CBP CBP Spinal Physics and Mechanics 2 — Questions and Answers
Question 1: In CBP, which spinal region is considered to have the greatest influence on global sagittal balance?
- Cervical spine
- Thoracic spine
- Lumbar spine
- Sacral base angle (Correct answer)
Correct answer: Sacral base angle
The sacral base angle is foundational in CBP sagittal balance assessment because it sets the foundation for lumbar lordosis and cascades to affect all superior spinal curves.
Question 2: What is the CBP-defined normal lumbar lordosis Cobb angle (L1–L5)?
- 20–30 degrees
- 40–60 degrees (Correct answer)
- 30–40 degrees
- 60–70 degrees
Correct answer: 40–60 degrees
CBP identifies the normal lumbar lordosis (L1–L5 Cobb) as approximately 40–60 degrees, aligned with the ideal load-bearing geometry of the lumbar spine.
Question 3: Which type of stress is most elevated in intervertebral discs when axial rotation and flexion are combined?
- Pure compressive stress
- Tensile stress on the annular fibers (Correct answer)
- Hydrostatic pressure only
- Shear stress exclusively
Correct answer: Tensile stress on the annular fibers
Combined axial rotation with flexion places the highest tensile stress on the posterior-lateral annular fibers, a mechanism associated with disc herniation.
Question 4: In CBP biomechanics, what is the functional significance of the thoracic kyphosis angle?
- It has no direct relationship to cervical or lumbar curves
- It must be balanced with lumbar lordosis and cervical lordosis to maintain global sagittal alignment (Correct answer)
- It only affects respiratory function
- It is fixed after skeletal maturity and cannot be changed
Correct answer: It must be balanced with lumbar lordosis and cervical lordosis to maintain global sagittal alignment
Thoracic kyphosis angle is integral to global sagittal balance; changes in thoracic kyphosis directly compensate for or worsen cervical and lumbar curve deviations.
Question 5: Which force vector is the primary focus when CBP clinicians design a spinal traction setup?
- Lateral shear only
- The vector that opposes the measured postural displacement (mirror image vector) (Correct answer)
- Always a vertical distraction force
- A rotational torque toward the convexity
Correct answer: The vector that opposes the measured postural displacement (mirror image vector)
CBP traction setups are engineered to apply the mirror image corrective force vector—directly opposing the specific displacement quantified on the patient's radiograph.
Question 6: What does 'global translatory position' refer to in CBP postural analysis?
- The rotation of individual vertebrae around the Y-axis
- The horizontal displacement of the head or trunk relative to the pelvis in the sagittal or frontal plane (Correct answer)
- The degree of disc degeneration across all lumbar levels
- The total range of motion available in the spine
Correct answer: The horizontal displacement of the head or trunk relative to the pelvis in the sagittal or frontal plane
Global translatory position measures how far a spinal region (or the head) has shifted horizontally from its ideal alignment position over the pelvis.
CBP CBP Spinal Physics and Mechanics 2
In CBP, which spinal region is considered to have the greatest influence on global sagittal balance?