Which muscle eversion of the foot and plantar flexion, inserting at the first metatarsal?

Which muscle eversion of the foot and plantar flexion, inserting at the first metatarsal?

• A. Gastrocnemius
• B. Tibialis Anterior
• C. Fibularis Longus
• D. Soleus

Answer: (C)

The action described—eversion of the foot together with plantar flexion—and insertion at the base of the first metatarsal points to the fibularis longus. This muscle runs from the fibula, passes around the lateral malleolus, and its tendon travels under the foot to attach to the base of the first metatarsal (and the medial cuneiform). When it contracts, it everts the sole (turns the foot outward) and helps push the foot downward at the ankle, contributing to plantar flexion. Other muscles either invert the foot or act primarily as ankle plantar flexors with insertions on the heel (calcaneus), or they evert the foot but insert at a different location (like the 5th metatarsal), so they don’t match both criteria as cleanly.

The action described—eversion of the foot together with plantar flexion—and insertion at the base of the first metatarsal points to the fibularis longus. This muscle runs from the fibula, passes around the lateral malleolus, and its tendon travels under the foot to attach to the base of the first metatarsal (and the medial cuneiform). When it contracts, it everts the sole (turns the foot outward) and helps push the foot downward at the ankle, contributing to plantar flexion. Other muscles either invert the foot or act primarily as ankle plantar flexors with insertions on the heel (calcaneus), or they evert the foot but insert at a different location (like the 5th metatarsal), so they don’t match both criteria as cleanly.