Which of the following muscles is primarily responsible for pointing the toe (plantar flexion of the foot)?

• A. Biceps femoris
• B. Gastrocnemius
• C. Rectus femoris
• D. Tibialis anterior

Answer: (B)

Verified step by step guidance

1. Understand the action described in the question: Plantar flexion refers to the movement of the foot where the toes point downward, as in pressing a gas pedal or standing on tiptoes.
2. Identify the muscle groups involved in plantar flexion: The primary muscles responsible for this action are located in the posterior compartment of the lower leg, including the gastrocnemius and soleus muscles.
3. Analyze the options provided: The biceps femoris is a muscle of the posterior thigh involved in knee flexion and hip extension, not plantar flexion. The rectus femoris is part of the quadriceps group and primarily extends the knee. The tibialis anterior is located in the anterior compartment of the leg and is responsible for dorsiflexion (lifting the toes upward), which is the opposite of plantar flexion.
4. Focus on the gastrocnemius: This muscle is part of the calf and works with the soleus to perform plantar flexion. It attaches to the heel via the Achilles tendon and is activated during movements like pointing the toes.
5. Conclude that the gastrocnemius is the correct answer based on its anatomical location and function in plantar flexion.