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

Question 1

Which of the following best describes a third-class lever in the human body?

Accepted Answer

The effort is between the load and the fulcrum, as in flexing the forearm with the biceps brachii.

Question 2

A muscle with fascicles arranged parallel to the long axis of the muscle will have which of the following characteristics?

Accepted Answer

It will have a greater range of motion and can shorten more than other arrangements.

Question 3

Which muscle acts as the agonist during forearm flexion at the elbow joint?

Accepted Answer

Biceps brachii

Question 4

If a muscle is named 'biceps femoris,' what does the name indicate?

Accepted Answer

It has two origins and is located in the thigh.

Question 5

Which of the following best describes the function of a synergist muscle?

Accepted Answer

It assists the agonist by adding extra force or reducing unnecessary movement.

Question 6

A patient is unable to extend their forearm at the elbow. Which muscle is most likely impaired?

Accepted Answer

Triceps brachii

Question 7

Which lever system provides a mechanical advantage, allowing a heavy load to be moved with less effort?

Accepted Answer

Second-class lever with the load between the fulcrum and effort

Question 8

Which muscle shape is described as 'feather-like' with fascicles attaching obliquely to a central tendon?

Accepted Answer

Pennate

Question 9

A muscle named 'extensor carpi radialis longus' is likely to:

Accepted Answer

Extend the wrist and is located on the radius side

Question 10

Which of the following statements about muscle origin and insertion is correct?

Accepted Answer

The insertion moves toward the origin during contraction.

Question 11

Which of the following equations correctly represents the mechanical advantage (MA) of a lever?

Accepted Answer

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

Question 12

Which muscle group is primarily responsible for extending the knee?

Accepted Answer

Quadriceps femoris

Question 13

A muscle that acts as a fixator during a movement:

Accepted Answer

Stabilizes the origin of the agonist to allow efficient movement.

Question 14

Which of the following is an example of a first-class lever in the human body?

Accepted Answer

Raising your head off your chest

Question 15

If a muscle is described as 'deltoid,' what does this indicate about its shape?

Accepted Answer

It is triangular

Question 16

Which of the following best explains why pennate muscles are generally more powerful than parallel muscles?

Accepted Answer

Pennate muscles have more muscle fibers packed into a given length, increasing force.

Question 17

Which muscle is NOT part of the rotator cuff group?

Accepted Answer

Deltoid

Question 18

A patient presents with difficulty abducting their arm at the shoulder. Which muscle is most likely affected?

Accepted Answer

Deltoid

Question 19

Which of the following is the correct order of elements in a second-class lever?

Accepted Answer

Fulcrum-Load-Effort

Question 20

Which muscle is primarily responsible for flexing the thigh at the hip joint?

Accepted Answer

Iliopsoas

The Muscular System: Structure, Function, and Mechanics

Study Guide - Practice Questions