The assessment of the effect of frog support pads and packing upon the palmar angle of the distal phalanx
Authors: Casserly
Journal: FWCF Fellowship Thesis
Summary
# Editorial Summary: Frog Support Pads and Palmar Angle Under-run heels combined with long toes, thin soles and weak walls represent some of the most persistent challenges in farriery, often accompanied by palmar rotation of the distal phalanx that compromises the foot's structural integrity. Casserly's 2018 fellowship study compared radiographic outcomes in 18 horses over eleven months, with nine horses shod with frog support pads and medicated packing whilst nine control horses received standard farriery, measuring palmar angle, heel depth, sole depth and navicular depth at five intervals. Although the control group exhibited significantly greater palmar angles than the treatment group (p=0.016), neither group showed statistically significant changes in palmar angle over the study period; however, the treatment group demonstrated approximately double the improvement in heel depth, sole depth and navicular depth compared to controls, with no measurable improvement in these parameters for unsupported feet. These findings suggest that whilst frog support pads with medicated packing may not dramatically alter the palmar angle itself, they consistently improve the foot's geometric architecture—particularly crucial parameters for load distribution and pressure relief in compromised feet. For practitioners managing chronically weak feet, these results indicate that frog support represents a valuable tool for incrementally restoring functional depth and structure, even when addressing long-standing palmar deviations proves mechanically limited. The clinical significance lies not in dramatic angle correction but in the measurable geometric restoration that supports the foot's ability to function and potentially prevent further deterioration.
Practical Takeaways
- •Frog support pads with medicated packing show promise for improving sole and heel depth in compromised feet, though radiographic improvements in palmar angle alone may not be the primary benefit
- •Consider these devices as part of a longer-term rehabilitation strategy for collapsed heels, as measurable improvements took 11 months and were modest
- •Radiographic measurements at 35-day shoeing intervals may be insufficient to demonstrate clinically meaningful changes in foot conformation; longer observation periods may be needed
Key Findings
- •Palmar angle was significantly greater in the control group than the treatment group (p=0.016), indicating frog support pads with medicated packing did not significantly improve palmar angle over 11 months
- •Treatment group showed approximately double the improvements in sole depth, heel depth, and navicular depth compared to control group, though changes were not statistically significant
- •No statistically significant change in palmar angle occurred across five measurement occasions in either treatment or control group over the study period