Quantification of equine sacral and iliac motion during gait: A comparison between motion capture with skin-mounted and bone-fixated sensors
Article first published online: 8 NOV 2010
© 2010 EVJ Ltd
Equine Veterinary Journal
Special Issue: Proceedings of the 8th International Conference on Equine Exercise Physiology
Volume 42, Issue Supplement s38, pages 468–474, November 2010
How to Cite
GOFF, L., Van WEEREN, P. R., JEFFCOTT, L., CONDIE, P. and McGOWAN, C. (2010), Quantification of equine sacral and iliac motion during gait: A comparison between motion capture with skin-mounted and bone-fixated sensors. Equine Veterinary Journal, 42: 468–474. doi: 10.1111/j.2042-3306.2010.00204.x
- Issue published online: 8 NOV 2010
- Article first published online: 8 NOV 2010
- [Paper received for publication 25.06.10; Accepted 05.07.10]
Reasons for performing study: Information regarding movement at the ilium and sacrum in nonlame horses during normal gait may assist in understanding the biomechanics of the equine sacroiliac joint.
Objectives: To determine the amount and direction of motion at the ilium and sacrum using 3D orientation sensors during walk and trot in sound Thoroughbreds. To compare results from sensors fixed to the skin with results from sensors fixed to bone-implanted pins.
Methods: Three 3D wireless orientation sensors were mounted to the skin over the tuber sacrale (TS) and sacrum of 6 horses and motion at the ilium and sacrum was recorded for lateral bending (LB) flexion-extension (F-E) and axial rotation (AR) during walk and trot. This process was repeated with the orientation sensors mounted to the same pelvic landmarks via Steinmann pins.
Results: Mean walk values were greater than trot values using pin-mounted sensors for all planes of movement (P<0.05). Walk had 1.64 ± 0.22° (mean ± s.e.) more LB than trot (pin-mounted) yet 0.68 ± 0.22° less than trot when skin-mounted; 3.45 ± 0.15° more F-E (pin- and skin-mounted), and 4.99 ± 0.4° more AR (pin-mounted), but trot had 3.4 ± 0.40° more AR than walk with skin mounting. Using pinned sensors for trot resulted in less LB (2.47 ± 0.22°), F-E (1.12 ± 0.15°) and AR (10.62 ± 0.40°); and for walk less F-E (1.12 ± 0.15°) and AR (2.15 ± 0.40°) compared to skin-mounted. Poor correlation existed between mean values for skin- and pin-mounted data for walk and trot, for all planes of motion.
Conclusions: Movements were smaller at trot with bone-fixated sensors compared to walk, suggesting increased muscular control of movement at the trot. The apparent increase in skin motion at the trot and no clear correlation between skin- and bone-mounted sensors indicates inaccuracies when measuring sacral and iliac movement with skin mounting.