A deformity where one or more toes bend downward at the middle joint.
To support a 10% rating, medical records and examination findings would need to show that all toes on the affected foot have hammer toe deformity and that claw foot is not present. A VA or private examination that documents the number of toes involved and confirms the absence of claw foot directly addresses both criteria. Imaging such as X-rays can help confirm the structural deformity across all toes. For a single affected toe, the record would reflect only one toe involved, which corresponds to the 0% rating. Statements from you describing how the deformity affects your ability to walk, wear standard footwear, or perform daily activities can provide useful context, but the rating itself turns on the clinical findings showing which toes are affected and whether claw foot is present.
Conditions that are often caused or made worse by this one. If you have any of these, they may be claimable as secondary service connection.