Effects of vertebral mobilization and manipulation on kinematics of the thoracolumbar region.
OBJECTIVE
To measure passive spinal movements induced during dorsoventral mobilization and evaluate effects of induced pain and spinal manipulative therapy (SMT) on passive vertebral mobility in standing horses.


METHODS
10 healthy adult horses.


METHODS
Baseline vertical displacements, applied force, stiffness, and frequency of the oscillations were measured during dorsoventral spinal mobilization at 5 thoracolumbar intervertebral sites. As a model for back pain, fixation pins were temporarily implanted into the dorsal spinous processes of adjacent vertebrae at 2 of the intervertebral sites. Vertebral variables were recorded again after pin placement and treadmill locomotion. In a randomized crossover study, horses were allocated to control and treatment interventions, separated by a 7-day washout period. The SMT consisted of high-velocity, low-amplitude thrusts applied to the 3 non-pin-placement sites. Control horses received no treatment.


RESULTS
The amplitudes of vertical displacement increased from cranial to caudal in the thoracolumbar portion of the vertebral column. Pin implantation caused no immediate changes at adjacent intervertebral sites, but treadmill exercise caused reductions in most variables. The SMT induced a 15% increase in displacement and a 20% increase in applied force, compared with control measurements.


CONCLUSIONS
The passive vertical mobility of the trunk varied from cranial to caudal. At most sites, SMT increased the amplitudes of dorsoventral displacement and applied force, indicative of increased vertebral flexibility and increased tolerance to pressure in the thoracolumbar portion of the vertebral column.
Haussler
Kevin K
KK
Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Hill
Ashley E
AE
Puttlitz
Christian M
CM
McIlwraith
C Wayne
CW
D000818:Animals; D001696:Biomechanical Phenomena; D018592:Cross-Over Studies; D005260:Female; D006736:Horses / Q000502:physiology*; D008297:Male; D026201:Musculoskeletal Manipulations / Q000379:methods / Q000662:veterinary*; D010146:Pain / Q000662:veterinary; D059408:Pain Management; D013131:Spine / Q000502:physiology*