Comparison of perceived pain with different immobilization techniques.
To compare the locations and severities of pain generated by a hard wooden spine board vs a soft vacuum mattress splint on immobilized volunteers. This was a prospective randomized crossover study conducted in an emergency medical services (EMS) classroom within a university teaching hospital. Participants were 18 healthy volunteers with no history of acute or chronic back pain, pregnancy, or recent analgesic use. The subjects were placed in one of three immobilization boards (hard spine board and two different vacuum splint models, identified as red and blue) for 60 minutes. At 0, 30, and 60 minutes the subjects rated their pain at multiple locations on their body using a visual analog scale (VAS). After a two-day washout period, this procedure was repeated on a different board and later a third board until all the subjects had been tested on all three boards. Although many pressure point locations were studied, only three had results that appeared statistically significant: the occiput, lower back, and sacrum. The hard spine board had higher mean pain scores as well as a higher percentage of subjects who reported any pain when compared with the two vacuum mattress splints. Mean scores for the 30- and 60-minute times were: occiput 2.06 and 2.78 for the hard board compared with 0.78 and 0.56 for red and 0.44 and 0.67 for blue; lower back 1.39 and 1.44 for the hard board compared with 0.28 and 1.11 for red and 0.06 and 0.17 for blue; and sacrum 1.56 and 2.06 for the hard board compared with 0.33 and 0.39 for red and 0.89 and 1.06 for blue. The hard-board method of spinal immobilization generates higher self-reported pain scale scores than the two vacuum mattresses.