The Extensor Indicis Brevis - A Rare Variation and its Significance

Area of Science:

• Anatomy
• Morphology
• Human Anatomy

Background:

• Muscle attachment variations are significant for understanding rare clinical conditions.
• The extensor indicis muscle plays a key role in index finger extension.

Observation:

• A case report documented an abnormal extensor indicis muscle attachment in the left hand of a male cadaver.
• The muscle originated from the lunate carpal bone and posterior radiocarpal ligament, with a short belly distally attached to the index finger's proximal phalanx.

Findings:

• This specific muscular variation, an abnormal origin of the extensor indicis, has a reported incidence of 1.0% in previous studies.
• Such variations can lead to posterior hand pain and swelling, potentially misdiagnosed as synovial cysts or ganglia.

Implications:

• Awareness of rare extensor indicis muscle variations is vital for clinicians and surgeons.
• Accurate anatomical knowledge aids in precise surgical decision-making and differential diagnosis of hand pain.
• Occupational and physical therapists can benefit from this information for patient management and rehabilitation strategies.