Reliability of center of pressure measures of postural stability in healthy older adults: effects of postural task difficulty and cognitive load.

Postural instability is a major risk factor of falling in the elderly. It is well documented that postural control may decline while performing a concurrent cognitive task and this effect increases with age. Despite the extensive use of dual tasking in balance assessment protocols, a lack of sufficient reliability information is evident. This study determines the reliability of the postural stability measures in older adults, assessed under single and dual-task conditions and different levels of postural difficulty. Sixteen older adults completed quiet stance postural measurements at three levels of difficulty (rigid surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed), with or without performing a concurrent backward counting task, in two sessions 1 week apart. Force plate data was used to calculate center of pressure (COP) parameters including mean velocity, phase plane portrait, area (95% confidence ellipse), standard deviation (SD) of amplitude, and SD of velocity. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), coefficient of variation (CV), and minimal metrically detectable change (MMDC) were calculated for each COP measure in all test conditions. Mean velocity, total phase plane, phase plane in ML direction, and SD of velocity in ML direction were the most reliable COP measures across all test conditions. ICC values were consistently higher in ML direction compared with AP direction. In general, velocity-related COP measures in ML direction showed to be highly reliable. Further research may explore the predictive and evaluative value of these COP parameters.

Factors associated with pressure ulcers in patients with complete or sensory-only preserved spinal cord injury: is there any difference between traumatic and nontraumatic causes?

OBJECT: Pressure ulcers (PUs) are common complications in patients with complete spinal cord injury (SCI) or incomplete SCI in which sensory function is spared. Most studies analyzing associated factors of PU and SCI have been performed in cases of traumatic SCI and in just a few cases of nontraumatic SCI. This study was designed to look specifically at the differences in causative factors of PU in cases of traumatic and nontraumatic SCIs. METHODS: The authors performed a retrospective, cross-sectional study evaluating patients with complete and incomplete SCIs (American Spinal Injury Association Grades A and B) under the coverage of the financial, medicosocial, and rehabilitative support provided by the State Welfare Organization of Iran (SWOI). There were 3791 cases of traumatic SCI (63.2%) and 2110 cases of nontraumatic SCI (35.2%). For 94 patients (1.6%), sufficient data were not available. RESULTS: A PU was detected in 39.2% of all patients with an SCI (71.8% of those with traumatic SCI vs 28.2% of those with nontraumatic SCI). A univariate analysis showed a significant association between occupation, education, and the presence of PU in patients with a traumatic SCI (p < 0.05). This contrasted with nontraumatic SCI in which an association between PU and age was noted (p < 0.05). Using logistic regression, traumatic cause, older age, an interval less than 1 year since the onset of SCI, male sex, and single status were found to significantly increase the risk of PU in all patients with an SCI. However, a higher education level had a preventive effect on PU. CONCLUSIONS: This study revealed some risk factors for PU in the authors' setting. The authors' findings suggest a possible difference between the risk factors for PU in patients with both types of SCI. Further study on the pathoetiology of these differences is paramount in the future.