CCEP Anatomy & Biomechanics of Extremities 3 — Questions and Answers
Question 1: The flexor retinaculum of the ankle forms the roof of the tarsal tunnel; which nerve passes through this tunnel?
- Sural nerve
- Deep peroneal nerve
- Posterior tibial nerve (Correct answer)
- Saphenous nerve
Correct answer: Posterior tibial nerve
The tarsal tunnel contains the posterior tibial nerve (along with the posterior tibial artery and flexor tendons), which divides into medial and lateral plantar nerves distally.
Question 2: The 'screw-home mechanism' of the knee involves which motion occurring at full extension?
- Internal rotation of the tibia
- External rotation of the tibia (Correct answer)
- Anterior translation of the tibia
- Posterior translation of the tibia
Correct answer: External rotation of the tibia
As the knee reaches full extension, the tibia externally rotates (or the femur internally rotates) to lock the joint in the close-packed position.
Question 3: Which muscle of the rotator cuff contributes most to humeral head depression during overhead elevation?
- Supraspinatus
- Infraspinatus
- Subscapularis
- All three — infraspinatus, teres minor, subscapularis equally (Correct answer)
Correct answer: All three — infraspinatus, teres minor, subscapularis equally
The infraspinatus, teres minor, and subscapularis collectively depress the humeral head and counteract the superior shear of the deltoid during elevation.
Question 4: The proximal radioulnar joint is classified as which type of synovial joint?
- Hinge
- Pivot (Correct answer)
- Condyloid
- Plane
Correct answer: Pivot
The proximal radioulnar joint is a pivot (trochoid) joint where the radial head rotates within the annular ligament and the radial notch of the ulna.
Question 5: Tension in the plantar fascia increases with which motion and protects the medial longitudinal arch through the 'windlass mechanism'?
- Plantarflexion of the first MTP joint
- Dorsiflexion of the first MTP joint (Correct answer)
- Inversion of the subtalar joint
- Eversion of the subtalar joint
Correct answer: Dorsiflexion of the first MTP joint
Dorsiflexion of the first MTP joint tightens the plantar fascia like a windlass, raising the medial longitudinal arch and supinating the foot for push-off.
Question 6: The deltoid ligament of the ankle is a strong medial stabilizer; which component primarily resists talar abduction and eversion?
- Anterior talofibular ligament
- Tibiocalcaneal part of the deltoid (Correct answer)
- Tibionavicular part of the deltoid
- Calcaneofibular ligament
Correct answer: Tibiocalcaneal part of the deltoid
The tibiocalcaneal part of the deltoid ligament is the strongest and most important component resisting eversion and abduction of the talus.
Question 7: Which bony landmark is the insertion of the iliotibial band?
- Fibular head
- Gerdy's tubercle (Correct answer)
- Tibial tuberosity
- Lateral femoral epicondyle
Correct answer: Gerdy's tubercle
The iliotibial band inserts at Gerdy's tubercle on the anterolateral proximal tibia, and its friction over the lateral femoral epicondyle causes IT band syndrome.
CCEP Anatomy & Biomechanics of Extremities 3
The flexor retinaculum of the ankle forms the roof of the tarsal tunnel; which nerve passes through this tunnel?