Anatomy & Physiology Flashcards

What part of the foot is responsible for weight-bearing during walking?

Answer: Metatarsals

The metatarsals are the five long bones located in the midfoot, connecting the tarsal bones to the phalanges (toes). During walking, these bones, particularly the heads of the metatarsals, bear a significant portion of the body's weight, especially during the push-off phase of gait. They play a crucial role in distributing pressure and providing leverage for movement.

What is the primary function of the tibialis posterior muscle in the lower leg?

Answer: Plantarflexion and inversion of the foot

The tibialis posterior muscle is a deep muscle in the posterior compartment of the lower leg. Its primary actions are plantarflexion (pointing the foot downwards) and inversion (turning the sole of the foot inwards). It is also a key stabilizer of the medial longitudinal arch of the foot, helping to maintain its structure and function.

What is the role of the flexor hallucis longus in foot movement?

Answer: Plantarflexion and toe flexion

The flexor hallucis longus muscle originates from the fibula and inserts into the great toe. Its main functions are to powerfully flex the great toe (hallux) and assist in plantarflexion of the ankle. This muscle is particularly active during the push-off phase of walking and running, providing propulsion.

Which of the following bones form the arch of the foot?

Answer: Talus and calcaneus

The talus and calcaneus (heel bone) are two of the seven tarsal bones that form the posterior part of the foot. These bones, along with other tarsals and metatarsals, articulate to create the complex structure of the foot's arches. The talus sits atop the calcaneus, forming a critical part of the ankle joint and the longitudinal arches, which are essential for weight distribution and shock absorption.

What is the primary function of the plantar fascia in the foot?

Answer: Supports the arch and absorbs shock

The plantar fascia is a thick band of connective tissue running along the bottom of the foot, from the heel bone to the toes. Its primary function is to support the medial longitudinal arch of the foot, preventing it from flattening during weight-bearing. It also acts as a crucial shock absorber, distributing forces across the foot during activities like walking and running.

What muscle is primarily responsible for dorsiflexion of the foot?

Answer: Tibialis anterior

The tibialis anterior is a prominent muscle located on the front of the lower leg. Its main action is dorsiflexion of the foot, which means lifting the foot upwards towards the shin. It also contributes to inversion of the foot and is essential for preventing foot drop during walking, ensuring the toes clear the ground.

Which ligament is responsible for preventing over-pronation of the foot?

Answer: Spring ligament

The spring ligament, also known as the plantar calcaneonavicular ligament, is a broad, thick ligament located on the medial side of the foot. It connects the calcaneus to the navicular bone and plays a critical role in supporting the head of the talus and maintaining the medial longitudinal arch. Its integrity is crucial in preventing excessive pronation (flattening) of the foot.

What is the primary action of the peroneus longus muscle?

Answer: Eversion and plantarflexion of the foot

The peroneus longus (also known as fibularis longus) muscle is located on the lateral side of the lower leg. Its primary actions are eversion of the foot (turning the sole outwards) and assisting in plantarflexion (pointing the foot downwards). It also helps to stabilize the ankle and support the transverse and lateral longitudinal arches of the foot.

What structure provides the connection between the tibia and fibula?

Answer: Syndesmosis joint

A syndesmosis joint is a type of fibrous joint where two bones are joined by a strong ligament or interosseous membrane, allowing for very little movement. The connection between the tibia and fibula in the lower leg, specifically at the distal tibiofibular joint, is a syndesmosis. This strong connection is vital for the stability of the ankle joint.