Contrasting Muscle Motion

Question 1

What is abduction?

Answer 1

Abduction is the movement of a limb(arm or leg) away from the midline of the body (ab- means away from, duct means to lead, and -ion means action). During abduction, the limb moves outward away from the side of the body.

Question 2

An abductor is

Answer 2

A muscle that moves a body part away from the midline.

Question 3

What is adduction?

Answer 3

Adduction is the movement of a limb (arm or leg) toward the midline of the body (ad- means toward, duct means to lead, and -ion means action). During adduction, the limb moves inward toward the side of the body.

Question 4

An adductor is a

Answer 4

Muscle that moves a body part toward the midline.

Question 5

What is flexion?

Answer 5

Flexion means decreasing the angle between two bones by bending a limb at a joint (flex means to bend, and -ion means action).

Question 6

During flexion, the knee or elbow is bent. A flexor muscle bends a limb at

Answer 6

A joint

Question 7

In contrast, extension means

Answer 7

increasing the angle between two bones or the straightening out of a limb (ex- means away from, tens means to stretch out, and -ion means action).

Question 8

During extension, the knee or elbow is straightened. An extensor muscle straightens a

Answer 8

Limb at a joint.

Question 9

What is hyperextension?
Ex?

Answer 9

The extreme or overextension of a limb or body part beyond its normal limit.
Ex: movement of the head far backward or far forward beyond normal range of motion causes hyperextension of the muscles of the neck.

Question 10

What is elevation?
Example?

Answer 10

The act of raising or lifting a body part.
Ex: the elevation of the levator anguli oris muscles of the face raises the corners of the mouth into a smile.

Question 11

A levator is a muscle that

Answer 11

Raises a body part.

Question 12

In contrast, depression is the act of

Answer 12

Lowering a body part.

Question 13

The depressor anguli oris, for example,

Answer 13

Lowers the corner of the mouth into a frown.

Question 14

A depressor muscle ___________ a body part.

Answer 14

Lowers

Question 15

What is rotation?

Answer 15

Rotation is a circular movement around an axis such as the shoulder joint.

Question 16

What is an axis?

Answer 16

An imaginary line that runs lengthwise through the center of the body, and rotation turns a bone on its own axis.

Question 17

In contrast, what is circumduction?
Ex?

Answer 17

The circular movement at the far end of a limb. Ex: the swinging motion of the far end of the arm.

Question 18

What is a rotator muscle?
Example?

Answer 18

Turns a body part on its axis
Ex: head of the humerus, which is the bone of the upper arm, rotates within the shoulder joint.

Question 19

What is the rotator cuff?

Answer 19

The group of muscles and their tendons that hold the head of the humerus securely in place as it rotates within the shoulder joint.

Question 20

What is supination?

Answer 20

The act of rotating the arm or the leg so that the palm of the hand or sole of the foot is turned forward or upward.
Ex: carrying a bowl of soup

Question 21

In contrast, what is pronation?

Answer 21

The act of rotating the arm or leg so that the palm of the hand or sole of the foot is turned downward or backward.

Question 22

What is dorsiflexion?

Answer 22

Is the movement that bends the foot upward at the ankle. Pointing the toes and foot upward decreases the angle between the top of the foot and the front of the leg.

Question 23

In contrast, what is plantar flexion?

Answer 23

The movement that bends the foot downward at the ankle.

Question 24

What does plantar mean?

Answer 24

Plantar means pertaining to the sole of the foot. Pointing the toes and foot downward increases the angle between the top of the the foot and the front of the leg.