Question

During a free weight exercise, muscle force varies with which of the following?

I. Perpendicular distance from the weight to the body joint
II. Joint angle
III. Movement acceleration
IV. Movement velocity squared
A. I and III only
B. II and IV only
C. I, II, III, only
D. II, III, and IV only

Answer 1

Muscle force during a free weight exercise varies with perpendicular distance from the weight to the joint, joint angle, and movement acceleration. Movement velocity squared does not directly affect muscle force in this context, leading to option C as the correct answer.

Step-by-step explanation:

During a free weight exercise, muscle force can vary with the following factors:

• Perpendicular distance from the weight to the body joint
• Joint angle
• Movement acceleration
• However, movement velocity squared is not a direct factor affecting muscle force during most free weight exercises, which typically involve quasistatic movements where inertia plays a minor role.

In physics, these factors relate to torque and lever arm operations. The correct response to the question is option C. I, II, III only.