By Tina Beychok
While adjusting instruments for treating spinal disorders have been in use for several decades, their exact biomechanical properties are still not very well understood. Furthermore, it would be useful to be able to evaluate these devices in terms of operator reliability. In other words, will the instrument device respond in the same way for a variety of different levels of operator expertise?
Determining an optimal thrust delivery profile will go a long way toward producing an adjusting device that can deliver within a reliable thrust range, regardless of the experience of the DC using the device.
An article to be published in the December 2014 issue of the Annals of Biomedical Engineering (published first online on Oct. 18, 2014) compared four different instrument adjusting devices to determine the optimal half-sine thrust profile, as well as which device came closest to that thrust profile to provide the greatest possible clinical value when performing spinal adjustments. Researchers performed both bench testing on each of the devices (Activator V-E device, Impulse device, Activator IV/FS device, Activator II device) and clinical testing to determine operator influence on device performance.
Of the three devices, the Activator V-E device came the closest to the ideal thrust profile (94 percent of the time), followed by the Impulse device (84 percent of the time), and then the Activator IV/FS device (74 percent of the time) and the Activator II device (48 percent). The Impulse device was the only tool to exhibit a second peak, while the others deviated from the ideal profile on the return path.
In terms of operator reliability over repeated adjustments, the Activator V-E device showed the greatest reliability despite differences in operator experience. The researchers noted that, according to their findings, a hyperactive spine would receive a lower peak thrust force than a hypoactive spine, regardless of power setting.
Although it is clear that more research still needs to be done to better understand the biomechanical effects of instrument assisted adjusting, being able to determine which device not only comes closest to the optimal thrust profile to provide clinical benefits, but can also perform consistently despite operator skill level can provide more evidence for the safety and efficacy of instrument assisted spinal adjustments.
