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To combat the devastating effects of improvised explosive devices (IEDs), body armor that provides extended coverage has been developed. However, this extended coverage increases the armor's weight and may restrict movement. Throughout this case study, a novel technique to assess several armor systems was investigated. Four soldiers performed shoulder and trunk movements while wearing each of the six different armor inserts. Electromyography (EMG) was used to quantify muscular activity and inertial motion sensors were used to determine joint range of motion (ROM). Outcome measures included maximum ROM, integrated EMG, and the soldiers' subjective rankings. For the shoulder tasks, objective ROM and EMG measures were related to each other as well as to subjective rankings and armor material properties. Conversely, little agreement was found between measures for the trunk tasks. Results of this preliminary investigation indicate that combining shoulder ROM and EMG measures has the potential to provide an objective assessment of body armor systems.

Background and Purpose: This cross-sectional study evaluated the relative contributions of psychosocial and mechanical variables to physical performance measures in people with knee osteoarthritis (OA)., Subjects: Fifty-four subjects (age, in years: mean=68.3, SD=8.7, range=50-87) with radiographically confirmed knee OA were included in this study., Methods: Physical performance measures included the Six-Minute Walk Test (SMW), the Timed "Up & Go" Test (TUG), and a stair-climbing task (STR). Responses to psychosocial questionnaires that reflect depression, anxiety, and self-efficacy (a person's confidence in his or her ability to complete a task) were collected. Mechanical variables measured included body mass index and knee strength (force-generating capacity of muscle). Stepwise linear regressions were performed with the SMW, TUG, and STR as separate dependent variables., Results: Functional self-efficacy explained the greatest amount of variance in all performance measures, contributing 45% or more. Knee strength and body weight also explained some variance in performance measures. Anxiety and depression did not explain any variance in performance., Discussion and Conclusion: Physical therapists evaluating the significance of the SMW, TUG, and STR scores in subjects with knee OA should note that a large part of each score reflects self-efficacy, or confidence, for physical tasks, with some contributions from knee strength and body weight.

The mechanical energy costs of walking were studied in 10 cerebral palsied children with hemiplegia to determine whether their values were substantially different from normal and, if so, to discover the movements that were responsible. A two-dimensional, sagittal-plane cinematographic analysis of the subjects' normal walking was undertaken. This technique provided continuous information about the mechanical energy costs of the whole body and each of its parts, the energy types involved, and the amounts of energy conserved. In most cases, the energy costs were above normal and were attributable to poor patterns of exchange between the potential and kinetic energy types of the head, arms, and trunk segment; to very low levels of kinetic energy that precluded exchange; or to both. We concluded that attention should be directed to restoring the sinusoidal pattern of motion and to the fluctuating speeds during each gait cycle when energy costs are a therapeutic consideration.