Orthotic-Style Off-Loading Wheelchair Seat Cushion Reduces Interface Pressure Under Ischial Tuberosities and Sacrococcygeal Regions

A systematic review of the effectiveness of pressure relieving cushions in reducing pressure injury

This systematic review seeks to gather and analyze the evidence on wheelchair pressure relieving cushions, and report on the optimal materials and designs for reducing pressure injury risk. The following research question guides this study: Which wheelchair cushions best reduce pressure injury risk? PIs continue to impact the health and function of wheelchairs users with significant mobility impairments. Pressure relieving cushions are typically prescribed to provide pressure relief in the pre-wound, wound, and post-wound phases. Presently, no published reviews analyze all of the commonly available cushion materials. Most comparison studies typically address a specific population such as spinal cord injury, or only a few styles of cushion design/materials. Results suggest air-cell cushions provide optimal pressure relief and shear reduction. Furthermore, small sample single cohort studies suggest off-loading cushions provide superior pressure relief beyond that of air-celled cushions but require additional research for greater generalizability.

OFF-LOADING PRESSURE RELIEF WITH FOAM CUT OUT CUSHIONS: EXPERIENCES FROM RANCHO LOS AMIGOS NATIONAL REHABILITATION CENTER

This paper explores the efficacy of the cushion fitting technique using foam cut out cushions for off-loading bony prominences in the sitting position, with a particular focus on reducing the high risk of developing pressure injuries among aging wheelchair users. This technique, historically employed at Rancho Los Amigos National Rehabilitation Center, has shown promising results in reducing pressure injuries for patients with spinal cord injuries. However, its widespread adoption remains limited. This manuscript aims to raise awareness about foam cut out cushions, its historical context, and its contemporary relevance by presenting customized solutions for individual patients with specific deformities. Key clinical points are highlighted, emphasizing the importance of skilled clinicians in the fitting process and the need to consider foam cut out cushions alongside other preventive measures. Case examples illustrate successful outcomes, demonstrating improved pelvic stability, posture, and off-loading of bony prominences. By promoting foam cut out cushions as a valuable cushioning option, this manuscript equips clinicians with knowledge to utilize this technique effectively.

Upright vs. supine shape-capturing comparison for custom-contoured cushions

AIMS

This study aims to explore best practices of shape capturing methods for creating custom-contoured wheelchair cushions for the purpose of reducing pressure injury risk.

MATERIALS AND METHODS

Pressure redistribution qualities were measured by peak pressure index (PPI) and compared between custom-contoured seating systems molded in supine vs. upright shape-capturing positions. Subjects consisted of 14 able-bodied participants in a within-subjects comparison.

RESULTS

A Wilcoxon signed-rank test and paired t-test were calculated to compare the mean differences of the PPI between shape-capturing positions. Supine shape-capturing resulted in a statistically significant lower PPI compared to upright (z = 2.040, p < . 05) (t = -2.28, p < .05).

CONCLUSION

Shape-capturing in the supine position provided greater pressure distribution as opposed to an upright position. Creating custom-contoured cushions molded in a supine position can reduce the risk of pressure injury to the patient.

Procedure to categorize wheelchair cushion performance using compliant buttock models

Purpose: Wheelchair cushion prescription often seeks to address tissue integrity in addition to other clinical indicators. Because hundreds of wheelchair cushion models are available, a benefit would result if cushions were classified in a more valid manner to help guide selection by clinicians and users. The objective of this research was to develop an approach to evaluate and classify wheelchair cushion performance with respect to pressure redistribution.

Materials and methods: Two anatomically-based buttock models were designed consisting of an elastomeric shell that models overall buttock form and a rigid substructure that abstracts load-bearing aspects of the skeleton. Model shapes were based upon elliptical and trigonometric equations, respectively. Two performance parameters were defined, pressure magnitude and pressure redistribution. The pressure magnitude parameter compared internal pressure values of the test cushion to a flat foam reference material, resulting in three classifications, superior, comparable, and inferior. Surface sensors were used to distinguish cushions with high, moderate or low pressure redistribution performance. Ten wheelchair cushions were evaluated by both models using two loads that represent a range of body weights expected for 41–43 cm wide cushions.

Results and Conclusion: A classification matrix is proposed using both models and performance parameters. Two cushions met criteria for the highest level of performance, and one cushion was deemed to have inadequate performance for therapeutic value. The proposed method has a sensitivity to discern differences, compatibility with different sized cushions, and a versatility in classification. As such, it stands as an improvement over existing classification approaches.

Interface pressure reduction effects of wheelchair cushions in individuals with spinal cord injury: a rapid review

OBJECTIVE

Wheelchair cushion is routinely used to manage the sitting acquired pressure for an individual with spinal cord injury, but which kind of wheelchair cushion performs better in terms of interface pressure management is unclear. This review aims to compare different kinds of wheelchair cushions on their effect of interface pressure reduction in individuals with spinal cord injury.

METHODS AND RESULTS

The databases of MEDLINE, CINAHL, EMBASE and Web of Science were searched. Totally 10 studies were included in this review. Seven of the included studies indicated that air cushions were superior to gel cushions in interface pressure reduction. Three of the included studies reported that gel cushions were superior to polyurethane foam cushions in interface pressure reduction. The variables of measurement duration, measurement focus, measurement devices, cushion covering, sample variations and body positioning of patients may confound the comparison of interface pressure reduction effect of different wheelchair cushions among studies.

CONCLUSIONS

Air cushion was reported more consistently effective in interface pressure reduction than gel and foam cushions. While the variable parameters (measurement duration, focus, devices) and individual conditions (BMI, body positioning) may interfere the comparison among studies. Researches disseminating consistent parameters and clinical prescriptions with individualized evaluation are suggested for the establishment of an evidence-based practice in clinic.Implications for rehabilitationWheelchair cushion is routinely used for an individual post spinal cord injury to manage the sitting acquired pressure.Which kind of wheelchair cushion performs better in terms of interface pressure management is unclear.Air cushion is found more consistently effective in interface pressure reduction than gel cushion and foam cushion.Individualized evaluation of the interface pressure is suggested for the prescription of wheelchair cushion in clinic.

CLINICAL EFFECTIVENESS OF 3D-MODELING-BASED CUSTOMIZED OFF-LOADING PRESSURE-RELIEF CUSHIONS FOR SPINAL CORD INJURY

This study aimed to investigate the effectiveness of a 3D-modeling-based customized off-loading cushion to prevent pressure ulcers in people with spinal cord injury (SCI) using wheelchairs. The study included five people with SCI who use the traditionally manufactured customized off-loading cushions. As part of the test, each subject sat on three types of pressure-relief cushions, and the pressure between the seating surface and cushion was measured for 60[Formula: see text]min. The average measured pressure values were compared, and the change in pressure with time was analyzed to verify the clinical effect. The results showed that the CAD/CAM-based customized off-loading cushion exhibited a better decrease in pressure and pressure distribution effect on the ischial tuberosity and coccyx than the adjustable air cushion but did not differ much from the traditionally manufactured customized off-loading cushion. The clinical and economic effectiveness of the customized off-loading cushion based on the computer-aided design and manufacturing (CAD/CAM) technology was analyzed and tested on people with SCI. An occupational therapist evaluating the client followed by designing the customized off-loading strategy has no difference in terms of clinical effect compared to the traditional manufacturing method. However, time, effort, and cost should be considered when choosing an intervention strategy.

Evaluation of interface pressure and temperature management in five wheelchair seat cushions and their effects on user satisfaction

BACKGROUND

Factors such as the manufacturing materials, shape or even the mechanical and thermal response of sitting Pressure Redistribution Support Surfaces (PRSS) can be potential contributors to pressure ulcers. However, few studies have compared a number of characteristics of the most frequently used devices.

OBJECTIVE

To compare three potential contributors to pressure ulcers in five commercial PRSS: pressure redistribution, temperature and perceived comfort.

METHOD

Study with a cross-over randomized design in healthy volunteer participants. Data was collected in a temperature and relative humidity controlled environment. To assess thermal response, the temperature (Flir-E60) of the region of interest was captured before and after use of each PRSS for further analysis. The region of interest was the gluteal zone. To assess the pressure redistribution a pressure mat (XSensor®) was used between the 5 cushion and each study participant using a standardized method. Finally, a subjective perception questionnaire recorded comfort, adaptability and thermal sensation parameters. Data analysis levels of significance were set at 0.05.

RESULTS

A total of 22 participants completed the assessments. There were no statistically significant differences in baseline temperatures between PRSS (>0.05). Pressure redistribution analysis showed significant differences between all PRSS in all variables evaluated except in the maximum and peak pressure index al sacrum. The subjective assessment suggested no major user-perceived differences between PRSS.

CONCLUSION

Seat cushions made of open cell polyurethane foam blocks of variable hardness and the horseshoe cushion (also open cell polyurethane foam) seem to provide a more effective pressure relief characteristic than those injected with polyurethane foam and gel in most of the studied pressure variables. However, the cushions provide similar thermal response and perceived comfort.

A STUDY OF PRESSURE DISTRIBUTION EFFECT AND USER SATISFACTION OF A CUSTOMIZED OFF-LOADING CUSHION BASED ON 3D MODELING: A COMPARISON WITH CONVENTIONAL AIR CUSHIONS

The study was to compare an off-loading cushion, designed for individuals with spinal cord injury, with air cushion to analyze the effect of pressure on skin injury and user satisfaction. The off-loading cushion can reduce the incidence of pressure ulcers by minimizing the pressure of the ischial tuberosity and coccyx. Because anatomical structures of each participant are different, 3D scanning is used in the customized manufacturing of the cushions. In the 3D modeling, the product is designed so that the ischial tuberosity and coccyx have minimal contact with the cushion’s surface area. The X-sensor was used to confirm the pressure dispersion effect. As a result, maximum pressure of the ischial tuberosity and the coccyx were measured and observed to be lower than that of the air cushion. User satisfaction was compared between two cushions using the QUEST 2.0. The off-loading cushion has slightly higher service and product satisfaction than the air cushion. Based on these findings, this study suggests that off-loading cushions reduce the occurrence of pressure injury compared to air cushions.

A STUDY OF PRESSURE DISTRIBUTION EFFECT AND USER SATISFACTION OF A CUSTOMIZED OFF-LOADING CUSHION BASED ON 3D MODELING: A COMPARISON WITH CONVENTIONAL AIR CUSHIONS

The study was to compare an off-loading cushion, designed for individuals with spinal cord injury, with air cushion to analyze the effect of pressure on skin injury and user satisfaction. The off-loading cushion can reduce the incidence of pressure ulcers by minimizing the pressure of the ischial tuberosity and coccyx. Because anatomical structures of each participant are different, 3D scanning is used in the customized manufacturing of the cushions. In the 3D modeling, the product is designed so that the ischial tuberosity and coccyx have minimal contact with the cushion’s surface area. The X-sensor was used to confirm the pressure dispersion effect. As a result, maximum pressure of the ischial tuberosity and the coccyx were measured and observed to be lower than that of the air cushion. User satisfaction was compared between two cushions using the QUEST 2.0. The off-loading cushion has slightly higher service and product satisfaction than the air cushion. Based on these findings, this study suggests that off-loading cushions reduce the occurrence of pressure injury compared to air cushions.