Movements of vertebrae during manipulative thrusts to unembalmed human cadavers.
OBJECTIVE
The purpose of this study was to measure the relative movements of vertebrae during manipulative thrusts to unembalmed post-rigor mortis human cadavers.


METHODS
The investigation was conducted in the gross anatomy laboratory at the University of Calgary.


METHODS
Two 77-yr-old, unembalmed, post-rigor mortis, male cadavers were used.


METHODS
The movements of vertebrae were investigated by using high-speed cinematography to record the movements of bone pins threaded into T10, T11 and T12 during spinal manipulative therapy to unembalmed post-rigor human cadavers. A single clinician delivered a series of posterior-to-anterior (p-to-a) thrusts to the right transverse process of either T10, T11 or T12, using a reinforced hypothenar contact. Relative p-to-a and lateral translations, as well as axial and sagittal rotations, in T10-T11 and T11-T12 were calculated. Corresponding p-to-a forces exerted by the clinician onto the cadaver were recorded using a pressure pad.


RESULTS
Significant relative movements were measured primarily between the targeted and immediately adjacent vertebrae during the thrusts. Vertebral pairs remained slightly 'hyper-extended' after the rapid thrusts to T11, when the p-to-a forces returned to preload levels.


CONCLUSIONS
These findings may be useful for the understanding of the deformation behavior of the vertebral column during therapeutic manipulation. A fully three-dimensional analysis of all six degrees of freedom, using a larger number of unembalmed cadavers, would be useful in clarifying the relationship between the externally applied forces and the observed relative movement patterns of the vertebrae.
Gál
J
J
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
Herzog
W
W
Kawchuk
G
G
Conway
P J
PJ
Zhang
Y T
YT
D000368:Aged; D001696:Biomechanical Phenomena; D001858:Bone Nails; D002102:Cadaver; D002684:Chiropractic / Q000379:methods*; D004615:Embalming; D006801:Humans; D008297:Male; D009040:Motion Pictures; D009068:Movement / Q000502:physiology*; D016059:Range of Motion, Articular; D012399:Rotation; D013131:Spine / Q000502:physiology*; D013997:Time Factors