Skin Protection

Skin and soft tissue protection are often reported as a high priority or goal for individuals who require a specialised cushion. Data from cushion performance metrics can contribute to the clinical reasoning process and cushion selection. Results from immersion testing and pressure redistribution (such as contact area and off-loading) can assist with cushion selection when skin and soft tissue protection are a priority.

Why is immersion the only exception when it comes to pass/fail criteria of performance metrics?

Unlike other performance metrics categorised statistically, immersion follows a pass/fail threshold due to its direct clinical relevance. Clinical Practice Guidelines link immersion to pelvic shape, specifically the distance from the ischial tuberosity to the greater trochanter, which typically ranges from 40 to 45 mm. This measurement informed the design of a standardised bench test, making immersion the only metric with defined thresholds:

Lower priority for immersion: <40 mm
Typical priority for immersion: ≥40 and ≤45 mm
Higher priority for immersion >45 mm

The University of Pittsburgh performed lab-based ISO testing on a total of 50 cushions. Permobil statistically analyzed the data for primary performance metrics into quartiles, or four equal groups. For any one performance metric:

• The 25% cushions with the highest values may be a match for an individual who puts a higher priority on that cushion characteristic.
• The 50% of cushions that are closest to the middle values may be a match for an individual who puts a typical priority on that cushion characteristic
• The 25% of cushions with the lowest values may be a match for an individual who puts a lower priority on that cushion characteristic.

Scientific Report and Understanding Performance Metrics

Interested in learning more?