DO DO Anatomy and Physiology 1 — Questions and Answers
Question 1: Which muscle is the primary hip flexor and is most frequently implicated in lumbar somatic dysfunction?
- Gluteus maximus
- Piriformis
- Psoas major (Correct answer)
- Quadratus lumborum
Correct answer: Psoas major
The psoas major attaches to L1–L5 vertebral bodies, and its tightness commonly causes lumbar somatic dysfunction.
Question 2: The thoracic inlet is bounded posteriorly, laterally, and anteriorly by which structures?
- T1 vertebra, first rib, manubrium (Correct answer)
- T4 vertebra, second rib, sternum body
- T6 vertebra, third rib, xiphoid
- T12 vertebra, twelfth rib, diaphragm
Correct answer: T1 vertebra, first rib, manubrium
The thoracic inlet is the superior opening of the thorax, bounded by T1 posteriorly, the first rib laterally, and the manubrium anteriorly.
Question 3: Which nerve passes inferior to (or through) the piriformis and is compressed in piriformis syndrome?
- Femoral nerve
- Obturator nerve
- Sciatic nerve (Correct answer)
- Ilioinguinal nerve
Correct answer: Sciatic nerve
The sciatic nerve typically exits inferior to the piriformis; in some individuals it passes through it, making it vulnerable to piriformis compression.
Question 4: The sacrotuberous and sacrospinous ligaments are clinically important in OMM because they perform which function?
- Support the knee joint capsule
- Stabilize the sacroiliac joint and resist excessive sacral nutation (Correct answer)
- Directly connect lumbar vertebrae to the femur
- Form the posterior hip capsule
Correct answer: Stabilize the sacroiliac joint and resist excessive sacral nutation
These two ligaments are primary stabilizers of the SI joint, resisting excessive sacral nutation (forward flexion).
Question 5: The thoracolumbar fascia is significant in OMM because it connects which structures?
- Only thoracic vertebrae to ribs
- Thoracic/lumbar spine to pelvis, gluteal muscles, and upper extremity via latissimus dorsi (Correct answer)
- Cervical spine directly to sacrum
- Abdominal muscles to the femur
Correct answer: Thoracic/lumbar spine to pelvis, gluteal muscles, and upper extremity via latissimus dorsi
The thoracolumbar fascia is a broad connective tissue sheet integrating the spine, pelvis, gluteals, and upper body muscles into a force-transfer unit.
Question 6: The dorsal horn of the spinal cord processes which types of afferent signals most relevant to somatic dysfunction?
- Motor commands only
- Nociception and proprioception from musculoskeletal tissues (Correct answer)
- Autonomic efferent commands
- Endocrine regulatory signals
Correct answer: Nociception and proprioception from musculoskeletal tissues
The dorsal horn processes incoming pain (nociception) and position sense (proprioception) signals from muscles, joints, and skin.
DO DO Anatomy and Physiology 1
Which muscle is the primary hip flexor and is most frequently implicated in lumbar somatic dysfunction?