PulStar differential compliance spinal instrument: a randomized interexaminer and intraexaminer reliability study

To provide an entry-level, new technology reliability assessment of the PulStar computer-assisted, differential compliance spinal instrument.

Eighteen college students (9 male and 9 female) were recruited by announcements and personal contacts.

Following approval of the consent process by the Institutional Review Board of Mississippi State University, a PulStar Function Recording and Analysis System (PulStarFRAS) device was evaluated for clinical reliability. Two examiners, blinded from data collection, used the instrument on individual subjects in random order (lying prone with their backs exposed) to administer light impulses (approximately equal to .9 J which produced a 3- to 4-lb force) at each segmental level throughout the cervical, dorsal, and lumbar spine using probe tips spaced 3 cm apart, straddling the spinous processes, while a computer recorded the findings (resistance on a scale of 0 to 25.5 lb force). Data were analyzed by Exploratory Data Analysis (EDA) with analysis of variance (ANOVA) testing and by use of the intraclass correlation coefficient (ICC). In addition, a mean test (ANOVA) was conducted to determine if a trend in variation occurred as a result of repeated light thrusts to the spine, independent of variance explained by different examiners.

Using EDA analysis and ANOVA, intraexaminer reliability for the 2 practitioners was very high but not perfect. This was confirmed by ICC statistics demonstrating good to excellent reliability for both practitioners (0.89 for the experienced practitioner, 0.78 for the newly trained practitioner). Interexaminer reliability of PulStar was similarly very high but not perfect based on EDA/ANOVA analysis and good to excellent (ICC = 0.87).

The PulStar mechanical adjusting device set to analysis mode appears to have good to excellent reliability when used by either an experienced or a novice (but trained) examiner. In addition, as a measure for resistance to a light thrust or spinal compliance, reliability was similarly good to excellent between the 2 doctors using the PulStar instrument.