COF Human Anatomy & Physiology 3 — Questions and Answers
Question 1: During the swing phase of gait, which muscle primarily responsible for dorsiflexion must contract concentrically to clear the foot from the ground?
- Gastrocnemius
- Tibialis anterior (Correct answer)
- Peroneus brevis
- Flexor hallucis longus
Correct answer: Tibialis anterior
Tibialis anterior contracts concentrically during swing phase to dorsiflex the ankle and ensure adequate toe clearance.
Question 2: The medial collateral ligament of the knee primarily resists which force?
- Varus stress
- Posterior tibial translation
- Valgus stress (Correct answer)
- Anterior tibial translation
Correct answer: Valgus stress
The medial collateral ligament (MCL) is the primary restraint against valgus stress at the knee joint.
Question 3: Which vertebral level corresponds to the umbilicus dermatome, a key reference in spinal cord injury classification?
- T6
- T10 (Correct answer)
- L1
- T8
Correct answer: T10
T10 dermatomal level corresponds to the umbilicus and is a standard neurological landmark for assessing thoracic spinal cord injuries.
Question 4: What type of joint is the distal tibiofibular syndesmosis?
- Synovial hinge joint
- Fibrous syndesmosis (Correct answer)
- Cartilaginous symphysis
- Synovial pivot joint
Correct answer: Fibrous syndesmosis
The distal tibiofibular joint is a fibrous syndesmosis held together by the anterior and posterior tibiofibular ligaments and the interosseous membrane.
Question 5: The thoracolumbar fascia is biomechanically significant for orthotic management because it:
- Prevents lumbar flexion by acting as a posterior tension band (Correct answer)
- Increases anterior shear forces on lumbar vertebrae
- Directly attaches to the sacral spinous processes
- Limits extension of the hip joint
Correct answer: Prevents lumbar flexion by acting as a posterior tension band
The thoracolumbar fascia functions as a posterior tension band that resists lumbar flexion and transfers loads between the trunk and lower extremities.
Question 6: Which anatomical structure forms the roof of the carpal tunnel through which the median nerve passes?
- Palmar aponeurosis
- Flexor retinaculum (transverse carpal ligament) (Correct answer)
- Dorsal carpal ligament
- Volar plate
Correct answer: Flexor retinaculum (transverse carpal ligament)
The flexor retinaculum (transverse carpal ligament) forms the roof of the carpal tunnel; carpal tunnel syndrome results from compression of the median nerve beneath it.
Question 7: Osteoporosis most significantly affects which type of bone, making vertebral compression fractures more likely in the thoracic and lumbar spine?
- Cortical bone
- Cancellous (trabecular) bone (Correct answer)
- Woven bone
- Lamellar periosteal bone
Correct answer: Cancellous (trabecular) bone
Osteoporosis predominantly reduces cancellous (trabecular) bone density in vertebral bodies, making them susceptible to compression fractures under axial loading.
COF Human Anatomy & Physiology 3
During the swing phase of gait, which muscle primarily responsible for dorsiflexion must contract concentrically to clear the foot from the ground?