Background: Collar-related pressure ulcers (CRPU) are a problem in trauma patients with a suspicion of cervical cord injury patients. Indentation marks (IM), skin temperature (Tsk) and comfort could play a role in the development of CRPU. Two comparable cervical collars are the Stifneck® and Philadelphia®. However, the differences between them remain unclear.

Aim: To determine and compare occurrence and severity of IM, Tsk and comfort of the Stifneck® and Philadelphia® in immobilized healthy adults.

Methods: This single-blinded randomized controlled trial compared two groups of immobilized participants in supine position for 20 min.

Results: All participants (n = 60) generated IM in at least one location in the observed area. Total occurrence was higher in the Stifneck®-group (n = 95 versus n = 69; p = .002). Tsk increased significantly with 1.0 °C in the Stifneck®-group and 1.3 °C in the Philadelphia®-group (p = .024). Comfort was rated 3 on a scale of 5 (p = .506).

Conclusion: The occurrence of IM in both groups was high. In comparison to the Stifneck®, fewer and less severe IM were observed from the Philadelphia®. The Tsk increased significantly with both collars; however, no clinical difference in increase of Tsk between them was found. The results emphasize the need for a better design of cervical collars regarding CRPU.