Evaluation of equine locomotion during different degrees of experimentally induced lameness. I: Lameness model and quantification of ground reaction force patterns of the limbs.

The research article focuses on the examination of horse locomotion during varying degrees of artificial lameness designed through an experimental model. It highlights the use of force plate data from walking horses and discussions around ground reaction force patterns of the horse limbs under controlled conditions.

Study Design and Experimentation

• The research took into account a selection of six horses, introducing varying degrees of pressure-induced lameness in either a forelimb or a hindlimb. This was achieved by altering the tightness of screws in specially designed horseshoes, essentially manipulating the horses’ comfort levels within a 2-hour frame.
• The scientists then recorded and analyzed the Ground Reaction Force (GRF) patterns, which relate to the movement forces between the foot and ground during locomotion. These patterns were studied across various sessions, compared with the same horse’s control data (data recorded under normal, pain-free circumstances), and with the ‘standard’ – the expected GRF recordings from an average horse of the same breed.

Measurements and Findings

• 93 Ground Reaction Force parameters were identified and used in this extensive quantitative evaluation procedure. The results were crucial in determining the subtle and major changes in the locomotive patterns during different degrees of induced lameness.
• For mild and moderate lameness, the H(orse)INDEX method was effectively used. This method requires comparison with ‘standard’ GRF data of horses of the same breed, serving to differentiate the levels of lameness accurately.
• For subtle changes that were hard to discern visibly, such as minor lameness at trotting speed or nerve blocking of moderate lameness at walking speed, the research used the C(ontrol)INDEX method. This involved a comparison with the control GRF parameters recorded for that specific horse before the induction of lameness.
• The implication of this is the ability to objectively demonstrate minor alterations and shifts in the locomotion patterns that are clinically hard to detect. This contributes significantly to improving diagnosis and treatment procedures for lameness conditions in horses.

Conclusion

The study emphasizes the potential of examining Ground Reaction Force patterns in the identification and differentiation of degrees of lameness in horses. With specific models and methodologies, even minor, clinically unnoticed changes can be traced, analyzed, and understood better. Such research holds promise for advancing veterinary care in equine species, especially in their locomotion conditions.