Evaluation of Spine Health and Spine Mechanics in Service Members with Traumatic Lower-Extremity Amputation or Injury

Low back pain (LBP) is a clinically important secondary impairment following lowerextremity trauma, with potentially life-long effects for the injured Service Member (SM). To develop targeted interventions for preventing and/or controlling LBP among SMs with lower-extremity trauma, it is critical to first understand more completely the underlying mechanisms linking lower-extremity amputation/injury with LBP onset and recurrence. Alterations in gait and movement subsequent to traumatic lower-extremity amputation/injury are associated with substantial increases and asymmetries in trunk (and pelvic) motions. Therefore, we hypothesize that abnormal spine mechanics (increased loads and decreased stability) accompanying altered spinal alignment and increased trunk/pelvic motion may adversely affect spine health and contribute to LBP risk in SMs with lower-extremity trauma. Accordingly, we will complete a cross-sectional experimental design with four specific aims: 1) Determine current spine health in SMs with traumatic unilateral lower-extremity amputation/injury, 2) Quantify sagittal and coronal lumbar spinal alignment in standing postures in SMs with/without traumatic unilateral lower-extremity amputation/injury, 3) Quantify inter-segmental lumbar motion during gait in SMs with/without traumatic unilateral lower-extremity amputation/injury, and 4) Determine the association between changes in lumbar spinal alignment, segmental motion, and spine mechanics (loading and stability) in SMs with/without traumatic unilateral lower-extremity amputation/injury. By determining the relationships between lower-extremity amputation/injury and altered (and asymmetric) trunk postures and gait on lumbar motion, loading, and stability, we expect to establish a foundation from which to develop and implement targeted interventions for preventing and/or controlling LBP in this population.