Unipodal stance influences radiographic evaluation of foot balance in horses.

The study confirms that lifting one front leg (unipodal stance) affects the assessment of foot balance in horses when done through radiographic analysis.

Objective of the Research

The objective of this research was to ascertain how a unipodal stance, a commonly used restraint method in horses, affects quantitative radiographic parameters in equine forefeet. This was achieved through an experimental one-group pretest, posttest study on seven non-lame horses.

Methodology

The researchers used the following methodical approach:

• For each horse, Lateromedial (LM) and dorsopalmar (DP) radiographic projections were acquired for both forefeet which were squarely placed on blocks. Two X-ray generators were used for this.
• Radiographs defined by each foot were first obtained in a bipodal (using both front feet) stance, immediately followed by the same radiographic projections acquired while the horse was in a unipodal stance.
• Various measurements were recorded for each stance such as the distal interphalangeal joint (DIPJ) space width on both projections, joint balance, extensor process-to-middle phalangeal condyle distance, and deep digital flexor tendon angle.
• A matched pairs design and Student’s t-test with a 95% confidence level were used to test the statistical significance.

Findings

The study reached the following key findings:

• The unipodal stance significantly reduced the lateral DIPJ space width and to a lesser extent increased the medial DIPJ space width.
• The unipodal stance significantly increased mediolateral joint imbalance.
• There was a significantly higher degree of DIPJ flexion in a unipodal stance.
• The stance should be carefully taken into consideration when measuring radiographic parameters in equine forefeet, especially if assessing foot balance and conformation, as unipodal stance significantly affects the mediolateral balance of the DIPJ on DP radiographs and significantly alters the phalangeal axis on LM radiographs.

In essence, the findings confirm that the way a horse’s forefoot is positioned during radiographic analysis significantly alters the results, specifically regarding foot balance and conformation assessments. The study therefore advises caution in using stance as part of these assessments.