Methodology and validity of assessing kinematics of the thoracolumbar vertebral column in horses on the basis of skin-fixated markers.
OBJECTIVE
To determine the validity of using skin-fixated markers to assess kinematics of the thoracolumbar vertebral column in horses.


METHODS
5 Dutch Warmblood horses without abnormalities of the vertebral column.


METHODS
Kinematics of T6, T10, T13, T17, L1, L3, L5, S3, and both tuber coxae were determined by use of bone-fixated and skin-fixated markers. Three-dimensional coordinate data were collected while horses were walking and trotting on a treadmill. Angular motion patterns were calculated and compared on the basis of 2-dimensional analysis of data from skin-fixated markers and 3-dimensional analysis of data from bone-fixated markers.


RESULTS
Flexion-extension of thoracolumbar vertebrae and axial rotation of the sacrum were satisfactorily determined at both the walk and trot, using skin-fixated markers. Data from skin-fixated markers were accurate for determining lateral bending at the walk in the midthoracic and lower lumbar portion of the vertebral column only. However, at the trot, data from skin-fixated markers were valid for determining lateral bending for all thoracolumbar vertebrae.


CONCLUSIONS
Caution should be taken when interpreting data obtained by use of skin-fixated markers on lateral bending motions during the walk in horses. For determination of other rotations at the walk and all rotations at the trot, use of skin-fixated markers allows valid calculations of kinematics of the vertebral column. Understanding to what extent movements of skin-fixated markers reflect true vertebral motion is a compulsory step in developing noninvasive methods for diagnosing abnormalities of the vertebral column and related musculature in horses.
Farber
M
M
Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Schamhardt
H
H
van Weeren
R
R
Barneveld
A
A
D000818:Animals; D001696:Biomechanical Phenomena; D006736:Horses / Q000502:physiology*; D008159:Lumbar Vertebrae / Q000502:physiology; D012399:Rotation; D012447:Sacrum / Q000502:physiology; D013131:Spine / Q000502:physiology*; D013904:Thoracic Vertebrae / Q000502:physiology