CEA Human Anatomy & Biomechanics 2 — Questions and Answers
Question 1: Which spinal region has the greatest range of rotation (axial rotation)?
- Cervical spine
- Thoracic spine (Correct answer)
- Lumbar spine
- Sacral spine
Correct answer: Thoracic spine
The thoracic spine allows the greatest axial rotation due to its rib cage attachment and facet joint orientation.
Question 2: The 'neutral spine' position in ergonomics refers to:
- A fully flexed lumbar curve
- Preservation of the natural lordotic and kyphotic curves (Correct answer)
- Complete elimination of all spinal curves
- Maximum extension of all vertebral segments
Correct answer: Preservation of the natural lordotic and kyphotic curves
Neutral spine preserves the natural S-curve of the spine, minimizing compressive and shear forces on intervertebral discs.
Question 3: Which muscle group is primarily responsible for maintaining upright posture against gravity?
- Hip flexors
- Erector spinae (Correct answer)
- Rectus abdominis
- Hamstrings
Correct answer: Erector spinae
The erector spinae muscles run along the spine and continuously contract to counteract gravitational forward flexion.
Question 4: A worker repeatedly rotates the forearm so the palm faces upward. This motion is called:
- Pronation
- Supination (Correct answer)
- Ulnar deviation
- Radial deviation
Correct answer: Supination
Supination is the rotation of the forearm that turns the palm upward or anteriorly.
Question 5: Which joint type allows the greatest freedom of movement in multiple planes?
- Hinge joint
- Pivot joint
- Ball-and-socket joint (Correct answer)
- Saddle joint
Correct answer: Ball-and-socket joint
Ball-and-socket joints (like the hip and shoulder) allow movement in all three planes: flexion/extension, abduction/adduction, and rotation.
Question 6: Intradiscal pressure in lumbar discs is HIGHEST during which posture?
- Standing upright
- Lying supine
- Sitting with forward lean and no support (Correct answer)
- Walking on a flat surface
Correct answer: Sitting with forward lean and no support
Unsupported forward-leaning seated postures dramatically increase intradiscal pressure due to combined compression and flexion forces.
Question 7: The 'moment arm' in biomechanics refers to:
- The maximum force a muscle can generate
- The perpendicular distance from a joint axis to the line of force (Correct answer)
- The velocity of limb movement during a task
- The length of a lever between two joints
Correct answer: The perpendicular distance from a joint axis to the line of force
The moment arm is the perpendicular distance from the axis of rotation to the applied force, determining the torque produced.
CEA Human Anatomy & Biomechanics 2
Which spinal region has the greatest range of rotation (axial rotation)?