesses balance, postural stability, coordination, power, speed, and agility in multiple planes of motion and has been demonstrated to be a reliable and valid measure of high-level mobility in SMs with limb loss [4-5]. By using the CHAMP to measure high-level mobility, it may be possible to identify factors that are related to ability to perform high-level mobility activities. This type of information could help guide clinicians in setting rehabilitation goals and developing clinical interventions for SMs with traumatic LLL who want to return to high-level activity. There are a number of factors that potentially can be modified during the rehabilitation intervention that may be related to return to high-level mobility. Rehabilitation factors include muscle strength and power [6-7], range of motion, balance strategies and proprioceptive control [811], and gait pattern [10,12-14]. Other factors include weight [15] and adiposity as reflected by waist circumference, age, time since amputation, number and level of amputations as reflected in the number of remaining intact knee and ankle joints [7,16-18], and condition of the amputated and contralateral lower limb (if applicable), as well as length of the residual limb [19-22]. In addition, prosthetic feet [23-27] and knee units have been shown to affect basic prosthetic mobility and may also affect high-level mobility [12]. The purpose of this study was to examine the possible relationship between rehabilitation factors, other factors, and high-level mobility as measured by the CHAMP in SMs with traumatic LLL. We hypothesized that rehabilitation factors such as strength, balance, and gait components represented by individual test items of the Amputee Mobility Predictor with Prosthesis (AMPPro), and other factors such as weight, waist circumference, age, time since amputation, level of amputation, number of limbs lost, severity of musculoskeletal injury, residual-limb length, prosthetic ankle/foot design, and prosthetic knee device would be related to high-level mobility, as measured by participants' CHAMP scores (Tables 1 and 2). METHODS Study Design This was a cross-sectional, correlative-predictive study. Data were collected at Walter Reed Army Medical Center (WRAMC), Washington, DC; Center for the Intrepid, Brooke Army Medical Center (BAMC), San Antonio, Texas; and Womack Army Medical Center (Womack), Fort Bragg, North Carolina. Participants A convenience sample of 118 Active Duty or retired male SMs between the ages of 18 and 40 yr with traumatic LLL completed the study. Participants who were medically stable with a properly fitting prosthesis and demonstrated a minimal level of function, as determined by ability to walk at least 250 m in the 6-Minute Walk Test, completed the study. …