Three-dimensional kinematics of the equine metacarpophalangeal joint using x-ray reconstruction of moving morphology – a pilot study.

This study investigated the movement of the metacarpophalangeal joint (MCPJ) in a pony, using 3D x-ray technology and motion capture. The research showed no significant differences in joint movement or ground reaction forces whether legwear was used or not during jump down exercises.

Methodology

• The researchers used a technique called X-ray reconstruction of moving morphology (XROMM), which combines biplanar videoradiography and computed tomography (CT) scanning to capture 3D bone motion.
• 3D bone models were derived from CT scans and animated using motion capture data from videoradiography, producing a highly accurate visualisation of skeletal movement.
• The MCPJ motion in a healthy pony was analysed under different conditions: without legwear, with a neoprene boot and with a fleece polo wrap.

Findings

• Marker tracking precision was precise, with a 0.09 mm fluctuation for walking and trotting, and 0.10mm during jump exercises.
• The study reported the maximum extension, abduction/adduction (sideways movement), and external/internal rotations of the MCPJ during walk and trot exercises.
• The results show that the MCPJ worked like a stable hinge joint with very little extra sagittal rotation.

Effect of Legwear

• When analysing the impact of protective legwear during the jump down exercise, the team did not observe any substantial changes in MCPJ maximum extension angles or vertical ground reaction force (GRFv), a measure of the force exerted by the ground on the pony’s hoof during movement.
• The researchers compared neoprene boot application and fleece polo wrap application with no legwear (the control). Although they did record variations in the extension and GRFv with each form of legwear, these were not considered significant deviations from the control.

Conclusion

• This initial study demonstrated the potential benefits and practical limitations of using XROMM to document equine MCPJ kinematics.
• The research found no significant impact on MCPJ movement or GRFv from the application of different types of legwear during jump down exercises.