Question

1. which of the following movements occurs in the frontal plane? *

a. elbow flexion
b. head rotation
c. shoulder abduction
d. knee extension

1. which of the following is the best example of practicing proper body mechanics and injury prevention? *

a. lifting a heavy object by bending at the waist
b. using your back muscles to carry loads
c. taking breaks only after several hours of activity
d. lifting with your legs and maintaining a neutral spine

1. what is the function of the antagonist muscle during movement? *

a. it shortens to create motion
b. it maintains a constant length
c. it opposes the action of the agonist
d. it assists the agonist in contraction

Explanation:

Question 6

To determine which movement occurs in the frontal plane, we analyze each option:

• A. Elbow flexion: Occurs in the sagittal plane (forward/backward movement).
• B. Head rotation: Occurs in the transverse plane (rotational movement).
• C. Shoulder abduction: Involves moving the arm away from the body in the frontal plane (side - to - side movement relative to the body’s front - back axis).
• D. Knee extension: Occurs in the sagittal plane (extending the knee forward/backward).

So, shoulder abduction is the movement in the frontal plane.

For proper body mechanics and injury prevention:

• A. Lifting by bending at the waist: Puts strain on the back, increasing injury risk.
• B. Using back muscles to carry loads: Back muscles are not designed for heavy lifting; this causes strain.
• C. Taking breaks after hours of activity: Prolonged activity without breaks increases fatigue and injury risk.
• D. Lifting with legs and neutral spine: Legs (larger, stronger muscles) handle the load, and a neutral spine avoids back strain, following proper body mechanics.

Thus, option D is the best example.

Regarding the function of the antagonist muscle:

• A. Shortens to create motion: This is the role of the agonist (prime mover) muscle.
• B. Maintains constant length: Not the primary function of the antagonist; it actively opposes or controls the agonist.
• C. Opposes the action of the agonist: Antagonist muscles act in opposition to the agonist (e.g., biceps (agonist) flex the arm, triceps (antagonist) extend it).
• D. Assists the agonist in contraction: This is the role of a synergist muscle, not the antagonist.

So, the antagonist opposes the agonist’s action.

Answer:

C. Shoulder abduction

Question 7