Little is known\u00a0 about the dynamics of spinal manipulation and mechanical force manually\u00a0 assisted short lever adjustments in particular. The purpose of this\u00a0 study is to quantify the biomechanical response to impulsive loads\u00a0 applied over the cervical spine. A previous study had enabled us to\u00a0 quantify the response for the lumbar spine. This would enable the\u00a0 estimation of the internal motion and loading that occurs due to the\u00a0 instrument delivered short lever chiropractic adjustment.<\/p>\n
An anthropomorphic model of the human\u00a0 body has been constructed for this study. The Activator Adjusting\u00a0 Instrument, a product of Activator Methods Inc, (Phoenix, AZ), is used\u00a0 to produce the impulsive loads. The elements of the model involve bones,\u00a0 ligaments, intervertebral discs and muscles which are constructed from\u00a0 composite materials that closely mimic the passive properties of the\u00a0 physiological systems. The instrumentation includes displacement,\u00a0 acceleration and pressure transducers. The sampling rate of the data was\u00a0 1,o00 Hz and filtering of the data is done using software.<\/p>\n
The anthropomorphic model has been\u00a0 used in a previous study to study the dynamics of spinal manipulation in\u00a0 the lumbar spine. It has been found to be a reasonable substitute for\u00a0 the human spine, in terms of the mechanical responses to forces and\/or\u00a0 torques. The present study involved data collection in the cervical\u00a0 spine at the levels of C1, C2, C5 and C6. Preliminary data analysis has\u00a0 been done and the movement response to applied thrusts on the spine has\u00a0 been done qualitatively and a quantitative analysis is expected to be\u00a0 done on data in the near future.<\/p>\n
Anthropomorphic modeling may prove useful\u00a0 in understanding the dynamics of spinal manipulation, particularly when\u00a0 integrated with computer modeling and in vivo studies. Acknowledgement: This study was funded by the National Institute of Chiropractic Research.<\/p>\n
Reference: <\/strong>Sridhar Venkataraman, BS, Gary T. Yamaguchi,\u00a0 PhD, Paul J. Osterbauer, OG, and Arlan W. Fuhr .DC, Arizona State\u00a0 University, Tempe. AZ, The National Institute of Chiropractic Research,\u00a0 Phoenix. AZ; Evaluating Mechanical Force Manually Assisted Short Lever\u00a0 adjusting using an Anthropomorphic model; In: The proceedings of the\u00a0 FCER\u2019s 1993 International Conference on Spinal Manipulation, Montreal,\u00a0 Quebec, Canada, April 30-May 1, Page 13.<\/p>\n