Question

which abdominal muscle is the agonist for trunk flexion?
○ rectus abdominus
○ external obliques
○ transverse abdominus
○ internal obliques

Explanation:

To determine the agonist for trunk flexion among abdominal muscles, we analyze each option:

• Rectus Abdominus: Its primary function is trunk flexion (e.g., crunches), acting as the agonist for this movement.
• External Obliques: Primarily involved in trunk rotation and lateral flexion, not main flexion.
• Transverse Abdominus: Focuses on core stabilization, not trunk flexion.
• Internal Obliques: Also more for rotation/lateral flexion, not primary flexion.

Thus, Rectus Abdominus is the agonist for trunk flexion.

Answer:

A. Rectus Abdominus