Which of the following muscles does not act in plantar flexion?

• A. Tibialis anterior
• B. Plantaris
• C. Gastrocnemius
• D. Soleus

Answer: (A)

Verified step by step guidance

1. Understand the concept of plantar flexion: Plantar flexion is the movement that decreases the angle between the sole of the foot and the back of the leg, such as when standing on tiptoes.
2. Identify the muscles involved in plantar flexion: The primary muscles responsible for plantar flexion are the gastrocnemius, soleus, and plantaris. These muscles are located in the posterior compartment of the leg.
3. Analyze the function of each muscle: The gastrocnemius and soleus are powerful muscles that contribute significantly to plantar flexion. The plantaris, although smaller, also assists in this movement.
4. Consider the tibialis anterior: This muscle is located in the anterior compartment of the leg and is primarily responsible for dorsiflexion, which is the opposite movement of plantar flexion.
5. Conclude which muscle does not act in plantar flexion: Based on the functions of the muscles, the tibialis anterior does not participate in plantar flexion, as it is involved in dorsiflexion instead.