The study investigates the effects of acceleration on the kinetic and kinematic measurements of three different gaits in horses: walking, trotting, and cantering. The researchers aim to identify measurements that can distinguish between these gaits during both steady and unsteady movement conditions.

Objective of the Study

• Animals adjust their gait based on their locomotor speed. Thus, the study is concerned with understanding how this varied locomotion impacts traditional measures used to evaluate steady-speed locomotion. In nature, steady state conditions are quite rare; animals frequently accelerate, decelerate, and make turns.
• The researchers collected kinetic and kinematic data from horses performing the three gaits—walking, trotting, cantering—in both steady and unsteady conditions.
• The ultimate objective was to find gait descriptors or variables that could distinguish between the three gaits under all conditions, unaffected or predictably affected by acceleration.

Research Approach

• Existing data on the kinematics and kinetics of horses transitioning between the three gaits were analyzed to determine the effects of acceleration on typical gait descriptors.
• The researchers closely examined variables such as congruity, phase shift, and Center of Mass (COM) velocity angle, work (positive and negative) and energy recovery. These variables ideally would be able to distinguish between gaits during unsteady conditions.

Findings and Conclusions

• The study found that congruity, phase shift, and COM velocity angle did not distinguish between gaits when the dataset included trials in unsteady conditions.
• Variables such as work (positive and negative) and energy recovery appeared to distinguish between gaits and showed a consistent relationship with acceleration.
• Force angle, collision angle, and collision fraction showed a U-shaped relationship with acceleration and were found to be promising tools for future research in studying gaits in unsteady conditions.
• The study also discussed Hodographs, which are graphical representations used to study COM mechanics. While these are interesting, they are descriptive rather than quantitative.