Suprascapular entrapment neuropathy: a clinical, anatomical, and comparative study. Part 3: comparative study

Area of Science:

• Comparative anatomy
• Mammalian evolution
• Human anatomy

Background:

• The function of the human suprascapular ligament is not well-defined.
• Previous studies suggest a potential role in upper extremity mechanics.

Purpose of the Study:

• To investigate the functional role of the suprascapular ligament.
• To compare its presence and structure across different mammalian groups.

Main Methods:

• Dissection of the suprascapular region in diverse primate and subprimate species.
• Comparative anatomical analysis of ligamentous structures.

Main Results:

• A distinct pattern emerged: New World primates showed continuity between the suprascapular and coracoclavicular ligaments.
• Old World monkeys and subprimates lacked the suprascapular ligament.
• Human anatomy resembled that of New World primates.

Conclusions:

• The suprascapular ligament's presence and structure correlate with upper extremity function across mammalian groups.
• Its continuity with the coracoclavicular ligament in humans and New World primates may enhance bony attachment area.