CSCS CSCS: Biomechanics of Resistance 5

Question 1

An athlete performs a bench press with a wide versus narrow grip. The wide grip primarily changes which biomechanical variable?

Accepted Answer

Moment arm at the shoulder joint

Answer

A wider grip reduces the horizontal distance the bar travels and alters the shoulder moment arm, shifting emphasis toward the pectorals over the triceps.

Question 2

The coefficient of static friction between an athlete's shoe and the floor is 0.8, and the athlete weighs 800 N. What is the maximum horizontal force the athlete can exert without sliding?

Accepted Answer

640 N

Answer

Maximum static friction = μs × Normal force = 0.8 × 800 N = 640 N.

Question 3

Which type of muscle contraction produces the greatest peak force at a given velocity?

Accepted Answer

Eccentric

Answer

Eccentric contractions can generate 20–50% more force than isometric contractions because cross-bridges are forcibly stretched, allowing greater tension per bridge.

Question 4

What is the primary reason the deadlift generates higher lumbar compressive forces compared to many other resistance exercises?

Accepted Answer

The load is held far from the body's center of mass, increasing the spinal moment arm

Answer

When the barbell is positioned anterior to the spine, its large moment arm relative to the lumbar joints requires enormous erector spinae forces to maintain posture, increasing compressive load.

Question 5

During a sprint start, an athlete pushes backward and downward against the blocks. According to Newton's third law, the resulting ground reaction force is directed:

Accepted Answer

Forward and upward on the athlete

Answer

Newton's third law states that the reaction force is equal in magnitude and opposite in direction; pushing backward-downward produces a forward-upward ground reaction force on the athlete.

Certified Strength and Conditioning Specialist Practice Test

Certified Strength and Conditioning Specialist Practice Test

CSCS CSCS: Biomechanics of Resistance 5