CSCS Resistance Training Biomechanics 3 — Questions and Answers
Question 1: During the bench press, which muscle group acts as the primary agonist?
- Posterior deltoid and rhomboids
- Pectoralis major, anterior deltoid, and triceps brachii (Correct answer)
- Latissimus dorsi and biceps brachii
- Trapezius and serratus anterior
Correct answer: Pectoralis major, anterior deltoid, and triceps brachii
The pectoralis major, anterior deltoid, and triceps brachii are the prime movers during the pressing phase of the bench press.
Question 2: Which plane of motion does a lateral shoulder raise primarily occur in?
- Sagittal plane
- Frontal plane (Correct answer)
- Transverse plane
- Oblique plane
Correct answer: Frontal plane
A lateral (side) shoulder raise moves the arm away from the body's midline in the frontal (coronal) plane.
Question 3: Ground reaction force (GRF) during a vertical jump is best described as:
- The downward force the athlete exerts on the ground
- The equal and opposite force the ground exerts on the athlete (Correct answer)
- The net force produced solely by the quadriceps
- The frictional force opposing horizontal movement
Correct answer: The equal and opposite force the ground exerts on the athlete
GRF is Newton's third law in action — the ground exerts a force equal in magnitude and opposite in direction to the force the athlete applies to the ground.
Question 4: The angle of pennation of a muscle fiber refers to:
- The angle between the muscle's line of pull and the joint's axis of rotation
- The angle between the muscle fibers and the muscle's line of pull (tendon) (Correct answer)
- The degree of curvature in the tendon during maximal contraction
- The angle at which the bone acts as a lever arm
Correct answer: The angle between the muscle fibers and the muscle's line of pull (tendon)
Pennation angle describes the orientation of muscle fibers relative to the line of pull of the tendon, affecting force production and range of motion.
Question 5: Which axis of rotation is associated with transverse plane movements such as internal and external shoulder rotation?
- Frontal (coronal) axis
- Sagittal (anteroposterior) axis
- Longitudinal (vertical) axis (Correct answer)
- Oblique axis
Correct answer: Longitudinal (vertical) axis
Transverse plane rotations (internal/external rotation, pronation/supination) occur around the longitudinal (vertical) axis of the body.
Question 6: In the context of resistance training, 'sticking point' most accurately refers to:
- The moment of peak muscle fiber recruitment
- The joint angle where the mechanical advantage is lowest and lift failure is most likely (Correct answer)
- The point at which elastic energy stored in the bar is released
- The position of maximum muscle length in a movement
Correct answer: The joint angle where the mechanical advantage is lowest and lift failure is most likely
The sticking point is the position in a lift where the ratio of muscle torque to resistance torque is at its minimum, making it the most difficult point to overcome.
Question 7: Which of the following correctly describes a third-class lever system?
- The fulcrum is between the effort and resistance
- The resistance is between the fulcrum and the effort
- The effort is between the fulcrum and the resistance (Correct answer)
- The effort and resistance act at the same point
Correct answer: The effort is between the fulcrum and the resistance
In a third-class lever, the effort (muscle force) is applied between the fulcrum (joint) and the resistance (load), which is the most common arrangement in the human body.
CSCS Resistance Training Biomechanics 3
During the bench press, which muscle group acts as the primary agonist?