This is hot stuff! What happens when we do instrument assisted spinal manipulation? Read on... Title: Effects of Instrument-Assisted Spinal Manipulation on Lumbar Muscle Spindle Response in an Animal Model. Purpose: To determine how instrument-assisted spinal manipulation affects muscle spindle discharge following thrusts delivered at different magnitudes. Methods: Muscle spindle activity from the L6 spinal root was recorded in 7 anesthetized cats prior to and after spinal manipulative thrusts were delivered to the L7 vertebra using 2 clinical instruments (the PulStar− and Activator V−). Both instruments were used in 3 cats. Typically, 3 thrusts at each of 3 peak magnitudes were delivered with 5 minute intervals between thrusts. Spindle activity was determined in the absence of any contact during 2 secs prior to and immediately following the manipulative thrust. Mean frequency (MF), mean instantaneous frequency (MIF), and time until first action potential (AP) following the thrust were determined. Results: Change from baseline discharge during 2 sec after thrust († n=21, † n=18) Change from baseline discharge during 2 sec after thrust (*n=6, △n=9, ▲n=8) PulStar− Activator V− 5 lbs† 10 lbs† 15lbs† Setting 1* Setting 2△ Setting 3▲ Mean MF (SEM) ✻6.8 (1.2) ✻7.0 (1.4) ✻6.7 (1.7) ✻1.0 (0.2) ✻3.8 (1.9) ✻4.2 (1.8) Mean MIF (SEM) ✻5.2 (0.9) ✻5.6 (1.1) ✻4.8 (1.5) ✻0.7 (0.2) ✻2.8 (1.4) ✻4.1 (1.9) Time to 1st AP (ms) (SEM) 308.3 (0.1) 376.8 (0.1) 387.4 (0.1) 40.2 (0.01) 366 (0.2) 605 (0.01). Conclusion: The PulStar−, regardless of thrust magnitude, yielded similar changes in mean MF and mean MIF values suggesting a possible ceiling effect on muscle spindle discharge. With the Activator V− instrument, changes in both mean MF and mean MIF were graded with thrust magnitude. This is the first report about the effects of clinically used manipulation instruments on paraspinal muscle spindle activity. Further investigation is needed to extend these findings and to determine any clinical significance. This work was supported by NIH grant K01AT005935 to WRR and instruments were kindly provided by Sense Technology Inc. and Activator Methods®. Source: Reed William and Pickar Joel. The Journal of Alternative and Complementary Medicine. May 2014, 20(5): A28-A28. doi:10.1089/acm.2014.5068.abstract.
Posted on: Fri, 24 Oct 2014 09:45:21 +0000