The Relationship between the Heel Buttress of the Hoof and the Orientation of the Distal Phalanx
Authors: Martin
Journal: FWCF Fellowship Thesis
Summary
# Editorial Summary: Heel Buttress Angle and Distal Phalanx Orientation Whilst the palmar angle of the distal phalanx remains a standard reference for assessing foot balance on lateromedial radiographs, growing anecdotal evidence suggests that lower heel angles predispose horses to palmar third lameness. Martin's Fellowship thesis investigated whether external hoof measurements correlate with pedal bone orientation by comparing pre- and post-trim external hoof dimensions against radiographic measurements in 15 sound warmblood showjumpers. The research revealed a significant moderate correlation between heel angle and palmar angle (r=0.42–0.47, p≤0.021), though this weakened following standardised trimming; crucially, heel length showed no meaningful relationship with palmar angle, yet heel angle demonstrated a substantially stronger correlation with the solear parietal angle (r=0.55–0.60, p<0.001). For practitioners, this finding challenges the common assumption that heel length dictates pedal bone alignment, instead positioning heel buttress angle as a more reliable indicator of proper distal phalanx orientation and suggesting that the solear parietal angle warrants greater attention in radiographic assessment of foot balance.
Practical Takeaways
- •Focus on heel buttress angle rather than heel length when assessing foot balance and distal phalanx orientation during trimming
- •A more upright heel angle is associated with better pedal bone alignment and may reduce risk of palmar foot lameness
- •Solear parietal angle may be a more reliable radiographic indicator than palmar angle for monitoring heel quality and distal phalanx orientation
Key Findings
- •Significant moderate correlation between heel angle and palmar angle in pre-trimmed state (medial p=0.021 r=0.420, lateral p=0.010 r=0.465), which weakened after trimming
- •Strong significant correlation between heel angle and solear parietal angle (medial p=0.001 r=0.554, lateral p=<0.001 r=0.603)
- •No significant correlation between heel length and palmar angle or solear parietal angle
- •More upright heel buttress angle indicates positive distal phalanx orientation; heel length should not be used as marker for pedal bone alignment