Temperature provides a clear signal of the time in brace and can be used for long-term data logging using discrete instrumentation, providing a tool to help identify and understand the reasons behind poor compliance.

No abstract

Wheelchair pressure mapping devices used in the prescription of seat cushions and postural supports have been limited in durability, data presentation, and/or clinical efficiency. This project sought to establish the ideal specifications for clinically useful pressure mapping systems, and to use these specifications to influence the design of an innovative wheelchair pressure mapping system (Tekscan "Seat"). Technology, previously developed for measurement of forces of dental occlusion and of the foot during gait, was applied to wheelchair seat mapping. Tests were designed to compare the performance of three pressure mapping systems: the Tekscan system, the FSA system, and the Talley TPM3. Bench tests were done to measure reproducibility, hysteresis, and creep of each of the pressure mapping systems. A contoured loader gauge was developed to test for the influence of hammocking. Tests were also performed using spinal cord-injured subjects to demonstrate the relative performance of the pressure mapping systems in a clinical setting. A focus group session was conducted with seating specialists to review the strengths and weakness of the systems for routine clinical use. The TPM3 was found to be the most accurate, stable, and reproducible but limited in ease of use, speed, and data presentation. FSA was rated well in clinical application and data management but demonstrated a pronounced hysteresis (+/-19%) and creep (4%). The Tekscan system also showed substantial hysteresis (+/-20%) and creep (19%) but was preferred by clinicians for its real-time display capabilities, resolution, and display options. Some trends in system performance on varied support surfaces were identified and can be a valuable guide to interpretation of measurements and prescription decision making in the clinic. Problems identified with the accuracy and stability of the Tekscan and FSA systems may be amenable to resolution with software correction and changes in fabrication. With these improvements all three systems show the potential to be useful clinical tools.

The purpose of this study was to examine the relationship between histomorphometric variables of cancellous bone structure and ultimate compressive strength (UCS) in the second lumbar vertebra (L2) and to determine whether structural variables in the iliac crest are predictive of the same variables and of UCS in L2. At autopsy, 7.5 mm diameter cores were removed from the iliac crest and from L2 of 29 subjects who had died suddenly without bone disease. Cancellous bone volume (BV/TV, %) was significantly lower in L2 than in iliac crest due to lower trabecular number (Tb.N, per mm) and thickness (Tb.Th, microns). There were significant correlations between iliac crest and L2 for BV/TV, Tb.N and trabecular separation (Tb.Sp, microns), but not for Tb.Th. BV/TV was negatively correlated, and Tb.Sp was positively correlated with age at both sites. Tb.Th was not significantly correlated with age in the iliac crest, but a significant negative correlation was observed in L2. The UCS of vertebral cores was negatively correlated with age. BV/TV and Tb.Th in L2 were positively correlated with UCS in L2.(ABSTRACT TRUNCATED AT 250 WORDS)