The hammock effect of wheelchair cushion covers: persistent redness over the ischial tuberosities in a patient with spinal cord injury - a case report.

We report a case of a 28-year-old man with a complete C5 level spinal cord injury who developed persistent redness over his ischial tuberosities due to his wheelchair cushion cover's hammock effect. He had purchased wheelchairs and cushions in 2004 and 2008. Persistent redness occurred over his ischial tuberosities when using the second cushion purchased in 2008. Pressure mapping did not detect any differences in pressure over the ischial tuberosities with different cushions. When comparing cushions without their covers, we noticed that the first cushion had a greater air volume than the second cushion. We exchanged the cushion covers to evaluate the hammock effect due to different covers. We found that the redness occurred at any time the second cushion cover was used. After the patient's family changed the top of the second cushion cover to a more elastic material, the redness resolved. As we were unable to detect the influence of the hammock effect using pressure mapping, it would be useful to develop an alternative method to evaluate this phenomenon. It would also be valuable to find a readily available solution for other patients experiencing this problem.