William R Reed1, Randall Sozio2, Joel G Pickar3, Stephen M Onifer4. 1. Associate Professor, Palmer Center for Chiropractic Research, Davenport, IA. Electronic address: william.reed@palmer.edu. 2. Research Associate, Palmer Center for Chiropractic Research, Davenport, IA. 3. Professor Emeritus, Palmer Center for Chiropractic Research, Davenport, IA. 4. Associate Professor, Palmer Center for Chiropractic Research, Davenport, IA.
Abstract
OBJECTIVE: The objective of this preliminary study was to determine if high-velocity, low-amplitude spinal manipulation (HVLA-SM) thrust duration alters mechanical trunk activation thresholds of nociceptive-specific (NS) lateral thalamic neurons. METHODS: Extracellular recordings were obtained from 18 NS neurons located in 2 lateral thalamic nuclei (ventrolateral [n = 12] and posterior [n = 6]) in normal anesthetized Wistar rats. Response thresholds to electronic von Frey anesthesiometer (rigid tip) mechanical trunk stimuli applied in 3 lumbar directions (dorsal-ventral, 45° caudal, and 45° cranial) were determined before and immediately after the delivery of 3 HVLA-SM thrust durations (time control 0, 100, and 400 milliseconds). Mean changes in mechanical trunk activation thresholds were compared using a mixed model analysis of variance. RESULTS: High-velocity, low-amplitude spinal manipulation duration did not significantly alter NS lateral thalamic neurons' mechanical trunk responses to any of the 3 directions tested with the anesthesiometer. CONCLUSIONS: This study is the first to examine the effect of HVLA-SM thrust duration on NS lateral thalamic mechanical response thresholds. High-velocity, low-amplitude spinal manipulation thrust duration did not affect mechanical trunk thresholds.
OBJECTIVE: The objective of this preliminary study was to determine if high-velocity, low-amplitude spinal manipulation (HVLA-SM) thrust duration alters mechanical trunk activation thresholds of nociceptive-specific (NS) lateral thalamic neurons. METHODS: Extracellular recordings were obtained from 18 NS neurons located in 2 lateral thalamic nuclei (ventrolateral [n = 12] and posterior [n = 6]) in normal anesthetized Wistar rats. Response thresholds to electronic von Frey anesthesiometer (rigid tip) mechanical trunk stimuli applied in 3 lumbar directions (dorsal-ventral, 45° caudal, and 45° cranial) were determined before and immediately after the delivery of 3 HVLA-SM thrust durations (time control 0, 100, and 400 milliseconds). Mean changes in mechanical trunk activation thresholds were compared using a mixed model analysis of variance. RESULTS: High-velocity, low-amplitude spinal manipulation duration did not significantly alter NS lateral thalamic neurons' mechanical trunk responses to any of the 3 directions tested with the anesthesiometer. CONCLUSIONS: This study is the first to examine the effect of HVLA-SM thrust duration on NS lateral thalamic mechanical response thresholds. High-velocity, low-amplitude spinal manipulation thrust duration did not affect mechanical trunk thresholds.
Authors: Gert Bronfort; Roni Evans; Alfred V Anderson; Kenneth H Svendsen; Yiscah Bracha; Richard H Grimm Journal: Ann Intern Med Date: 2012-01-03 Impact factor: 25.391
Authors: Dong-Yuan Cao; William R Reed; Cynthia R Long; Gregory N Kawchuk; Joel G Pickar Journal: J Manipulative Physiol Ther Date: 2013-02 Impact factor: 1.437
Authors: William R Reed; Jamie T Cranston; Stephen M Onifer; Joshua W Little; Randall S Sozio Journal: Exp Brain Res Date: 2017-07-07 Impact factor: 1.972