Development and evaluation of a universal contoured cushion

Comparison of teaching methods to learn a tilt and balance wheelchair skill

Often service professionals working with individuals who use wheelchairs find themselves inadequately prepared to give hands-on or verbal assistance in wheelchair maneuverability skills. The purpose of this study was to examine the effectiveness of two methods of teaching a tilt and balance wheelchair skill, evaluated by using an obstacle course. Subjects were 30 volunteers, having no past wheelchair experience. The Instruction group viewed an instructional video followed by structured wheelchair practice. The Instruction plus Biomechanics group experienced these same interventions and received a biomechanical explanation of the wheelchair skill. The Control group received no instruction but did receive additional practice time in a wheelchair. It was hypothesized that the first two groups would improve their maneuverability in the wheelchair over the Control group. A 2-way analysis of variance, with main effects for groups followed by a Tukey post hoc test, indicated that the two instruction groups had significantly better times on the obstacle course, demonstrating better maneuverability skills than the Control group. The repeated-measures portion of the analysis of variance showed the main effect for improving time from the pretest to posttest significant for all groups with the instruction groups improving times by 30 sec. over that of the Control group. The retention test was not significantly different from the posttest, and there were no significant interactions. Results indicated a need for wheelchair users to be taught maneuverability skills systematically.

A randomized control trial to evaluate pressure-reducing seat cushions for elderly wheelchair users

OBJECTIVE

To determine if the use of pressure-reducing wheelchair cushions for elderly nursing home resident wheelchair users who are at high risk for developing sitting-acquired pressure ulcers would result in a lower incidence rate of pressure ulcers, a greater number of days until ulceration, and lower peak interface pressures compared with the use of convoluted foam cushions over a 12-month period. To determine the feasibility of conducting a subsequent full-scale definitive trial to evaluate the use of pressure-reducing seat cushions for elderly nursing home resident wheelchair users.

DESIGN

Randomized control trial

SETTING

2200-bed skilled nursing facilities (1 suburban and 1 urban academic medical center)

PATIENTS

32 male and female at-risk nursing home residents who were wheelchair users > or = 65 years of age. Participants had Braden Scale scores < or = 18, Braden Activity and Mobilitysubscale scores < or = 5, no sitting surface pressure ulcers, and a daily wheelchair sitting tolerance of more than 6 hours. All met criteria for using the ETAC Twin wheelchair.

INTERVENTIONS

Seating evaluation with pressure-mapping and subsequent seating prescription. Subjects were assigned to either a foam (n=17) or pressure-reducing cushion (n=15) group and weekly assessments of skin and pressure ulcer risk were made.

MAIN OUTCOME MEASURES

Incidence of pressure ulcers, days to ulceration, and peak interface pressure.

MAIN RESULTS

At a 95% confidence interval, a 2-tailed analysis showed no differences between the FOAM and pressure-reducing cushion groups for pressure ulcer incidence, total days to pressure ulcer, or initial peak interface pressure. Pressure-reducing cushions were more effective in preventing sitting-acquired (ischial) pressure ulcers (P<.005). Higher interface pressures were associated with a higher incidence of pressure ulcers (P<.001).

CONCLUSIONS

A definitive randomized control multicenter cushion trial is feasible with a sample size of 50 to 100 per study group. In the definitive trial, the definition of sitting-acquired pressure ulcers should be limited to lesions occurring over the ischial tuberosities.

Determination of generic body-seat interface shapes by cluster analysis

The purpose of this study was to determine typical or generic shape patterns of the buttock-seat interface for elderly wheelchair users. The group of subjects was composed of 30 elderly people (aged 65 or older) and the shapes of the body-seat interface were measured by the electronic shape sensor (ESS). By analyzing the dissimilarity in geometrical shape descriptors or parameters, four distinct generic shapes were identified by means of the cluster analysis method. The results suggest that the generic shapes were mainly characterized by the lateral symmetry of the shapes. The determination of elderly people's seat interface shapes into distinct clusters may lead to a more comprehensive understanding of the seat support interface and more effective seat cushion designs.