Lumbrical muscle with an additional origin in the forearm

Area of Science:

• Anatomy
• Human Anatomy
• Musculoskeletal System

Background:

• Lumbrical muscle attachment variations are common but rarely documented in Chinese populations.
• This study reports the first case of lumbrical muscle anomaly in a Chinese cadaver.

Purpose of the Study:

• To document an unusual lumbrical muscle variation in a Chinese cadaver.
• To investigate potential clinical implications of this anatomical anomaly.

Main Methods:

• Examination of the upper extremities of 26 Chinese cadavers.
• Detailed dissection and analysis of lumbrical muscle origins and insertions.

Main Results:

• A rare bipennate first lumbrical muscle with an additional origin from the distal forearm was identified in one male Chinese cadaver.
• This anomalous muscle originated from the flexor digitorum profundus distal to the flexor retinaculum.
• All other intrinsic hand muscles in the 26 cadavers exhibited normal anatomy.

Conclusions:

• Anomalous forearm origin of lumbrical muscles can potentially cause median nerve compression.
• This anatomical variation highlights the importance of considering atypical muscle origins in carpal tunnel syndrome diagnosis.