Measurements of bone strain in foals with altered foot balance.

The research study explores the effects of altering foot balance on bone strain in newborn foals. It found that while imbalances initially caused a shift in compressive forces, these changes gradually returned to normal levels over the course of 10 days.

Research Methodology

• The study began shortly after birth, within 2 to 7 days, with a total of 9 foals participating.
• The foals were anesthetized and strain gauges were applied to specific parts of the forelimb: the lateral and medial aspects of the third metacarpal bone, and for 5 foals, on the radius of the forelimb.
• After 4 to 6 days of gauge placement, the foals were made to walk in sets of 10 to 20 strides, and the compressive and tensile strains on the bones beneath the gauges were recorded.
• The researchers then fitted a wedge to the hoof of the limb with the strain gauges, raising the lateral bearing surface and noted the new strain recordings.
• This process continued for 10 days, recording strain gauges every 2 to 3 days.

Key Findings

• Initial data showed that at a normal walk, the compressive strain was higher than the tensile strain in the third metacarpal bone, particularly on the medial side, which bore roughly double the strain of the lateral surface.
• Immediately after application of the wedge, the strain values from the medial surface of the third metacarpal bone decreased by 40%, and the opposite lateral surface saw an increase in compressive strain by 100%.
• These changes reversed over the 10-day period, returning to base-line values, with no significant difference noted. Similar trends were observed in the radius, however, the changes were less noticeable.

Conclusion

• This study found that alterations in hoof balance, while initially affecting strain in the limb bones, had no lasting impact. The medial side of the bones, which naturally carries more compressive strain, quickly restored to its original strain levels.
• This suggests that newborn foals have an innate ability to adapt and maintain normal parameters when faced with imbalance conditions.