OMT Kinesiology & Biomechanics 2 — Questions and Answers
Question 1: Which of the following best defines 'torque' in biomechanics?
- The speed at which a body segment moves
- The tendency of a force to cause rotation around an axis (Correct answer)
- The compressive force on a joint surface
- The linear distance a segment travels
Correct answer: The tendency of a force to cause rotation around an axis
Torque is the rotational effect produced by a force applied at a distance from an axis, calculated as force multiplied by the perpendicular moment arm.
Question 2: During normal gait, which phase accounts for approximately 60% of the gait cycle?
- Swing phase
- Terminal stance
- Stance phase (Correct answer)
- Pre-swing
Correct answer: Stance phase
The stance phase, during which the foot is in contact with the ground, comprises approximately 60% of the total gait cycle.
Question 3: The center of gravity in an average standing adult is located approximately at which level?
- T12 vertebra
- Anterior to S2 vertebra (Correct answer)
- At the umbilicus
- At the iliac crest
Correct answer: Anterior to S2 vertebra
The center of gravity in a standing adult is located approximately anterior to the second sacral (S2) vertebra, roughly at 55–57% of standing height.
Question 4: Which muscle is considered the primary stabilizer of the scapula during upper extremity elevation?
- Pectoralis minor
- Serratus anterior (Correct answer)
- Rhomboid major
- Levator scapulae
Correct answer: Serratus anterior
The serratus anterior is the primary stabilizer of the scapula, protracting it and holding the medial border against the thorax during arm elevation.
Question 5: The scapulohumeral rhythm refers to the ratio of glenohumeral to scapulothoracic motion during arm elevation. What is the commonly accepted ratio?
- 1:1
- 2:1 (Correct answer)
- 3:1
- 4:1
Correct answer: 2:1
The scapulohumeral rhythm has an approximate 2:1 ratio, meaning for every 2 degrees of glenohumeral motion, there is 1 degree of scapulothoracic motion.
Question 6: When a force is applied perpendicular to a bone segment at its midpoint, the resulting bending stress is greatest at which location?
- At the site of force application (Correct answer)
- At the proximal joint
- At the distal joint
- Equally distributed throughout the bone
Correct answer: At the site of force application
Bending stress is greatest at the point where the load is applied perpendicular to the bone's long axis, creating maximum tensile and compressive stresses there.
Question 7: Which type of muscle fiber is characterized by high oxidative capacity, slow-twitch properties, and resistance to fatigue?
- Type IIx fibers
- Type IIa fibers
- Type I fibers (Correct answer)
- Type IIb fibers
Correct answer: Type I fibers
Type I (slow-twitch) muscle fibers have high oxidative (aerobic) capacity, produce lower force, and are highly resistant to fatigue, ideal for endurance activities.
OMT Kinesiology & Biomechanics 2
Which of the following best defines 'torque' in biomechanics?