Occupational Therapist Test Biomechanics and Kinesiology 2 — Questions and Answers
Question 1: During normal gait, the stance phase constitutes approximately what percentage of the gait cycle?
- 40%
- 60% (Correct answer)
- 75%
- 50%
Correct answer: 60%
The stance phase, when the foot is in contact with the ground, comprises approximately 60% of the gait cycle, while swing phase accounts for 40%.
Question 2: Torque is calculated as the product of force and:
- Velocity of the moving segment
- Total mass of the limb segment
- The perpendicular distance from the axis of rotation (moment arm) (Correct answer)
- Acceleration of the segment
Correct answer: The perpendicular distance from the axis of rotation (moment arm)
Torque equals force multiplied by the perpendicular distance from the line of force to the axis of rotation (moment arm), determining rotational effect at a joint.
Question 3: The rotator cuff muscles serve which primary biomechanical function at the shoulder?
- Producing shoulder flexion and extension
- Dynamic stabilization of the humeral head within the glenoid fossa (Correct answer)
- Controlling elbow flexion during functional reaching
- Generating scapular protraction and retraction
Correct answer: Dynamic stabilization of the humeral head within the glenoid fossa
The rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) compress the humeral head into the glenoid, providing dynamic glenohumeral joint stability during movement.
Question 4: In spinal biomechanics, the nucleus pulposus of an intervertebral disc functions primarily as:
- A rigid weight-bearing column
- A hydraulic shock absorber that distributes compressive forces (Correct answer)
- A ligamentous stabilizer limiting rotation
- A pain-sensing receptor for compressive load
Correct answer: A hydraulic shock absorber that distributes compressive forces
The gelatinous nucleus pulposus acts as a hydrostatic shock absorber, redistributing compressive loads uniformly across the annulus fibrosus and vertebral end plates.
Question 5: In a healthy standing adult, the center of gravity is typically located:
- At the level of the umbilicus
- At the level of L4–L5
- Anterior to the S2 vertebra (Correct answer)
- At the level of the iliac crest
Correct answer: Anterior to the S2 vertebra
The center of gravity in a standing adult is located approximately anterior to the S2 vertebra, roughly 55–57% of standing height from the floor.
Question 6: Which scapular movement is essential during overhead reaching to maintain adequate subacromial space and prevent impingement?
- Downward rotation
- Scapular retraction
- Upward rotation (Correct answer)
- Scapular depression
Correct answer: Upward rotation
Upward rotation of the scapula during arm elevation directs the glenoid superiorly, maintaining subacromial clearance and allowing full pain-free overhead movement.
Question 7: Optimal elbow angle for seated computer workstation ergonomics is approximately:
- 60–70 degrees of flexion
- 90–100 degrees of flexion (Correct answer)
- 120–130 degrees of flexion
- Full elbow extension
Correct answer: 90–100 degrees of flexion
Elbow flexion of 90–100 degrees at a seated workstation allows the forearms to rest parallel to the floor, minimizing static muscle load and reducing cumulative strain risk.
Occupational Therapist Test Biomechanics and Kinesiology 2
During normal gait, the stance phase constitutes approximately what percentage of the gait cycle?