DPM Clinical Biomechanics

Question 1

Which joint primarily allows inversion and eversion of the foot?

Accepted Answer

Subtalar joint

Answer

The subtalar joint, located between the talus and calcaneus bones in the foot, is primarily responsible for the complex movements of inversion and eversion. Inversion involves turning the sole of the foot inward, while eversion turns it outward. These movements are crucial for adapting the foot to uneven surfaces and maintaining balance during walking and running.

Question 2

During gait, what is the primary role of the tibialis posterior muscle?

Accepted Answer

Arch stabilization and inversion

Answer

The tibialis posterior muscle is a deep posterior compartment muscle of the leg, crucial for foot stability. Its primary roles include inverting the foot and assisting in plantarflexion. Most importantly, it provides dynamic support to the medial longitudinal arch, preventing excessive pronation and maintaining the foot's structural integrity during weight-bearing activities like gait.

Question 3

Which phase of gait is most associated with maximum ankle dorsiflexion?

Accepted Answer

Midstance

Answer

During the midstance phase of gait, the body's center of gravity passes directly over the supporting foot. As the tibia continues to advance forward over the stationary foot, the ankle joint reaches its maximum degree of dorsiflexion. This allows for smooth forward progression and prepares the foot for the subsequent push-off phase.

Question 4

What motion occurs at the first ray during propulsion?

Accepted Answer

Plantarflexion

Answer

During the propulsion phase of gait, as the heel lifts and the body pushes off, the first ray (comprising the first metatarsal and medial cuneiform) undergoes plantarflexion. This motion, along with hallux dorsiflexion, helps to 'lock' the midfoot and create a rigid lever. This rigidity is essential for efficient transfer of force and powerful push-off from the ground.

Question 5

Which foot deformity is characterized by hindfoot valgus and forefoot abduction?

Accepted Answer

Adult-acquired flatfoot

Answer

Adult-acquired flatfoot, often linked to posterior tibial tendon dysfunction, is characterized by a progressive collapse of the medial longitudinal arch. This collapse leads to a distinctive combination of hindfoot valgus (eversion) and forefoot abduction (splaying outwards). These specific deformities are key diagnostic features distinguishing it from other foot conditions.

(DPM) Doctor of Podiatric Medicine Practice Test

(DPM) Doctor of Podiatric Medicine Practice Test

DPM Clinical Biomechanics