NSCA-CPT Biomechanics 2 — Questions and Answers
Question 1: Which plane of motion does a lateral raise exercise primarily occur in?
- Sagittal plane
- Frontal plane (Correct answer)
- Transverse plane
- Diagonal plane
Correct answer: Frontal plane
Lateral raises involve shoulder abduction, which occurs in the frontal (coronal) plane.
Question 2: What term describes the rotational effect a force has around an axis?
- Impulse
- Torque (Correct answer)
- Momentum
- Inertia
Correct answer: Torque
Torque (moment of force) is the rotational equivalent of linear force and equals force multiplied by the perpendicular moment arm.
Question 3: During a barbell squat, which joint action occurs at the ankle during the descent phase?
- Plantar flexion
- Inversion
- Dorsiflexion (Correct answer)
- Eversion
Correct answer: Dorsiflexion
The ankle dorsiflexes (toes move toward shin) as the tibia moves forward over the foot during squat descent.
Question 4: The mechanical advantage of a lever system is BEST defined as:
- The ratio of effort arm to resistance arm (Correct answer)
- The ratio of resistance arm to effort arm
- The product of force and velocity
- The sum of all internal moments
Correct answer: The ratio of effort arm to resistance arm
Mechanical advantage equals effort arm divided by resistance arm; a value greater than 1 means less force is needed to move the load.
Question 5: Which type of muscle contraction produces the greatest force output?
- Concentric
- Isometric
- Eccentric (Correct answer)
- Isokinetic
Correct answer: Eccentric
Eccentric contractions generate the highest force because cross-bridges remain attached longer and passive elastic structures (titin) contribute additional tension.
Question 6: A client performs a bicep curl. The elbow joint acts as which class of lever?
- First-class lever
- Second-class lever
- Third-class lever (Correct answer)
- Fourth-class lever
Correct answer: Third-class lever
The elbow is a third-class lever where the effort (biceps insertion) lies between the fulcrum (elbow joint) and the resistance (hand/weight).
Question 7: What is the primary biomechanical purpose of the stretch-shortening cycle (SSC)?
- To increase resting muscle length
- To store and release elastic energy for enhanced force production (Correct answer)
- To reduce joint compressive forces
- To decrease electromyographic activity
Correct answer: To store and release elastic energy for enhanced force production
The SSC stores elastic energy during the eccentric phase and releases it during the concentric phase, amplifying total force output.
NSCA-CPT Biomechanics 2
Which plane of motion does a lateral raise exercise primarily occur in?