COC Anatomy & Biomechanics 1 — Questions and Answers
Question 1: Which muscle group is primarily responsible for controlling dorsiflexion during the swing phase of gait?
- Tibialis anterior (Correct answer)
- Gastrocnemius
- Soleus
- Peroneus longus
Correct answer: Tibialis anterior
The tibialis anterior contracts eccentrically during loading response and concentrically during swing to clear the foot.
Question 2: The center of mass in a typical adult is located approximately at which anatomical landmark?
- Second sacral vertebra (Correct answer)
- L4-L5 disc
- Greater trochanter
- Anterior superior iliac spine
Correct answer: Second sacral vertebra
The center of mass is typically located just anterior to the second sacral vertebra in the standing position.
Question 3: During normal gait, how many degrees of ankle plantarflexion occur at initial contact in a healthy adult?
- 0–5° (Correct answer)
- 10–15°
- 20–25°
- 30–35°
Correct answer: 0–5°
At initial contact the ankle is near neutral with only 0–5° of plantarflexion in normal gait.
Question 4: Which nerve innervates the intrinsic muscles of the foot responsible for toe flexion?
- Medial plantar nerve (Correct answer)
- Deep peroneal nerve
- Sural nerve
- Saphenous nerve
Correct answer: Medial plantar nerve
The medial plantar nerve (a branch of the tibial nerve) innervates most intrinsic foot muscles including the flexor digitorum brevis.
Question 5: The Q-angle is measured between which two anatomical reference lines?
- Line from ASIS to patella and line from patella to tibial tubercle (Correct answer)
- Line from ASIS to medial joint line and tibia shaft
- Line from greater trochanter to patella and tibial shaft
- Line from iliac crest to fibular head and foot axis
Correct answer: Line from ASIS to patella and line from patella to tibial tubercle
The Q-angle is formed by the line from the ASIS to the patella center and the line from the patella center to the tibial tubercle.
Question 6: Which gait deviation is most commonly associated with hip abductor weakness on the stance-side limb?
- Trendelenburg gait (Correct answer)
- Steppage gait
- Antalgic gait
- Circumduction gait
Correct answer: Trendelenburg gait
Trendelenburg gait causes the pelvis to drop contralaterally during single-limb stance due to weak ipsilateral hip abductors.
COC Anatomy & Biomechanics 1
Which muscle group is primarily responsible for controlling dorsiflexion during the swing phase of gait?