Multiplanar intersegmental angular velocity in the assessment of topline movement in horses

To measure intersegmental movement in the sagittal, dorsal, and transverse planes of the cranial thoracic to caudal thoracic, caudal thoracic to lumbar, and lumbar to sacral segments using range of motion and angular velocity as measures of quality of movement.

6-degrees-of-freedom spinal motion was measured at the walk and trot in 3 sound Thoroughbred and Thoroughbred cross horses, and the data were pooled, giving a total of 54 gait cycles at walk and 33 at trot. These were compared against 8 cycles at walk and 13 at trot from 1 Thoroughbred horse that was confirmed as having moderate to severe impact and push-off lameness in the right hind limb.

Both joint angles and angular velocities detected differences between the sound horses and the lame horse, with angular velocity showing notably greater differences in absolute values and percentages compared with joint angles.

The between-group differences indicated decreased quality of movement/control in the lame horse, and this was most apparent when trotting.

Intersegmental angular velocity is measured noninvasively and may be used to assess the quality of intersegmental movement in horses as it does in humans. Further investigation to assess angular velocity throughout treatment of topline dysfunction of the horse and its association with different lameness patterns is warranted.