COC Anatomy & Biomechanics 3

Question 1

Which of the following best describes the moment arm for the Achilles tendon at the ankle joint?

Accepted Answer

The perpendicular distance from the ankle axis to the line of tendon force

Answer

A moment arm is always the perpendicular distance from the joint axis to the line of action of the force, determining mechanical advantage.

Question 2

In a transfemoral amputee, which hip motion is most limited by the absence of the distal limb segment?

Accepted Answer

Terminal swing extension

Answer

Without the inertia of the distal limb and knee extension, terminal swing hip extension is reduced, often shortening step length.

Question 3

The obliquity of the metatarsophalangeal break line affects prosthetic foot design primarily by influencing:

Accepted Answer

Roll-over shape and mediolateral stability during push-off

Answer

The MTP break line angle determines how smoothly load transfers across the forefoot, affecting roll-over shape and lateral stability.

Question 4

Spasticity in the lower extremity is a velocity-dependent increase in which reflex?

Accepted Answer

Tonic stretch reflex

Answer

Spasticity is defined as a velocity-dependent increase in tonic stretch reflexes, resulting from upper motor neuron lesions.

Question 5

Which of the following joints is considered the 'key link' in the kinetic chain for transferring force from the foot to the hip?

Accepted Answer

Knee joint

Answer

The knee is considered the key link because it must both absorb shock and provide stability while transmitting forces between the ankle and hip.

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