Synergistic yet different: Rethinking the gastrocnemii as two functionally distinct muscles

Area of Science:

• Biomechanics
• Human Anatomy
• Neuroscience

Background:

• The medial and lateral gastrocnemius muscles are vital for locomotion and posture.
• They are often treated as a single muscle unit due to shared functions, overlooking potential differences.

Purpose of the Study:

• To review and synthesize evidence differentiating the medial and lateral gastrocnemius muscles.
• To highlight the importance of considering these muscles as distinct entities in research.

Main Methods:

• Re-analysis of previously published data.
• Review of anatomical, neural, and biomechanical evidence.

Main Results:

• Medial and lateral gastrocnemius muscles possess partially independent distal sub-tendons, varying volumes, and architectures.
• Independent neural control suggests distinct neural drives.
• Significant differences in biomechanical behavior, including force production and potential frontal plane torque generation.

Conclusions:

• The medial and lateral gastrocnemius muscles exhibit meaningful differences, supporting their classification as distinct muscles.
• Treating them separately is crucial for accurate biomechanical and modeling studies.
• Understanding these distinctions can improve insights into human movement and sports performance.