$MA = \frac{\text{Effort Arm}}{\text{Resistance Arm}}$

Question 1

Which of the following best describes the role of a fixator muscle during movement?

Accepted Answer

It stabilizes the origin of the prime mover, providing a stable base for movement.

Question 2

During elbow flexion, which muscle acts as the agonist and which acts as the antagonist?

Accepted Answer

Agonist: Biceps brachii; Antagonist: Triceps brachii

Question 3

Which muscle arrangement is best suited for producing the greatest range of motion but the least force?

Accepted Answer

Parallel

Question 4

A patient presents with difficulty abducting the arm at the shoulder. Which muscle and nerve are most likely affected?

Accepted Answer

Deltoid muscle; Axillary nerve

Question 5

Which of the following is the correct origin and insertion for the pectineus muscle?

Accepted Answer

Origin: Pubic bone; Insertion: Pectineal line of femur

Question 6

Which equation correctly represents the mechanical advantage of a lever system in the musculoskeletal system?

Accepted Answer

$MA = \frac{	ext{Effort Arm}}{	ext{Resistance Arm}}$

Question 7

Which muscle is the prime mover for hip flexion and what is its innervation?

Accepted Answer

Iliopsoas; Femoral nerve

Question 8

Which muscle group is responsible for knee extension and what is their common innervation?

Accepted Answer

Quadriceps femoris; Femoral nerve

Question 9

Which of the following muscles is NOT part of the rotator cuff?

Accepted Answer

Teres major

Question 10

A patient with injury to the phrenic nerve will most likely have difficulty with which function?

Accepted Answer

Breathing due to impaired diaphragm contraction

Question 11

Which muscle arrangement allows for the greatest force production?

Accepted Answer

Multipennate

Question 12

Which muscle acts as a synergist during elbow flexion?

Accepted Answer

Brachioradialis

Question 13

Which nerve innervates the muscles of facial expression?

Accepted Answer

Facial nerve (CN VII)

Question 14

Which muscle is the prime mover for plantar flexion at the ankle?

Accepted Answer

Gastrocnemius

Question 15

Which muscle is responsible for protracting the scapula and is commonly associated with 'scapular winging'?

Accepted Answer

Serratus anterior

Question 16

Which muscle is the antagonist to the hamstrings during hip extension?

Accepted Answer

Iliopsoas

Question 17

Which of the following is a function of the pelvic diaphragm?

Accepted Answer

Supports pelvic organs and maintains continence

Question 18

Which muscle is the prime mover for dorsiflexion of the ankle?

Accepted Answer

Tibialis anterior

Question 19

Which muscle is responsible for flexing the forearm at the elbow and is innervated by the musculocutaneous nerve?

Accepted Answer

Brachialis

Question 20

Which muscle group is responsible for adducting the thigh and what is their common innervation?

Accepted Answer

Adductor group; Obturator nerve

Skeletal Muscular System: Functional Groupings and Muscle Actions

Study Guide - Practice Questions