CCEP Anatomy & Biomechanics of Extremities 2 — Questions and Answers
Question 1: Which ligament is the primary restraint to anterior translation of the tibia on the femur?
- Posterior cruciate ligament
- Anterior cruciate ligament (Correct answer)
- Medial collateral ligament
- Arcuate ligament
Correct answer: Anterior cruciate ligament
The ACL is the primary restraint to anterior tibial translation, providing approximately 85% of the total restraining force.
Question 2: The 'carrying angle' of the elbow is formed between the long axis of the humerus and which bone?
- Radius
- Ulna (Correct answer)
- Both radius and ulna equally
- Olecranon
Correct answer: Ulna
The carrying angle is measured between the long axis of the humerus and the long axis of the ulna, averaging 5–10° in males and 10–15° in females.
Question 3: During the stance phase of gait, the subtalar joint undergoes which motion to allow the foot to accommodate uneven terrain?
- Supination only
- Pronation only
- Pronation followed by supination (Correct answer)
- No motion occurs
Correct answer: Pronation followed by supination
At initial contact the subtalar joint pronates to absorb shock, then supinates during mid-to-late stance to create a rigid lever for push-off.
Question 4: The coracohumeral ligament primarily limits which motion of the glenohumeral joint?
- Abduction
- External rotation and inferior translation (Correct answer)
- Horizontal adduction
- Flexion beyond 90°
Correct answer: External rotation and inferior translation
The coracohumeral ligament spans from the coracoid process to the greater and lesser tubercles and is a key restraint to external rotation and inferior translation of the humerus.
Question 5: Which tarsal bone articulates with all five metatarsal bases?
- Navicular
- Cuboid (Correct answer)
- Medial cuneiform
- Lateral cuneiform
Correct answer: Cuboid
The cuboid articulates with the 4th and 5th metatarsal bases directly; combined with the three cuneiforms the tarsometatarsal (Lisfranc) joint spans all five metatarsals, but the cuboid is the only tarsal that contacts the lateral two.
Question 6: During shoulder abduction in the scapular plane, the ratio of glenohumeral to scapulothoracic motion is approximately:
- 1:1
- 2:1 (Correct answer)
- 3:1
- 4:1
Correct answer: 2:1
The classic scapulohumeral rhythm is 2:1, meaning for every 3° of arm elevation, 2° occurs at the glenohumeral joint and 1° at the scapulothoracic articulation.
Question 7: The lateral collateral ligament complex of the knee provides primary restraint to which stress?
- Valgus stress
- Varus stress (Correct answer)
- Anterior tibial translation
- Posterior tibial translation
Correct answer: Varus stress
The fibular (lateral) collateral ligament and posterolateral structures are the primary restraints to varus stress at the knee.
CCEP Anatomy & Biomechanics of Extremities 2
Which ligament is the primary restraint to anterior translation of the tibia on the femur?