Seat interface pressures of individuals with paraplegia: influence of dynamic wheelchair locomotion compared with static seated measurements.

OBJECTIVE: To provide a comparison of the seat interface pressures between static seating and dynamic seating during wheelchair locomotion of individuals with paraplegia. DESIGN: Repeated measures multivariate analysis of variance (MANOVA) comparing two conditions: static seat and dynamic seat interface pressures. SETTING: University campus and clinic. PARTICIPANTS: Fifteen participants, each of whom propelled a manual wheelchair for at least 5 hours per week over the previous 6 months and functioned with a spinal cord injury/ disability level of T1 or below. MAIN OUTCOME MEASURES: Peak pressure (PP) and pressure time integral (PTI) as measured by the Novel Pliance System, which consists of a flexible 32 x 32 capacitive sensor mat (each sensor 1.5 cm2) interfaced with a PC, was sampled at 10Hz. The participants were measured in their own wheelchair with a new Jay Active seat cushion. RESULTS: The repeated measures MANOVA showed a difference in the PP and PTI between the static and dynamic measurements (Wilk's = .00, p < .05). Follow-up dependent t tests yielded a difference in PP (t = 5.40, p < 0.025) and no difference in the PTI between static and dynamic conditions (t = 1.45, p > 0.025). The PP during static seating (mean = 16.2 +/- 5.0 kPa [121 +/- 37.5 mmHg]) was less than during dynamic seat interface pressures during wheelchair locomotion (20.03 +/- 6.6 kPa [152.3 +/- 49.5 mmHg]). PP varied by up to 42% during the wheelchair locomotion cycle. The PTI was similar between static (30.1 +/- 9.3 kPa [225.75 +/- 69 mmHg]) and dynamic conditions (36.2 +/- 18.1 kPa [271 +/- 135.7 mmHg]). CONCLUSIONS: The results from this study are consistent with some of the previous work on the nondisabled and a single case study, but with greater external validity because of the nature of the sample chosen and the methodology employed. PPs were greater during dynamic wheelchair locomotion compared with static seating interface pressures, with the peak varying up to 42% during the wheelchair locomotion cycle. The PTI indicates that the cumulative effect of the loading was comparable between conditions. The question that remains is whether this dynamic loading, resulting in a change in PP throughout the cycle, has a significant effect on tissue health.

The use of an automated microsampling system for the characterization of growth hormone pulsatility in newborn babies.

To overcome the difficulties of studying hormone pulsatility in the newborn, we have developed an automated microsampling system that permits the measurement of hormones in small prediluted samples of blood (40 microL) taken at 10-min intervals over 12 h. The system has been validated in adult volunteers, and the error attributable to the dilution was <4%. Using this method in 10 preterm babies, we have been able to describe pulsatile changes in GH and have demonstrated a clear postprandial elevation in GH levels peaking 60 min after a feed. Fourier transform analysis indicated a pulse periodicity of 180 min in babies who were appropriate for gestational age (n = 6), but faster, co-dominant pulse periodicities of 90-100 and 140 min in babies who were small for gestational age (weight and length below the 10th centile) (n = 4). There was no significant difference between mean, peak, and baseline GH levels between the two groups.

Pre-vocational programming in a pediatric skilled care facility.

This article describes a pre-vocational program that was developed in a private residential skilled care pediatric facility, under the guidance of an occupational therapy consultant. This "Special Training Program" was designed to meet the needs of the few higher functioning adolescents and young adults residing within the facility who did not participate in daily community school programs. This paper presents the philosophical issues related to developing a pre-vocational program; the criteria for selecting program participants; the program structure (implementation details, work sample selection, production rate data records, program supervision, participant remuneration, physical set-up and start-up costs); and an evaluation of the benefits and disadvantages of the program following one year of the Special Training Program's initiation date.