Medial longitudinal arch of the foot is maintained by all except ?
**Core Concept**
The medial longitudinal arch (MLA) of the foot is a critical anatomical structure that plays a vital role in weight-bearing and shock absorption during gait. The MLA is maintained by a combination of bones, ligaments, and muscles that work together to maintain its integrity.
**Why the Correct Answer is Right**
The MLA is primarily maintained by the plantar fascia, a band of fibrous tissue that runs along the bottom of the foot, connecting the calcaneus to the metatarsal bones. Additionally, the MLA is also supported by the cuboid and navicular bones, which provide additional stability and maintain the arch's shape. Furthermore, the tibialis posterior muscle, which originates from the tibia and fibula, plays a crucial role in maintaining the MLA by pulling on the plantar fascia and the navicular bone.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the plantar fascia is indeed a key structure that maintains the MLA, and it is not the correct answer.
**Option B:** This option is incorrect because the cuboid and navicular bones do play a role in supporting the MLA, but they are not the only structures responsible for its maintenance.
**Option C:** This option is incorrect because the tibialis posterior muscle is indeed a key muscle that helps maintain the MLA, and it is not the correct answer.
**Clinical Pearl / High-Yield Fact**
A common cause of MLA collapse is plantar fasciitis, which can be caused by overuse, poor foot biomechanics, or underlying medical conditions such as diabetes or rheumatoid arthritis.
**Correct Answer:** B.