Effect of walking velocity on forelimb kinematics and kinetics
Authors: KHUMSAP S., CLAYTON H. M., LANOVAZ J. L., BOUCHEY M.
Journal: Equine Veterinary Journal
Summary
Establishing baseline biomechanical parameters across varying walking speeds is essential for identifying lameness in horses that cannot maintain consistent velocity during clinical assessment. Khumsap and colleagues collected kinematic and force plate data from five sound horses walking between 0.82–1.91 m/s, measuring forelimb joint kinematics, ground reaction forces (vertical, braking and propulsive), and net joint energies, then used regression analysis to develop predictive equations for normal values at different velocities. As velocity increased, stride length lengthened whilst stance and stride duration shortened; whilst peak vertical, braking and propulsive forces all increased, the total impulses paradoxically decreased due to the reduced time in stance phase, suggesting that these force increases were not driven by increased muscular effort but rather by mechanical adjustment related to head and neck oscillation patterns. The research reveals a counterintuitive biomechanical principle—faster walking produces higher peak forces without greater energy generation at the joints—which has important implications for interpreting force plate data in clinical practice. These regression equations provide practitioners with velocity-adjusted normative data, enabling more accurate detection of subtle lameness by accounting for the speed-dependent changes that occur naturally in sound horses.
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Practical Takeaways
- •Regression equations provided in this study can be used as normative reference values when evaluating lame horses walking at variable speeds, improving diagnostic accuracy
- •Changes in ground reaction forces with speed are biomechanically normal and do not indicate lameness; understanding this prevents misinterpretation of kinetic data in clinical assessment
- •Head and neck position dynamically influences forelimb loading patterns, suggesting these should be observed during lameness evaluation
Key Findings
- •Increased walking velocity correlated with increased stride length and decreased stance duration
- •Peak vertical, braking, and propulsive ground reaction forces increased with velocity despite decreased impulses
- •No significant increase in energy generation at forelimb joints with increased velocity, suggesting muscle activity was not the source of increased forces
- •Longitudinal ground reaction force changes were influenced by velocity-dependent increases in head and neck oscillations