Hammer palsy, also known as hammer thumb or mallet finger, refers to a condition that affects the finger's ability to fully extend at the knuckle joint. It is commonly caused by a forceful blow to the fingertips, resulting in tendon damage or rupture. While "hammer palsy" is the most widely used term to describe this condition, there are a few synonyms often employed. These include mallet finger, hammer thumb, and baseball finger. Regardless of the name used, it is important to seek medical attention for proper diagnosis and treatment, as untreated hammer palsy can result in long-term finger deformity and functionality issues.