How is a hammertoe defined?

A hammertoe is characterized by a specific deformity of the toe that typically involves the proximal interphalangeal joint. In this condition, the toe is bent downwards at this joint, placing it in a plantarflexed position. This results in the middle joint of the toe being flexed, while the other joints may remain normal or could be extended, which creates the 'hammertoe' appearance.

Understanding the mechanics of a hammertoe is crucial for effective treatment and orthotic design. When the toe is plantarflexed at the proximal interphalangeal joint, it can lead to discomfort and difficulty in wearing shoes, as the toe may rub against the shoe, leading to calluses or blisters. Addressing this issue involves not only correcting the alignment but also considering footwear modifications to alleviate pressure on the affected joint.

In contrast, the descriptions in the other options do not accurately represent the characteristic position of a hammertoe, which is primarily defined by its plantarflexed position at the proximal interphalangeal joint.