NSCA-CPT Biomechanics 4

Question 1

During a deadlift, excessive forward lean increases the lumbar extensor moment arm. This MOST directly increases:

Accepted Answer

Compressive and shear forces on the lumbar spine

Answer

A greater horizontal distance between the barbell and the lumbar spine increases the torque demand on lumbar extensors, raising both compressive and shear spinal loads.

Question 2

Which of the following BEST describes the angle of pull of a muscle?

Accepted Answer

The angle between the muscle's line of action and the long axis of the bone it moves

Answer

The angle of pull determines how much of the muscle force is directed toward rotation versus compression/distraction of the joint.

Question 3

What happens to angular velocity when a rotating object's moment of inertia decreases (assuming no external torque)?

Accepted Answer

Angular velocity increases

Answer

Conservation of angular momentum (L = Iω) means that if moment of inertia (I) decreases, angular velocity (ω) must increase to keep L constant.

Question 4

Ground reaction force (GRF) during running is typically how many times greater than during walking?

Accepted Answer

2–3 times body weight

Answer

Running produces vertical GRFs of approximately 2–3 times body weight, compared to roughly 1.1–1.5 times during normal walking.

Question 5

The sarcomere length at which maximal active force is produced corresponds to:

Accepted Answer

Optimal actin–myosin cross-bridge overlap

Answer

Peak active force occurs at the sarcomere length where actin and myosin filaments have the greatest number of available cross-bridge binding sites.

NSCA-CPT Exam Practice Test

NSCA-CPT Exam Practice Test

NSCA-CPT Biomechanics 4